**2. Experimental section**

In general, monocrystalline grains, used for tools with vitrified bond are assigned for grinding of flat and shaped surfaces, for example grinding of internal surfaces of Titan alloys and sharpening (fig. 2). Microcrystalline grains are complexes consisting of collection of small microcrystals with sizes ranging from one to a few microns, characterized by a higher

mechanical strength, and higher ductility of monocrystalline grains (fig. 3)

**Figure 2.** Microcrystalline diamond grains magn.: a) 400x, b) 2000x

56 Sintering Techniques of Materials

**Figure 3.** Monocrystalline diamond grains magn.: a) 200x, b) 2000

The microcrystalline grains are recommended for grinding operations, where surface quality is the main processing criterion. The fillers can be alumina, silicon carbide, tungsten, zirconium silicate etc. It is assumed that the filler, introduced into the binder, protects the seed prior to the dynamic action of chips (typically having a higher temperature) and that increases the strength properties of the sinter, the thermal resistance and wear resistance, also taking part

#### **2.1. Part I Preparation and study of some physical and mechanical properties of glasses**

#### *2.1.1. The starting materials and methods of research*

The study selected five variants of glasses from the Si02-Al203-B203-Na20-Ba0 system. The following were used as starting materials:


After accurate grinding, sieving through a 0.63mm sieve and mixed, raw materials were placed in corundum crucibles and heated at a temperature above 1,350° C. After fritting (hot melt glass pouring into cold water) and once again the glass was milled and sieved. All glass frits were completely transparent with bluish color. On the received materials the following tests were carried out:


#### *2.1.2. Results and discussion*

Test glass belonged to the group of light, characterized by a low density, ranging between 2.34 (W4), and 2.69 g/cm3 (Ba23bis). It was evident that with the reduction of silicon dioxide content in the glass, decreasing the density of the glass increased A slight increase in the content of barium oxide, the constant of silicon dioxide and reduced alumina content did not affect significantly the increase in density. The results are summarized in Table 2


**Table 2.** The density of the tested glasses

### *2.1.3. Calculations of thermodynamic stability of the glasses by algorithm VCS*

After accurate grinding, sieving through a 0.63mm sieve and mixed, raw materials were placed in corundum crucibles and heated at a temperature above 1,350° C. After fritting (hot melt glass pouring into cold water) and once again the glass was milled and sieved. All glass frits were completely transparent with bluish color. On the received materials the following tests

**•** the density of helium, on Accu Pyc II 1340V10 helium pycnometer using 5 parallel samples;

**•** the X-ray diffractometer of Panalytical Empiriam with copper lamp in the range of 2 theta

**•** calculation of thermodynamic stability using algorithm VCS for sets of glasses in tempera‐ tures of 700, 900, 1300 and 1500° C on two assumptions: the total miscibility of liquid and

**•** the reactivity of raw materials of glasses and the melt glasses using differential scanning

**•** the wettability of glasses to the substrate of silicon carbide or sintered alumina (cubitron) on the high-temperature microscope of Leitz -Watzler type by sessile-drop method.

**•** the three-point bending strength of trabecular glass, describing the work of destruction by

Test glass belonged to the group of light, characterized by a low density, ranging between 2.34

in the glass, decreasing the density of the glass increased A slight increase in the content of barium oxide, the constant of silicon dioxide and reduced alumina content did not affect

(Ba23bis). It was evident that with the reduction of silicon dioxide content

**]**

**•** microscopic observation (SEM)of transverse specimens after testing the wettability

vapor phases or total immiscibility liquid and vapor phases;

**•** the Young's modulus of glass using a flaw with the head broadband

significantly the increase in density. The results are summarized in Table 2

**The variant of glasses Density [g/cm3**

W1 2,4548 W2 2,5347 W3 2,4320 W4 2,3426 Ba 23 bis 2,6912

calorimetry (DSC-device STA-449 F3 Jupiter)

using a machine Zwick Roell Z2.5

*2.1.2. Results and discussion*

**Table 2.** The density of the tested glasses

(W4), and 2.69 g/cm3

were carried out:

58 Sintering Techniques of Materials

angle of 5 to 90 degrees;

Chemical stability of the connections between components of the glasses was determined by calculation of the thermodynamic potential of components by VCS algorithm, which takes into account the probable stability of the reaction products. Equilibria calculations were performed for the four variants of the glasses of the SiO2-Al2O3-BaO-B2O3-Na2O system in temperatures 700° C, 900° C, 1,350° C, 1500° C at atmospheric pressure 1013 hPa. The molar ratios of the components were adopted taking into account their actual values. It was assumed that the component of glass within these ranges of temperatures may occur: in a multicomponent gas phase and condensed phase pure (liquid and solid). It is not known whether the active phase pure liquid form (that are immiscible with each other) or a liquid phase formed of unlimited miscibility, therefore, the calculation was performed by two assumptions out. Of the approx‐ imately 100 likely stable compounds there were 10, of which the solid 3. Summary of solid stable compounds glass as an example of option 2 are shown in Tables 3 and 4.


**Table 3.** Calculation of the thermodynamic stability of glass precursors, option 1 assumption 1

According with the first assumption at high temperatures (1350, 1500° C) there should be stable three compounds: an aluminum borosilicate (Al6BSi2O13), barium silicate (BaSi2O5) and silicon dioxide (SiO2). In the second assumption the second barium silicate (BaSi2O5) presented only one. Similarly were in the other glasses. The verification of the existence of these compounds in the glass was carried out on the basis of X-ray examination.


**Table 4.** Calculation of the thermodynamic stability of glass precursors, option 1 assumption 2

#### *2.1.4. X-ray research of the glasses*

The study of X-ray glasses clearly showed amorphous structure, as evidenced increase in the background at low angles and lack of educated, sharp peaks throughout the angular range. (fig. 4-X-ray glasses of W1). The existence of crystalline barium silicate (Al6BSi2O13) was not found.

**Figure 4.** An example of X-ray glass, variant W1

#### *2.1.5. Differential scanning calorimetry research*

Thermal analysis of the five types of the glass raw materials and glass of W1 variant was based on differential scanning calorimetry. This method consisted of recording energy required to bring to zero the difference in temperature of the test sample and the reference material as a function of temperature or time.[14] The shape of the DSC curve showed a good agreement with the DTA curve. Endothermic peak was created when the sample temperature was below the standard, and the exothermic peak, when the temperature of the sample was higher than the reference. Samples containing a mixture of raw materials (precursors) of glass heated at a rate of 5° C/min to a temperature of 1400° C. When analyzing the plots, it can be concluded that the incomplete decomposition of the raw materials with the separation of water or CO2 to a temperature of 350°C occurred, as reflected by the different endothermic peaks. The earliest release of the water of hydration of aluminum nitrate (variant W2-71,0o C, 80,0o C), followed by water coming from the decomposition of boric acid (W1-127,3o C) and CO2 from the decomposition of sodium carbonate. At a temperature of 548o C on curves of W2 and Ba23 bis inflection appeared to indicate polymorphic transitions of silicon dioxide with the appear‐ ance of high gamma phase. For all graphs at about 1230° C and above the melting peak of barium carbonate was observed. Full homogenization mixture of precursors occurred above 1,350° C (W1-DSC chart in fig. 5 and 6)

The New Generation of Diamond Wheels with Vitrified (Ceramic) Bonds http://dx.doi.org/10.5772/59503 61

**Figure 5.** DSC curves of glass raw materials, variant W1

(fig. 4-X-ray glasses of W1). The existence of crystalline barium silicate (Al6BSi2O13) was not

Thermal analysis of the five types of the glass raw materials and glass of W1 variant was based on differential scanning calorimetry. This method consisted of recording energy required to bring to zero the difference in temperature of the test sample and the reference material as a function of temperature or time.[14] The shape of the DSC curve showed a good agreement with the DTA curve. Endothermic peak was created when the sample temperature was below the standard, and the exothermic peak, when the temperature of the sample was higher than the reference. Samples containing a mixture of raw materials (precursors) of glass heated at a rate of 5° C/min to a temperature of 1400° C. When analyzing the plots, it can be concluded that the incomplete decomposition of the raw materials with the separation of water or CO2 to a temperature of 350°C occurred, as reflected by the different endothermic peaks. The

earliest release of the water of hydration of aluminum nitrate (variant W2-71,0o

the decomposition of sodium carbonate. At a temperature of 548o C on curves of W2 and Ba23 bis inflection appeared to indicate polymorphic transitions of silicon dioxide with the appear‐ ance of high gamma phase. For all graphs at about 1230° C and above the melting peak of barium carbonate was observed. Full homogenization mixture of precursors occurred above

followed by water coming from the decomposition of boric acid (W1-127,3o

C, 80,0o

C) and CO2 from

C),

found.

60 Sintering Techniques of Materials

**Figure 4.** An example of X-ray glass, variant W1

1,350° C (W1-DSC chart in fig. 5 and 6)

*2.1.5. Differential scanning calorimetry research*

**Figure 6.** DSC curves of glass, variant W1

Analyzing the DSC plot of W1 glass could be seen of his amorphous. The inflection of the curve reported that there was at 542o C vitrification and 649,8o C started the process of softening. On the thermogravimetric curve TG were not visible weight loss upon heating the glass.

#### *2.1.6. Wettability research of glasses*

The study of wettability of glasses to substrates of silicon carbide or submicrocrystalline sintered corundum is performed using high-temperature microscope of Leitz- Watzler, type using sessile drop method. Silicon carbide is used as a filler in diamond grinding wheels or supporting grain. SiC substrate, there was degassed under vacuum, and therefore contain adsorbed gases from the air (oxygen, nitrogen), and chronic alcohol bath defatted not entirely C vitrification and 649,8<sup>o</sup>

**Wettability research of glasses** 

542<sup>o</sup>

970<sup>o</sup> C).

surface. Therefore, the observed high temperature sintering (for all variants within 620-670o C glasses) and the temperature drops propagation (920-970o C). The study of wettability of glasses to substrates of silicon carbide or submicrocrystalline sintered corundum is performed using high-temperature microscope of Leitz- Watzler, type using sessile drop method. Silicon carbide is used as a filler in diamond grinding wheels or supporting grain. SiC substrate, there was degassed under vacuum, and therefore contain adsorbed gases from the air (oxygen, nitrogen), and chronic alcohol bath defatted not entirely surface. Therefore, the

Figure 6. DSC curves of glass, variant W1 Analyzing the DSC plot of W1 glass could be seen of his amorphous. The inflection of the curve reported that there was at

C started the process of softening. On the thermogravimetric curve TG were not visible weight

C glasses) and the temperature drops propagation (920-

Figure 7. Wetting of cubitron substrate by glass, W1 variant

**Figure 7.** Wetting of cubitron substrate by glass, W1 variant

observed high temperature sintering (for all variants within 620-670o

substrate better than the silicon carbide substrate, at lower temperatures (880-930o C), although the same procedure of

**Figure 8.** Wetting of silicon carbide substrate by glass, W1 variant

degreasing were conducted.

Contact angle theta ranged less than 40 degrees. All the tested glass wetted submicrocrystalline sintered corundum (cubitron) substrate better than the silicon carbide substrate, at lower temperatures (880-930o C), although the same procedure of degreasing were conducted.

#### *2.1.7. Mapping of the surface of glass-substrate microsection*

Microscopic observation of transverse cross-sectional views of the glass –SiC substrate or glasssubmicrocrystalline sintered corundum substrate carried out using a scanning electron microscope JSM 6460LV and starters EDS (Energy – dispersive X-ray spectroscopy analyzer) revealed the presence of a small transition layer in the system glass- submicrocrystalline sintered corundum (pictures of the glass Ba23 bis-submicrocrystalline sintered corundum) contains barium elements. The phenomena of interlayer (fig. 9) in the case of specimens glasssilicon carbide substrate comprising this was much wider probably resulted from the presence of silicon, both in the glass and substrate.

surface. Therefore, the observed high temperature sintering (for all variants within 620-670o C

C T = 766<sup>o</sup>

C T = 758o

Figure 7. Wetting of cubitron substrate by glass, W1 variant

Figure 8. Wetting of silicon carbide substrate by glass, W1 variant

Contact angle theta ranged less than 40 degrees. All the tested glass wetted submicrocrystalline sintered corundum (cubitron) substrate better than the silicon carbide substrate, at lower temperatures (880-930o C), although the same procedure of

Contact angle theta ranged less than 40 degrees. All the tested glass wetted submicrocrystalline sintered corundum (cubitron) substrate better than the silicon carbide substrate, at lower

Microscopic observation of transverse cross-sectional views of the glass –SiC substrate or glasssubmicrocrystalline sintered corundum substrate carried out using a scanning electron microscope JSM 6460LV and starters EDS (Energy – dispersive X-ray spectroscopy analyzer) revealed the presence of a small transition layer in the system glass- submicrocrystalline sintered corundum (pictures of the glass Ba23 bis-submicrocrystalline sintered corundum) contains barium elements. The phenomena of interlayer (fig. 9) in the case of specimens glasssilicon carbide substrate comprising this was much wider probably resulted from the presence

C), although the same procedure of degreasing were conducted.

The study of wettability of glasses to substrates of silicon carbide or submicrocrystalline sintered corundum is performed using high-temperature microscope of Leitz- Watzler, type using sessile drop method. Silicon carbide is used as a filler in diamond grinding wheels or supporting grain. SiC substrate, there was degassed under vacuum, and therefore contain adsorbed gases from the air (oxygen, nitrogen), and chronic alcohol bath defatted not entirely surface. Therefore, the

Figure 6. DSC curves of glass, variant W1 Analyzing the DSC plot of W1 glass could be seen of his amorphous. The inflection of the curve reported that there was at

C).

C T = 934<sup>o</sup>

C T = 965o

C glasses) and the temperature drops propagation (920-

C

C

C started the process of softening. On the thermogravimetric curve TG were not visible weight

glasses) and the temperature drops propagation (920-970o

observed high temperature sintering (for all variants within 620-670o

T = 260o

**Figure 7.** Wetting of cubitron substrate by glass, W1 variant

**Figure 8.** Wetting of silicon carbide substrate by glass, W1 variant

*2.1.7. Mapping of the surface of glass-substrate microsection*

of silicon, both in the glass and substrate.

T = 30o

542<sup>o</sup>

970<sup>o</sup> C).

C vitrification and 649,8<sup>o</sup>

loss upon heating the glass. **Wettability research of glasses** 

62 Sintering Techniques of Materials

degreasing were conducted.

temperatures (880-930o

**Figure 9.** Picture of mapping of the surface of glass-substrate microsection – Ba23 bis variant

#### *2.1.8. Testing the strength of glass*

Flexural testing was performed on the four groups of glasses for Zwick Roell Z2.5 machine, at the test speed of 0.5 mm/min, and the spacing supports 34 mm The flexural modulus was determined for all samples by the secant, taking reference points as a force of 50 N and 100 N start the end (Table 5). Maximum bending strength in the range of 100 MPa was obtained for the samples of glass W1 and Ba23 bis. For a group of glasses W4 and W3 it was lower by half. This can be explained by the reduced content of primarily silicon dioxide in these glasses. Similar behavior was observed in the samples of the destruction operation. The largest value of the work of destruction (W1-19,27 N/mm) was obtained for samples W1 and three times lower for samples W3.


**Table 5.** Measurement of flexural strength of glass

#### *2.1.9. Young modulus measurement of glasses*

The measurements were carried out on the test bench equipped with a flaw, heads broadband and a PC with installed software. Young's modulus and Poisson's ratio of the samples based on the determined velocity of the longitudinal wave and transverse density of the material. All calculations were performed using the program Modulus 1.0. The highest values obtained of glass Ba23 bis (87 GPa) (Table 6). Poisson's ratio for all glasses were the same (0.38).


**Table 6.** Measurement results of Young modulus

#### **2.2. Part II Operational tests of grinding wheels containing the newly developed glass**

#### *2.2.1. The starting materials and methods of research*

After summarizing the results of studies on the physical and mechanical properties of the newly developed glass, two of them with the best value properties (Ba23 bis and W1) were selected and used to develop the recipe wheel. Test wheels were prepared to carry out grinding tests. Grinding of flank surface of BNDCC composite samples was performed using wheels 6A2 100x10x4 mm type, containing uncoated diamond grain, Lands LS120 (D46-45-38 microns) type or LS 600F (D25-20-30 microns) with higher concentration of diamond (C125%) and a W1 or Ba23 bis binder (Fig. 9b).

Using DOE, influence on surface roughness and process efficiency of following parameters was derived:


Constant parameters during experiments were:


**•** maschining time of the one cycle, t = 600 s, • grinding wheel peripheral speed, vs = 12, 15, 20 m / s • working engagement ae: 0.002, 0.005, 0.01 mm / double stroke of the table

Name of samples

Ba 23 bis glass

**Part II Operational tests of grinding wheels containing the newly developed glass** 

Poisson's ratio

W1 glass 0.38 79 2,2 W3 glass 0.38 79 2,2 W4 glass 0.38 76 6,2

Young modulus [GPa]

0.38 87 5,8

After summarizing the results of studies on the physical and mechanical properties of the newly developed glass, two of them with the best value properties ( Ba23 bis and W1) were selected and used to develop the recipe wheel. Test wheels were prepared to carry out grinding tests. Grinding of flank surface of BNDCC composite samples was performed using wheels 6A2 100x10x4 mm type, containing uncoated diamond grain, Lands LS120 (D46-45-38 microns) type or LS 600F (D25-20-

Modulus uncertenainty

[%]


Table 6. Measurement results of Young modulus

**The starting materials and methods of research** 

**•** BNDCC composites • the characteristics and dimensions of the grinding type 6A2 100x10x4 mm • the type of coolant-fed Synkom PGA

10b).

*2.1.9. Young modulus measurement of glasses*

64 Sintering Techniques of Materials

**Table 6.** Measurement results of Young modulus

or Ba23 bis binder (Fig. 9b).

**•** diamond grain D46, D25

was derived:

*2.2.1. The starting materials and methods of research*

**•** grinding wheel peripheral speed, vs = 12, 15, 20 m / s

**•** a research position with the universal tool grinder 3E642,

Constant parameters during experiments were:

**•** the type of coolant-fed Synkom PGA

**•** the method by pouring coolant

**•** working engagement ae: 0.002, 0.005, 0.01 mm / double stroke of the table

**•** the characteristics and dimensions of the grinding type 6A2 100x10x4 mm

The measurements were carried out on the test bench equipped with a flaw, heads broadband and a PC with installed software. Young's modulus and Poisson's ratio of the samples based on the determined velocity of the longitudinal wave and transverse density of the material. All calculations were performed using the program Modulus 1.0. The highest values obtained of glass Ba23 bis (87 GPa) (Table 6). Poisson's ratio for all glasses were the same (0.38).

**Name of samples Poisson's ratio Young modulus [GPa] Modulus uncertenainty [%]**

**2.2. Part II Operational tests of grinding wheels containing the newly developed glass**

After summarizing the results of studies on the physical and mechanical properties of the newly developed glass, two of them with the best value properties (Ba23 bis and W1) were selected and used to develop the recipe wheel. Test wheels were prepared to carry out grinding tests. Grinding of flank surface of BNDCC composite samples was performed using wheels 6A2 100x10x4 mm type, containing uncoated diamond grain, Lands LS120 (D46-45-38 microns) type or LS 600F (D25-20-30 microns) with higher concentration of diamond (C125%) and a W1

Using DOE, influence on surface roughness and process efficiency of following parameters

W1 glass 0.38 79 2,2 W3 glass 0.38 79 2,2 W4 glass 0.38 76 6,2 Ba 23 bis glass 0.38 87 5,8 The study was carried out on a modernized grinding universal tool grinder 3E642 (fig. 10a), equipped with stepless speed control of the wheel and the cooling system. Grinding process was carried out with cooling by spraying a 2% solution of PGA Synkon coolant concentrate in tap water. • the method by pouring coolant • maschining time of the one cycle, t = 600 s, • number of the table double strokes – 3 • table feed speed, vf = 210 mm / min • BNDCC composites

Using DOE, influence on surface roughness and process efficiency of following parameters was derived:

To test of the efficiency of grinding process of custom BNDCC composite sample (boron nitride dispersive in cemented carbide), comprising weight 20% of the grains of cubic boron nitride, with granulation 4-8 mm and dimensions 19x5,7 mm from the edge intersected at a distance of 1 mm from the end, were made at the Warsaw Univeristy of Technology, at the Faculty of Materials Science and Engineering. Before attempts to work the sample was adhered to the brackets in order to attach them to the machine (fig. 10c). Below the picture shows the position of the test, the wheel and bonded composites (fig. 10b). The study was carried out on a modernized grinding universal tool grinder 3E642 (fig. 10a), equipped with stepless speed control of the wheel and the cooling system. Grinding process was carried out with cooling by spraying a 2% solution of PGA Synkon coolant concentrate in tap water. To test of the efficiency of grinding process of custom BNDCC composite sample (boron nitride dispersive in cemented carbide), comprising weight 20% of the grains of cubic boron nitride, with granulation 4-8 mm and dimensions 19x5,7 mm from the edge intersected at a distance of 1 mm from the end, were made at the Warsaw Univeristy of Technology, at the Faculty of Materials Science and Engineering. Before attempts to work the sample was adhered to the brackets in order to attach them to the machine (fig. 10c). Below the picture shows the position of the test, the wheel and bonded composites (fig.

Ba23 bis c) composites BNDCC intended for research **Figure 10.** a) The position of a universal tool grinder 3E642 grinding tests with cooling, b) diamond grinding wheel vitrified Ba23 bis c) composites BNDCC intended for research

Figure 10. a) The position of a universal tool grinder 3E642 grinding tests with cooling, b) diamond grinding wheel vitrified

Measured: the height of abraded material m, height of wheel. Calculated: the volume of abraded material Vw, consumption volume Vs wheel, radial wheel wear Vrs, grinding ratio G, yield losses of (volumetric) Qw, proper performance defects Q'w (deficient performance attributable on the active wheel width).

Sample mass measurements were carried out before and after each treatment using a laboratory scale with an accuracy of measurement 0.001 g. Measurements of the height of wheels and work-before and after each test was performed using electronic calipers accurate to 0.01 mm.

For the measurement of surface topography work-pieces profiler workshop was used. Before and after test were performed via research work on modul profilometer TOPO 01vP designed for measurement and analysis of surface roughness and waviness profiles and the profile of the actual surface without filtration with the program PROFILE. Images of 2D, 3D, marked elevation values Rz, Rt , Ra and horizontal parameters W, St, Sa in accordance with PN-EN ISO 4287th were conducted. The microscopic observations (SEM) of the samples before and after grinding were made. The designated function of the object of research in the form of a polynomial of the second degree of interaction, allowed to determine the statistical relationship between the basic parameters of the treatment and its effects (surface roughness).

#### *2.2.2. Results and discussion*

The results of grinding tests of D46 diamond grinding wheels with newly developed binders worked at a peripheral speed of 12, 15, 20 m / s and depth of grinding 0.002, 0.005 mm/double stroke of the table. were presented in Tables 7-8 and figures (fig. 11-16). It was evident that both: the D46 Ba23 bis wheel andW1 D46 wheel were best operating at a depth of 0.005 mm grinding/double stroke. The uniform wear of diamond grains and their self-sharpening were demonstrated.

The grinding wheels with D25 grit size of diamond grains worked at a speed of 15m/s and depth of grinding 0.002 and 0.005 mm/double stroke. All the grinding performance parameters were comparable for both types of wheels. Better results were obtained by D25 grinding wheels with Ba23 bis binder. For the depth of the grinding process the surface roughness of machined BNDCC composites varied within the same limits 0.02-0.03 μm. Comparing the results of performance parameters of the process of grinding wheels with the D46 and D25 granulation can state that they were very similar. Slightly better results were obtained with the wheels with lower diamond grit size (D25).


**Table 7.** Results of performance parameters of the process of grinding the surface of composites BNDCC 3,14 D46 grinding wheel W1, Ba23 bis, vs = 12, 15, 20 m/s with working engagement ae = 0,002 mm

For the measurement of surface topography work-pieces profiler workshop was used. Before and after test were performed via research work on modul profilometer TOPO 01vP designed for measurement and analysis of surface roughness and waviness profiles and the profile of the actual surface without filtration with the program PROFILE. Images of 2D, 3D, marked

4287th were conducted. The microscopic observations (SEM) of the samples before and after grinding were made. The designated function of the object of research in the form of a polynomial of the second degree of interaction, allowed to determine the statistical relationship

The results of grinding tests of D46 diamond grinding wheels with newly developed binders worked at a peripheral speed of 12, 15, 20 m / s and depth of grinding 0.002, 0.005 mm/double stroke of the table. were presented in Tables 7-8 and figures (fig. 11-16). It was evident that both: the D46 Ba23 bis wheel andW1 D46 wheel were best operating at a depth of 0.005 mm grinding/double stroke. The uniform wear of diamond grains and their self-sharpening were

The grinding wheels with D25 grit size of diamond grains worked at a speed of 15m/s and depth of grinding 0.002 and 0.005 mm/double stroke. All the grinding performance parameters were comparable for both types of wheels. Better results were obtained by D25 grinding wheels with Ba23 bis binder. For the depth of the grinding process the surface roughness of machined BNDCC composites varied within the same limits 0.02-0.03 μm. Comparing the results of performance parameters of the process of grinding wheels with the D46 and D25 granulation can state that they were very similar. Slightly better results were obtained with the wheels with

**Peripheral speed of wheel**

D46 Ba23 bis 1,35 0,14 3,41 0,03

D46 Ba23 2,29 0,23 29,48 0,03

D46 Ba23 1,31 0,13 17,91 0,03

**Table 7.** Results of performance parameters of the process of grinding the surface of composites BNDCC 3,14 D46

**Qw, x10-3 mm3 /s**

**Q'w, x10-3 mm3**

1,32 0,13 13,56 0,03

2,30 0,23 31,12 0,03

1,19 0,12 12,02 0,03

**/ mm·s G [-] Ra, µm**

**vs, m/s**

12

15

20

grinding wheel W1, Ba23 bis, vs = 12, 15, 20 m/s with working engagement ae = 0,002 mm

between the basic parameters of the treatment and its effects (surface roughness).

, Ra and horizontal parameters W, St, Sa in accordance with PN-EN ISO

elevation values Rz, Rt

66 Sintering Techniques of Materials

*2.2.2. Results and discussion*

lower diamond grit size (D25).

**Kind of wheelWorking engagement ae, mm**

0,002

demonstrated.

D46 W1

D46 W1

D46 W1

**Figure 11.** The diagram of material removal rate Qw, x10-3 mm3 / s after grinding of the surface of composites BNDCC 3,14 samples with D46 W1 and Ba23 bis grinding wheels with working engagement ae: 0.002 mm/double stroke of the table

**Figure 12.** The diagram of material removal rate per unit active grinding wheel width Q'w, x10-3mm3 /mm⋅s after grinding of the surface of of composites BNDCC 3,14 samples with D46 W1 and Ba23 bis grinding wheels with work‐ ing engagement ae: 0.002 mm/double stroke of the table

**Figure 13.** The diagram of grinding ratio G, mm3 /mm3 for grinding wheels with working engagement ae 0.002 mm/ double stroke of the table


**Table 8.** Results of performance parameters of the process of grinding the surface of composites BNDCC 3,14 D46 grinding wheel W1, Ba23 bis, vs = 12, 15, 20 m /s with working engagement ae = 0,005 mm

**Figure 14.** The diagram of material removal rate Qw, x10-3 mm3 /s after grinding of the surface of composites BNDCC 3,14 samples with D46 W1 and Ba23 bis grinding wheels with working engagement ae: 0.005 mm/double stroke of the table

**Figure 15.** The diagram of material removal rate per unit active grinding wheel width Q'w, x10-3mm3 /mm⋅s after grinding of the surface of composites BNDCC 3,14 samples with D46 W1 and Ba23 bis grinding wheels with working engagement ae: 0.005 mm/double stroke of the table

**Kind of wheelWorking engagement ae, mm**

68 Sintering Techniques of Materials

0,005

**Figure 14.** The diagram of material removal rate Qw, x10-3 mm3

engagement ae: 0.005 mm/double stroke of the table

D46 W1

D46 W1

D46 W1

table

**Peripheral speed of wheel**

12

D46 Ba23 1,27 0,13 5,88 0,03

15

D46 Ba23 2,23 0,22 26,94 0,03

20

D46 Ba23 1,21 0,12 16,94 0,03

**Table 8.** Results of performance parameters of the process of grinding the surface of composites BNDCC 3,14 D46

3,14 samples with D46 W1 and Ba23 bis grinding wheels with working engagement ae: 0.005 mm/double stroke of the

**Figure 15.** The diagram of material removal rate per unit active grinding wheel width Q'w, x10-3mm3

grinding of the surface of composites BNDCC 3,14 samples with D46 W1 and Ba23 bis grinding wheels with working

**Qw, x10-3 mm3 /s**

**Q'w, x10-3 mm3 /mm·s**

1,24 0,12 17,39 0,03

2,25 0,23 15,24 0,03

1,13 0,11 7,82 0,02

/s after grinding of the surface of composites BNDCC

/mm⋅s after

**G Ra, µm**

**vs, m/s**

grinding wheel W1, Ba23 bis, vs = 12, 15, 20 m /s with working engagement ae = 0,005 mm

**Figure 16.** The diagram of grinding ratio G, mm3 /mm3 for grinding wheels with working engagement ae 0.005 mm/ double stroke of the table


**Table 9.** Results of performance parameters of the process of grinding the surface of composites BNDCC 3,13 D25 grinding wheel W1, Ba23 bis, vs = 15 m/s

**Figure 17.** The diagram of material removal rate Qw, x10-3mm3 /s after grinding of the surface of composites BNDCC 3,13 samples with D25 W1 and Ba23 bis grinding wheels with working engagement ae: 0.002, 0.005 mm/double stroke of the table

**Figure 18.** The diagram of material removal rate per unit active grinding wheel width Q'w, x10-3 mm3 /mm⋅s after grinding of the surface of composites BNDCC 3,13 samples with D25 W1 and Ba23 bis grinding wheels with working engagement ae: 0.002, 0.005 mm/double stroke of the table

#### *2.2.3. Research of geometric structure of BNDCC composites*

The study of geometric structure of the samples before and after grinding showed that the assumed test conditions are properly selected (Figure 20a). Machining by grinding the assumed operating parameters of wheel allowed to obtain roughness parameters (Ra, Rz, Rt ) times better than the initial (Ra before 1.28-1.40 μm, Ra after-0,018-0,04 μm, Rz before 7,05-7,890 μm, Rz after 0,126-0,150 μm). Image of 3D surface of the BNDCC composite before grinding process showed the presence of significant inequalities (fig. 20a). After grinding process the surface was completely inequalities (fig. 20b).

The New Generation of Diamond Wheels with Vitrified (Ceramic) Bonds http://dx.doi.org/10.5772/59503 71

Figure 20. The results of the surface roughness of the composite BNDCC polished 1.47 grinding D25 Ba23: a) before grinding, b) after grinding **Figure 20.** The results of the surface roughness of the composite BNDCC polished 1.47 grinding D25 Ba23: a) before grinding, b) after grinding

#### **The microscopic image of BNDCC composite**  *2.2.4. The microscopic image of BNDCC composite*

**The mathematical model of the function of research object** 

a) b)

The samples of BNDCC composites were observed under a scanning microscope before and after the grinding tests. For all composite samples before grinding process parallel scratches were visible on the surface of the samples. These were probably established through their mechanical treatment after sintering. Microscope image of the samples after grinding showed sharply defined edges with blunted of blade grains in carbide matrix. The samples of BNDCC composites were observed under a scanning microscope before and after the grinding tests. For all composite samples before grinding process parallel scratches were visible on the surface of the samples. These were probably established through their mechanical treatment after sintering. Microscope image of the samples after grinding showed sharply defined edges with blunted of blade grains in carbide matrix.

Figure 21. Microscope image of composite BNDCC: a) before; b) after the treatment grinding D46 Ba23 bis binder

a)

**Figure 18.** The diagram of material removal rate per unit active grinding wheel width Q'w, x10-3 mm3

/mm3

The study of geometric structure of the samples before and after grinding showed that the assumed test conditions are properly selected (Figure 20a). Machining by grinding the assumed operating parameters of wheel allowed to obtain roughness parameters (Ra, Rz, Rt

times better than the initial (Ra before 1.28-1.40 μm, Ra after-0,018-0,04 μm, Rz before 7,05-7,890 μm, Rz after 0,126-0,150 μm). Image of 3D surface of the BNDCC composite before grinding process showed the presence of significant inequalities (fig. 20a). After grinding process the

for grinding wheels with working engagement ae 0.002 and

engagement ae: 0.002, 0.005 mm/double stroke of the table

70 Sintering Techniques of Materials

**Figure 19.** The diagram of grinding ratio G, mm3

surface was completely inequalities (fig. 20b).

*2.2.3. Research of geometric structure of BNDCC composites*

0.005 mm/double stroke of the table

grinding of the surface of composites BNDCC 3,13 samples with D25 W1 and Ba23 bis grinding wheels with working

/mm⋅s after

)

**The microscopic image of BNDCC composite** 

sharply defined edges with blunted of blade grains in carbide matrix.

a)

b)

established through their mechanical treatment after sintering. Microscope image of the samples after grinding showed

Figure 20. The results of the surface roughness of the composite BNDCC polished 1.47 grinding D25 Ba23: a) before grinding, b) after grinding

Figure 21. Microscope image of composite BNDCC: a) before; b) after the treatment grinding D46 Ba23 bis binder **Figure 21.** Microscope image of composite BNDCC: a) before; b) after the treatment grinding D46 Ba23 bis binder

#### *2.2.5. The mathematical model of the function of research object*

The mathematical model describing the change in the surface roughness Ra of the treated object as a function of the depth of grinding and peripheral speed of grinding wheel was shown in graphic form (fig. 22, 23). The function of the object of research was determined for the grinding process of D46 Ba23 bis wheel and D25W1 wheel BNDCC composite of grit size 4-8 m assuming independent parameters (depth of grinding, ae and grinding wheel peripheral speed vs) and the dependent parameter (surface roughness of the composite). For DOE purposes and analysis of experimental results, STATISTICA was used [15,16]. The range of variability was low. Statistical analysis of the results of experimental studies included

**•** Approximation of object function tests,

**The mathematical model of the function of research object** 


The function of the object of research adopted in the form of a polynomial of the second degree of interaction is described by the following formula:

> for D25 Ba23 bis *y* = 0, 15 – 7, 76 ae– 0, 01 V*<sup>S</sup>* + 0, 27 a*<sup>e</sup>* V*<sup>S</sup>* for D25 W1: *y* = 0, 014 – 1, 6 a*<sup>e</sup>* – 0, 02 V*<sup>S</sup>* + 0, 18 a*e*V*<sup>S</sup>* \

where:

ae, vs – the size of the input,

a0 ÷ a5– polynomial coefficients.

The results of preliminary calculations showed that the best fit regression equations to the results of the experiment allows the second degree polynomial model of interaction, and therefore the calculated regression equation stepwise regression presented in this form. Analysis of individual regression equations fit to the experimental results was based on multivariate correlation coefficient R and also based on function values and Student's t-value of F-Snedecor. The level of significance p = 0.05.

a)

b)

**The microscopic image of BNDCC composite** 

72 Sintering Techniques of Materials

sharply defined edges with blunted of blade grains in carbide matrix.

**The mathematical model of the function of research object** 

**•** Approximation of object function tests,

where:

ae, vs – the size of the input, a0 ÷ a5– polynomial coefficients.

of interaction is described by the following formula:

a) b)

*2.2.5. The mathematical model of the function of research object*

low. Statistical analysis of the results of experimental studies included

**•** Statistical verification of the adequacy of the function approximating,

for D25 Ba23 bis

for D25 W1:

**•** Statistical verification of significance approximating function coefficients.

Figure 20. The results of the surface roughness of the composite BNDCC polished 1.47 grinding D25 Ba23: a) before grinding, b) after grinding

The samples of BNDCC composites were observed under a scanning microscope before and after the grinding tests. For all composite samples before grinding process parallel scratches were visible on the surface of the samples. These were probably established through their mechanical treatment after sintering. Microscope image of the samples after grinding showed

Figure 21. Microscope image of composite BNDCC: a) before; b) after the treatment grinding D46 Ba23 bis binder

The mathematical model describing the change in the surface roughness Ra of the treated object as a function of the depth of grinding and peripheral speed of grinding wheel was shown in graphic form (fig. 22, 23). The function of the object of research was determined for the grinding process of D46 Ba23 bis wheel and D25W1 wheel BNDCC composite of grit size 4-8 m assuming independent parameters (depth of grinding, ae and grinding wheel peripheral speed vs) and the dependent parameter (surface roughness of the composite). For DOE purposes and analysis of experimental results, STATISTICA was used [15,16]. The range of variability was

The function of the object of research adopted in the form of a polynomial of the second degree

*y* = 0, 15 – 7, 76 ae– 0, 01 V*<sup>S</sup>* + 0, 27 a*<sup>e</sup>* V*<sup>S</sup>*

*y* = 0, 014 – 1, 6 a*<sup>e</sup>* – 0, 02 V*<sup>S</sup>* + 0, 18 a*e*V*<sup>S</sup>* \

The results of preliminary calculations showed that the best fit regression equations to the results of the experiment allows the second degree polynomial model of interaction, and

**Figure 21.** Microscope image of composite BNDCC: a) before; b) after the treatment grinding D46 Ba23 bis binder

**Figure 22.** The influence of processing parameters on the surface roughness of the composite samples BNDCC polish‐ ed by grinding wheel D46 with Ba23 bis

**Figure 23.** The influence of processing parameters on the surface roughness of the composite samples BNDCC polish‐ ed by grinding wheel D46 with W1 binder

Analysis of relationship shown in Figure 22 and 23 confirmed that the minimum value of surface roughness BNDCC samples was obtained at the peripheral speed of grinding wheels in the range 14-16 m/s and 0.005 mm depth of grinding/double stroke of table. These data verified the results of performance tests of these samples.
