TY - JOUR N2 - In this study, different amounts of tantalum carbide (TaC) powders (5, 10 and 15 wt.%) are added to Vanadis 4 Extra steel powders. The composite powders are sintered at 1260, 1280, 1300, 1320, 1340 and 1360°C for 1 h, respectively. The experimental results showed that good mechanical properties (hardness 79.7 HRA, TRS 2246 MPa) were obtained by the addition of 10% TaC sintered at 1320°C for 1 h. Furthermore, the optimal sintered V4ES/TaC (Vanadis 4 Extra steel / TaC) composites after sub-zero treatment possess the highest hardness (80.9 HRA) and transverse rupture strength (TRS) values (2445 MPa), as well as a better polarization resistance (658.99 Ω·cm2). After sub-zero treatment, the VC carbides decompose and re-precipitate refined VC carbides within the grains (VC carbides are formed in steel powder); moreover, the TaC particles are still uniformly distributed around the grain boundaries, which results in dispersion strengthening and precipitation hardening. The results clearly reveal that sub-zero heat treatment effectively improves the microstructure and strengthens the V4ES/TaC composite. L1 - http://www.czasopisma.pan.pl/Content/116030/PDF/AMM-2020-2-07-Chang.pdf L2 - http://www.czasopisma.pan.pl/Content/116030 PY - 2020 IS - No 2 EP - 563 DO - 10.24425/amm.2020.132793 KW - Tantalum carbide KW - Vanadis 4 Extra steel KW - transverse rupture strength KW - polarization resistance KW - sub-zero heat treatment A1 - Huang, Kuo-Tsung A1 - Chang, Shih-Hsien A1 - Chuang, Chan-Yu PB - Institute of Metallurgy and Materials Science of Polish Academy of Sciences PB - Committee of Materials Engineering and Metallurgy of Polish Academy of Sciences VL - vol. 65 DA - 2020.05.08 T1 - Microstructure and Properties of Composite Produced by Vacuum Sintering of Vanadis 4 Extra Steel Powder with Tantalum Carbides and Following Heat Treatment SP - 555 UR - http://www.czasopisma.pan.pl/dlibra/publication/edition/116030 T2 - Archives of Metallurgy and Materials ER -