Vliv tepelného zpracování na mikrostruktury a mechanických vlastnosti slinuté AlCoCrFeNiTi0.5 vysoko entropické slitiny

Effect of heat treatment on microstructure and mechanical properties of spark plasma sintered AlCoCrFeNiTi0.5 high entropy alloy

článek v časopise ve Web of Science, Jimp

en

The present work is focused on synthesis and heat treatment on non-equiatomic AlCoCrFeNiTi0.5 high entropy alloy (HEA) with a composite structure reinforced by TiC nanoparticles. The initial alloy was prepared by mechanical alloying (MA) in a planetary ball mill, compacted by spark plasma sintering (SPS) and heat treated at different temperatures. Mechano-chemical reactions during the MA process as well as the microstructure and hardness of the SPS-ed compacts prior to and after the heat treatment were investigated. During MA, Cr-based supersaturated solid solution with the BCC structure was formed. After SPS at 1100 °C, the BCC solid solution decomposed into nano-grained microstructure consisting of FCC and ordered BCC solid solutions, σ phase, and in-situ formed TiC nanoparticles. The high hardness of the alloy (762 HV) was retained after the subsequent heat treatment at 1100 °C (603 HV). It was shown that the fabrication of TiC reinforced nanocomposites from elemental powders without the use of expensive nanograined powders can be achieved.

Práce je zaměřena na syntézu a tepelného zpracování ne-equiatomické alitiny AlCoCrFeNiTi0.5 TiC nanočásticemi. Prvotní slitina byla připravena mechanickým legováním (MA) v planetární kulový mlýn, kompaktované SPS a tepelně spracované pri různých teplotách. Mechanicko chemická reakce během procesu MA i mikrostruktury a tvrdost SPS-ed kompakty před i po tepelném zpracování byly šetřeny. Během MA vznikol Cr přesycený tuhý roztok s BCC strukturou. Po SPS 1100°C vznikla mikrostruktura skládající se z FCC tuhého roztoku TiC nanočástic. Vysoká tvrdost slitiny (762 HV) byl zachován po následné tepelné zpracování při 1100°C (603 HV).

The present work is focused on synthesis and heat treatment on non-equiatomic AlCoCrFeNiTi0.5 high entropy alloy (HEA) with a composite structure reinforced by TiC nanoparticles. The initial alloy was prepared by mechanical alloying (MA) in a planetary ball mill, compacted by spark plasma sintering (SPS) and heat treated at different temperatures. Mechano-chemical reactions during the MA process as well as the microstructure and hardness of the SPS-ed compacts prior to and after the heat treatment were investigated. During MA, Cr-based supersaturated solid solution with the BCC structure was formed. After SPS at 1100 °C, the BCC solid solution decomposed into nano-grained microstructure consisting of FCC and ordered BCC solid solutions, σ phase, and in-situ formed TiC nanoparticles. The high hardness of the alloy (762 HV) was retained after the subsequent heat treatment at 1100 °C (603 HV). It was shown that the fabrication of TiC reinforced nanocomposites from elemental powders without the use of expensive nanograined powders can be achieved.

Kompozity; slitiny s vysokou entropií ; SPS

Composites; Multi-principal-element alloys alloy; SPS

17.03.2016

ELSEVIER

USA

0167-577X

174

1

53–56

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