Surface and Tribological Properties of Powder Metallurgical Cp-Ti Titanium Alloy Modified by Shot Peening

Abstract

The present study reveals for the first time the dry sliding wear behavior of a powder metallurgical pure titanium alloy (Cp-Ti) modified by shot peening. Cp-Ti samples were manufactured via powder metallurgy, and then their surface and subsurface features were modified using a custom-made, fully automated shot-peening system. The texture isotropy rate and the highest orientation angle of the shot-peened samples were 71.5% and 36°, respectively. The Abbott curves of the shot-peened surfaces revealed that the most common areal roughness value was 5.177 μm, with a frequency of 8.1%. Shot-peened surfaces exhibited an ~20% lower wear rate than unpeened surfaces under dry sliding wear, whereas the coefficient of friction was the same for both surfaces. Micro-ploughing, micro-cutting, oxidation, and three-body abrasion wear mechanisms were observed on the shot-peened and unpeened surfaces. High resolution 3D surface topographies of worn unpeened and shot-peened surfaces revealed micro-scratches and inhomogeneities along wear tracks, which are indicative of three-body abrasion mechanisms during contact. In addition, vertical and horizontal microcracks were visible just beneath the wear track, suggesting a clear indication of plastic deformation during contact. The cross-sectional hardness maps of shot-peened samples revealed the formation of a work-hardened surface layer with shot peening, which improved the wear resistance. These findings support that shot peening can be a useful tool to modify the surface and tribological properties of powder metallurgical Cp-Ti alloys.

Scratch and wear resistance of interstitial-free steel subjected to severe shot peening

“…Peening coverage can affect the hardness, residual stress, impact strength, wear behaviour, scratch resistance, and friction properties. 9,10 Peening with more than 750% coverage is considered severe shot peening. 11 Severe shot peening is reported to have higher hardness and grain refinement, significant strain-hardened depth, and higher fatigue properties than conventional shot peening.…”

Effect of Regular Shot Peening and Semi-Random Shot Peening Conditions on Selected Properties of the Surface Layer of Gray Cast Iron

“…The use of shot peening and burnishing makes it possible to increase fatigue strength [1,2]. Their use also makes it possible to increase tribological wear resistance [3] and corrosion resistance [4]. Burnishing and shot peening differ in the way the burnishing element affects the workpiece surface.…”

Surface properties of micro surface patterned Cp-Ti alloy via electrical discharge machining

“…The antibacterial surface qualities of the material play the most essential role in making titanium alloys more suitable for biomedical applications and enhancing their surface properties [2]. Commercially pure titanium (Cp-Ti) is widely used in medical and surgical applications, including bio-implantable bone replacements, owing to its excellent biocompatibility, corrosion resistance, and mechanical properties [3][4][5]. It is frequently employed in dental implants due to its desirable biological characteristics, low Young's modulus, and adequate strength [6].…”

“…It is frequently employed in dental implants due to its desirable biological characteristics, low Young's modulus, and adequate strength [6]. Nevertheless, its wear rate and coefficient of friction (CoF) are comparatively weak, which limits its use to situations in which sliding, fretting, and rolling contact are unavoidable [5][6][7][8][9].…”