Work

Sintering Kinetics, Mechanical Properties, and Electrical Conductivity of Ti-67 at% Al Targets Fabricated via Spark Plasma Sintering

Year: 2025

Type: article

Abstract: Ti–Al alloys have widespread applications as targets in hard coatings by PVD (Physical Vapor Deposition). While the importance of target density is recognized, the densification mechanisms of Ti-67 at% Al targets, particularly during spark plasma sintering (SPS), remain poorly understood, hindering process optimization. This study aims to clarify these mechanisms by fabricating Ti-67 at% Al targets via SPS and examining their densification behavior through a detailed analysis of the creep model based on the stress exponent (n) and apparent activation energy (Qd). The target’s relative density gradually increased in the temperature range of 370–530 °C, whereas the grain size remained relatively constant, indicating that the densification process dominated during this period. The results reveal that densification is primarily controlled by intergranular diffusion (n ≈ 2, Qd = 97.29 kJ/mol) and dislocation climbing (n ≈ 3, Qd = 158.74 kJ/mol). The target’s relative density reached 98.25% at 530 °C, with a corresponding grain size of 10.86 ± 1.08 μm. Additionally, as the temperature increased, the Vickers hardness of the target increased from 61.56 HV to 129.66 HV, and the electrical conductivity rose from 0.23 S/cm to 0.86 S/cm. This work provides a fundamental understanding of the densification kinetics in Ti-67 at% Al alloys during SPS, establishing a crucial guideline for fabricating high-performance PVD targets.

Source: Coatings

DOI: 10.3390/coatings15091029