화학공학소재연구정보센터
Materials Science Forum, Vol.357-3, 471-476, 2001
Equal-channel angular pressing as a production tool for superplastic materials
Equal-channel angular pressing (ECAP) was applied for grain refinement of Al-3%Mg0.2%Fe and Al-3%Mg-0.2%Ti alloys and also for a commercial Al 2024 alloy. The grain sizes of the alloys were reduced to similar to0.3 mum. The stability of the fine-grained structures were examined and it was found that the small grains remained stable up to the temperatures of similar to 250 degreesC for the Al-3%Mg-0.2%Fe and Al-3%Mg-0.2%Ti alloys and similar to 400 degreesC for the Al 2024 alloy. Tensile tests revealed maximum elongations of similar to 370% and similar to 180% in the Al-3%Mg0.2%Fe and Al-3%Mg-0.2%Ti alloys, respectively, at a temperature of 250 degreesC with an initial strain rate of 3.3x10(-4) s(-1). There is some evidence for low temperature superplasticity in the Al-3%Mg-0.2%Fe alloy. A maximum elongation of similar to 460% was attained in the Al 2024 alloy at 400 degreesC with an initial strain rate of 10(-3) s(-1). It is demonstrated that the ECAP can be effective in producing superplastic materials.