Thermomechanical processing effects on the structure and properties of Fe-based SMAs. I. Evolution of phase structure

[摘要] The paper analyses the effects of heat treatment (HT) and mechanical alloying (MA) on the evolution of phase structure of an Fe-Mn-Si-Cr-Ni Shape Memory Alloy (SMA) obtained by powder metallurgy (PM). Using various amounts of mechanically alloyed (MA'ed) powders, namely 0 and 40 vol. %, two groups of specimens with chemical composition Fe-14Mn-6Si-9Cr-5Ni (mass.%) were produced by PM. After blending, pressing, sintering and hot-rolling, each set of samples was subjected to five different heat treatment temperatures 973, 1073, and 1373 K, respectively. Tensile pre-straining tests were performed on all samples, with increasing pre-straining degrees up to 4.5 %, in order to stress-induce(hcp) martensitic phase in the material. Structural analysis was implemented by means of X-ray diffraction and SEM observations. XRD and SEM investigations revealed the formation of thermally induced α'-bcc martensite, besides -hcp, as a particularity of this powder metallurgy, mechanically alloyed, shape memory alloy.

[发布机构] Faculty of Materials Science and Engineering, Gheorghe Asachi Technical University of Iasi, Blvd. Dimitrie Mangeron, 61 A, Iasi; 700050, Romania^1;National Railway Company cFR SA, Regional Branch of Passenger Rail Iasi, Str. Piaa Grii 1, Iai; 700090, Romania^2;Particulate Materials Laboratory, Metallurgical and Materials Engineering Department, Istanbul Technical University, Maslak, Istanbul; 34469, Turkey^3

[效力级别] 材料科学

[关键词] Chemical compositions;Effects of heat treatment;Heat treatment temperature;Mechanically alloyed;Shape memory alloys(SMA);Structure and properties;Thermally induced;Thermo-mechanical processing