Process optimization and performance of spark plasma sintered Ta-10W alloy

Abstract

Ta-10W alloy has the advantages of excellent high temperature strength, high ductility, good weldability and excellent corrosion resistance, and is widely used in chemical and aerospace fields. At present, the commerical tantalum-tungsten alloy products are mainly prepared by vacuum electron beam melting method, but the processing costs a lot which is attributable to its cumbersome processing process. Compared with it, although the tantalum alloy prepared by powder metallurgy is slightly less plastic, it has higher strength. In this work, Tantalum-tungsten (10 wt% W) mixed powder was used as raw material, and Ta-10W alloy was prepared by spark plasma sintering (SPS) technology, and high-performance Ta-10W alloy was prepared by changing the sintering parameters. The test results indicated that the sample had the best mechanical properties at the sintering process 2 (1900 °C, 40 MPa, 10 min). Its hardness was 434.38 HV_0.2, the yield strength of compression at room temperature was 1370 MPa, and it had a good elongation (44.8 %). Its average friction coefficient was 0.677 and abrasive wear was the dominant wear mechanism. Besides, the Ta-10W alloy prepared by SPS exhibited brittle fractures, and the presence of brittle phases, W phase, Ta₂O₅ and Ta₂C further deteriorated sintered Ta-10W's mechanical properties.