**Figure 18.**

*COF vs. time plot.*


#### **Table 6.**

*Frictional coefficients for substrate and surface alloyed specimens.*


#### **Table 7.**

*Coefficient of friction with hardness of the alloys.*

**91**

*Development of Functionally Gradient Cu-Sn-Ni Alloy Using GTA Heat Source*

remains almost a constant value irrespective of the hardness.

The hardness values and the coefficient of friction of surface alloyed Cu-10Sn

**Figure 19** shows the variation in coefficient of friction with hardness for the Cu-10Sn bronze alloys surface alloyed with Ni. It can be inferred that the COF

Cu-10Sn Bronze alloy was Surface Alloyed with Ni and a functionally graded Cu-Sn-Ni alloy with superior surface hardness and wear resistance was developed. Based on the results of this investigation, the following conclusions are drawn:

• A gradient exists in the Ni concentration profile along the depth direction of

• A gradient exists in the hardness profile along the depth direction of the modi-

• Hardness on the surface can be easily controlled by controlling the Ni concen-

• Addition of Ni is found to be highly effective in increasing the hardness of the parent substrate and reducing the wear rate when compared to the addition of

• The Coefficient of Friction of the Surface Alloyed specimen is found to remain

The author is deeply indebted to Defence Research Development Organization, New Delhi (DRDO) for the financial support provided for conducting this project

• The wear rate was found to decrease with increase in hardness, a finding consistent with Archard's theory and that of the previous studies.

• Refinement in grain structure occurs in the surface alloying process.

• Hardness can be significantly improved by surface alloying with Ni.

the modified layer formed in the surface alloying process.

fied layer formed in the surface alloying process.

tration on the surface of the modified layer.

other alloying elements like Ti, TiC and Cr.

constant irrespective of the hardness.

**Acknowledgements**

• The wear behavior is found to be adhesive in nature.

(Project No: ERIP/ER/1003934/M/01/1345 dated 26 July 2011).

*DOI: http://dx.doi.org/10.5772/intechopen.86315*

bronze alloys are reported in **Table 7**.

**7. Conclusions**

**Figure 19.** *COF variation with hardness.*

*Development of Functionally Gradient Cu-Sn-Ni Alloy Using GTA Heat Source DOI: http://dx.doi.org/10.5772/intechopen.86315*

The hardness values and the coefficient of friction of surface alloyed Cu-10Sn bronze alloys are reported in **Table 7**.

**Figure 19** shows the variation in coefficient of friction with hardness for the Cu-10Sn bronze alloys surface alloyed with Ni. It can be inferred that the COF remains almost a constant value irrespective of the hardness.
