Effect of Gaseous carburizing thermochemical treatment on tribological behavior of Ti–6Al–4V alloy

Abstract

This study, concerns the improvement of the hardness and resistance to wear of the Ti-6Al-4V alloy surface by means of thermochemical treatment, for obtaining coatings on the Ti-6Al-4V alloy gives performance of resistance to wear phenomena. Three-thermochemical treatment time (2h, 4h, and 6h) was chosen for investigation of the effect of such treatment on this alloy. The hardness test under an indentation load of 50 gf with a Vickers pyramidal indenter revealed that the surface hardness is 335 Hv for the untreated samples. On the other hand the hardness reaches approximately 1500 Hv during gas cementation at 930 °C for variable times (2h, 4h, 6h) followed by quenching at 840 °C in an oil medium, which was accompanied by a significant improvement in wear resistance. The characterization of the modified surface layers was made by means of a microscopic analysis and by X-ray diffraction. The case-hardening made it possible to obtain a wear resistance greater than that of the alloy not treated, minimal loss of mass by dry friction and an improvement in roughness as well as a good coefficient of friction.

Overview of Surface Modification Techniques for Titanium Alloys in Modern Material Science: A Comprehensive Analysis

“…Coatings 2024, 14, x FOR PEER REVIEW 26 of 42 thickness and the tribological properties of TC4 alloys improve proportionally with increased treatment durations. Upon examining the comparative graph of the tribological properties in Figure 26 [114], a distinct trend is evident. Alloys subjected to prolonged carburization times demonstrate significantly lower friction coefficients.…”

“…Therefore, longer treatment times typically yield a carburized layer of superior quality. Amar et al [114] observed that the carburized layer's could compromise its mechanical properties. The resultant TiC layer is known for its enhanced hardness and wear resistance, making gas carburizing a vital technique in the surface treatment of titanium alloys.…”

“…Therefore, longer treatment times typically yield a carburized layer of superior quality. Amar et al [114] observed that the carburized layer's The second important factor affecting the quality of the penetrating layer is the treatment time. It is generally believed that the longer the treatment time, the greater the thickness of the carburized layer, and the more carbon atoms there are in the carburized layer.…”

“…Therefore, longer treatment times typically yield a carburized layer of superior quality. Amar et al [114] observed that the carburized layer's thickness and the tribological properties of TC4 alloys improve proportionally with increased treatment durations.…”