Post-treatment Process of Semi-solid Powder Rolling
来源期刊：Acta Metallurgica Sinica2015年第10期
论文作者：Xia Luo Yun-Zhong Liu Bin Wang
文章页码：1305 - 1315
摘 要：Semi-solid powder rolling is a strip manufacturing process, which combines powder rolling with semi-solid rolling in one step to prepare high-performance metallic strips. A total of 7050 aluminum alloy strips were prepared by semi-solid powder rolling and then used to study the post-treatment process and evaluate qualities of post-treated strips.Three post-treatment processes involving sintering, pre-sintering—cold deformation—sintering, and hot rolling were used to process the semi-solid powder rolled strips. The results show that both swelling of pores and densification occur during solid-state sintering while microhardness increases. The decrease in density is due to that the swelling of pores has a larger effect on the density change than that of densification. The relative density reaches 92.6% with the maximum microhardness of 300 HV after ‘‘pre-sintering—cold deformation—sintering’’ process. High microhardness is due to the ultrafine secondary particles uniformly distributed within the grains. The microhardness and relative density of a hot rolled strip are 176 HV and 99%, respectively, and the secondary particles disappear. Occurrence of recrystallization in these three post-treatment processes makes the grains finer.
Xia Luo1,2，Yun-Zhong Liu1，Bin Wang2
1. National Engineering Research Center of Near-Net-Shape Forming for Metallic Materials, South China University of Technology2. School of Materials Science and Engineering, Southwest Petroleum University
摘 要：Semi-solid powder rolling is a strip manufacturing process, which combines powder rolling with semi-solid rolling in one step to prepare high-performance metallic strips. A total of 7050 aluminum alloy strips were prepared by semi-solid powder rolling and then used to study the post-treatment process and evaluate qualities of post-treated strips.Three post-treatment processes involving sintering, pre-sintering—cold deformation—sintering, and hot rolling were used to process the semi-solid powder rolled strips. The results show that both swelling of pores and densification occur during solid-state sintering while microhardness increases. The decrease in density is due to that the swelling of pores has a larger effect on the density change than that of densification. The relative density reaches 92.6% with the maximum microhardness of 300 HV after ‘‘pre-sintering—cold deformation—sintering’’ process. High microhardness is due to the ultrafine secondary particles uniformly distributed within the grains. The microhardness and relative density of a hot rolled strip are 176 HV and 99%, respectively, and the secondary particles disappear. Occurrence of recrystallization in these three post-treatment processes makes the grains finer.
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