Microstructure Evolution in a Fast and Ultrafast Sintered Non-Equiatomic Al/Cu HEA

Metals

Mónica Campos¹  Eduardo Reverte¹  Paula Alvaredo¹  Juan Cornide¹  MiguelA. Lagos² 

[1] Department of Materials Science and Engineering, IAAB, Universidad Carlos III de Madrid, Avda. Universidad 30, 28911 Leganés, Spain;TECNALIA, Basque Research and Technology Alliance (BRTA), Mikeletegi Pasealekua 2, 20009 Donostia-San Sebastián, Spain;

关键词: high entropy alloys;    microstructure;    ordered body-centered cubic (BCC/B2);    Cr–Co–Fe–Ni–Al–Cu;    powder metallurgy;    spark plasma sintering;   

DOI  :  10.3390/met11060848

来源: DOAJ

【 摘 要 】

One of the attractive characteristics of high entropy alloys (HEAs) is the ability to tailor their composition to obtain specific microstructures and properties by adjusting the stoichiometry to obtain a body-centered cubic (BCC) or face-centered cubic (FCC) structure. Thus, in this work, the target composition of an alloy of the FeCrCoNi family has been modified by adjusting the Al/Cu ratio in order to obtain a BCC crystalline structure. However, processing conditions always play a key role in the final microstructure and, therefore, in this work, the microstructure evolution of FeCrCoNiAl_1.8Cu_0.5 HEA sintered by different powder metallurgy (PM) techniques has been investigated. The techniques used range from the conventional PM sintering route, that uses high heating rates and sintering times, going through a fast sintering technique such as spark plasma sintering (SPS) to the novel and promising ultrafast sintering technique electrical resistance sintering (ERS). Results show that the increase in the processing time favours the separation of phases and the segregation of elements, which is reflected in a substantial change in the hardness of the alloy. In conclusion, the ERS technique is presented as a very promising consolidation technique for HEA.

【 授权许可】

Unknown