**1. Introduction**

Titanium nitride (TiN) film is applied as a hard coating in industrial fields, which is prepared by physical vapor deposition (PVD), chemical vapor deposition (CVD), and thermal spraying techniques. Because of the B1 NaCl-type structure, titanium nitride exhibits some intrinsic

© 2016 The Author(s). Licensee InTech. This chapter is distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/3.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited. © 2018 The Author(s). Licensee IntechOpen. This chapter is distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/3.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.

characteristics such as high hardness, high melting point, chemical stability, and wear resistance [1]. For these reasons, TiN is extensively used on cutting blades for longer service life, safe medical instruments, diffusion barrier in semiconductor apparatuses and architectural decoration fields, and so on.

**2. Experimental methods**

pressure.

**2.2. Friction tests**

**2.1. Grit blasting and TiN film prepared**

automatically during the friction test.

**3. Results and discussion**

**3.1. Morphology and roughness**

sand blasting machine (China, JICHAN TECH) using 60# Al<sup>2</sup>

AISI 440c stainless steel was chosen as substrate for sand blasting and TiN film prepared. Before grit blasting, the stainless steel substrate was grinded with emery papers and rinsed with acetone and ethanol to get rid of impurity. Grit blasting was carried by a handheld

Effects of Different Materials on the Tribological Performance of PVD TiN Films under Starved…

JICHAN TECH). After then, the morphology of steel substrate was characterized by a JSM-5600LV scanning electron microscope, which attaches with energy disperse spectrometer.

The hard titanium nitride film was prepared using ion plated technology with Hauzer Flexicoat 1200 coating. The deposition parameters were following: 60 A of arc current, 200 V of bias volt, 400 centigrade degree of steel disks, 100 min of deposition time, and 1.8 Pa of N<sup>2</sup>

Friction tests were conducted to evaluate the tribological properties of hard TiN film covered the grit-blasting steel substrate against four different material ball counterbodies using a ballon-disk tribo-tester under starved lubrication regime. The four different upper balls were made of bearing steel, silicon nitride, alumina, and zirconia, which diameter is 8 mm. And the hardness of bearing steel was lower than those of TiN film and other materials. The diameter of the lower disk covered with TiN film was 24 mm. The surface roughness of the test sample was measured with the Micro-Map surface mapping microscope. The initial average surface roughnesses (Ra) of all the upper balls are less than 0.03 μm, and the roughness of lower disk covered TiN film was 8.2 μm which was much higher than upper balls. Friction tests were carried out in ambient temperature and atmospheric environment for 120 min of duration under 5 N of normal load and sliding speed of 31 m/min. The coefficient of friction was recorded

In order to obtain the starved lubrication regime, the small amount of lubricating oil was injected the surface of lower TiN film-covering disk. The calculated thickness of oil film was lower to 3 μm. After friction tests, all the balls and disks were cleaned with acetone by ultrasonic washer for three times. The typical surface morphologies and chemical compositions of friction tracks in lower disks and wear scars in upper balls were analyzed by scanning elec-

After grit blasting, the substrate surface is nonmetal shiny and matte-like. The surface morphology of as-obtained grit-blasting steel substrate was shown in **Figure 1**. It can be seen that surface roughness of the steel substrate was enlarged obviously than the polished samples.

tron microscopy (SEM), which attached an energy dispersive spectrometer.

O3

particles (diamond 300 μm,

http://dx.doi.org/10.5772/intechopen.75842

103

As one wear-resistant coating, the coefficient of friction and wear rate of TiN films are high under dry friction conditions. Efforts to improve the tribological properties of TiN have included changed deposition parameter and doped chemical elements during the film preparation [2–5], surface treatments, and modifications during film post-processing [6–9].

Surface treatments are applied extensively to improve the mechanical properties and tribological performance of many materials, which contain anodizing and hard anodizing, laser texture, mechanical rough, surface hardening, and so on. Among all the methods, blasting with different particles, as one kind of surface treatment technologies, is an effective low-cost surface-modifying method, which can be used to enhance the mechanical character in biomedical [10], automotive [11, 12], aerospace sectors [13], and other industrial applications [14, 15].

Blasting with different particles can enhance mechanical properties of many materials and protected coatings. Lee found that the shear loads for the Al5052/CFRP composites fabricated with treated Al5052 sheet, of which surface roughness (Ra) values were 1.84 and 4.25 μm, were three and five times higher than that of the composite fabricated by using the untreated sheet with Ra value of 0.73 μm, and the bending stress increased from 200 to 400 MPa [12]. During cold rolling process, weight losses for steel sheets finished by conventional acid pickling was greater than those of steel sheets finished using shot blasting [16]. Shot blasting treatment can improve the steam oxidation resistance of austenitic steel compared with previous report [17]. Abusuilik has investigated the effects of various surface treatments on the properties and performance of the hard coating, and found that material transfer and build-up at the coating surface were higher for the surfaces treated by grinding and shot blasting than those treated by other methods [18]. During the open pore metallic foam core sandwich panels prepared by thermal spraying of a coating, Salavati found that the coating porosity and adhesion strength were determined by the substrate surface roughness, which could be controlled by grit-blasting parameters [14]. Other studies of modified surface in metal substrates and some hard coatings on tribological properties are carried out under fully flood lubrication condition. Nakano investigated the effect of pattern texture by grit-blasting method for their tribological properties [19]. Groove pattern texture suppressed the generation of the hydrodynamic pressure, and the lubricating condition of the tests became boundary lubrication. Because the lubrication film became thicker and the hydrodynamic lubrication region was expanded for dimple pattern texture, the lower friction coefficient was lower than that of groove pattern texture. Additionally, some investigations of modified surface under starved lubrication are carried out in last decade, such as laser texture on steel [20, 21], copper [22], hard coatings [23], and piston ring-cylinder [24].

However, only limited studies can be found in the literature associated with the friction and wear behavior of physical vapor deposited TiN film covered the grit-blasting steel substrate sliding against different materials under starved lubrication regime. This paper was investigated the tribological performance of different friction pairs under starved lubrication regime after grit blasting. And the tribological mechanism for different materials was discussed.
