Effect of TaC Powder Addition on the Microstructure and Mechanical Properties of Ti–Nb–Mn Alloy via Vacuum Sintering Process

Abstract

This study involved the fabrication of Ti–10Nb–3Mn–_XTaC composites through the vacuum sintering process of powder metallurgy, where different proportions of TaC powders (_X = 1, 2, and 3 mass%) were added. The composites were sintered under vacuum conditions at temperatures of 1225, 1250, 1275, and 1300°C for 1 hour each. The experimental findings indicate that the addition of 2 mass% TaC powders to the Ti–10Nb–3Mn alloys resulted in the optimal mechanical properties when sintered at 1275°C for 1 hour. The specimen exhibited a relative density of 96.24%, a hardness of 67.38 HRA, and achieved values of 1276.63 MPa for TRS (tensile rupture strength) and 40.37 GPa for the flexural modulus. The electron backscatter diffraction (EBSD) results revealed that the TaC facilitated the in-situ formation of TiC during the sintering process, which was uniformly dispersed in the Ti matrix. Additionally, the Ta atoms acted as β-stabilizing elements, forming a solid solution in the Ti matrix and improving both the microstructure and mechanical properties of the Ti alloys.

Fig. 3 Comparison of the mechanical properties of various mass% TaC added to Ti–10Nb–3Mn alloys after sintering at different temperatures for 1 h: (a) hardness, (b) TRS and flexural modulus, respectively.