Mechanical and Microstructural Properties of Ultra-fine Grained AZ91Magnesium Alloy Tubes Processed via Multi Pass Tubular Channel Angular Pressing(TCAP)  

作　　者：G.Faraji P.Yavari S.Aghdamifar M.Mosavi Mashhadi 

机构地区：[1]Department of Mechanical Engineering,University College of Engineering,University of Tehran [2]Department of Mechanical and Aerospace Engineering,Science and Research Branch,Islamic Azad University

出　　处：《Journal of Materials Science & Technology》2014年第2期134-138,共5页材料科学技术（英文版）

基　　金：financially supported by Iran National Science Foundation(INSF)

摘　　要：Ultra-fine grained （UFG） cylindrical tubes were produced via recently developed tubular channel angular pressing （TCAP） process through different passes from as-cast AZ91 magnesium alloy. The microstructure and mechanical properties of processed tube through one to four passes of TCAP process at 200℃ were investigated. Microhardness of the processed tube was increased to 98.5 HV after one pass from an initial value of 67 Hr. An increase in the number of passes from one to higher number of passes has no more effect on the microhardness. Yield and ultimate strengths were increased by 4.3 and 1.4 times compared to those in as-cast condition. Notable increase in the strength was achieved after one pass of TCAP while higher number of passes has no more effect. Microstructural investigation shows notable decrease in the grain size to around 500 nm from the primary value of - 150 μm. Dissolution and distribution of hard MglTAI12 phase in the grain boundaries of dynamically recrystallized UFG AZ91 with a mean grain size of - 500 nm was an interesting issue of TCAP processing at 200 ℃ compared to other severe plastic deformation processes.Ultra-fine grained （UFG） cylindrical tubes were produced via recently developed tubular channel angular pressing （TCAP） process through different passes from as-cast AZ91 magnesium alloy. The microstructure and mechanical properties of processed tube through one to four passes of TCAP process at 200℃ were investigated. Microhardness of the processed tube was increased to 98.5 HV after one pass from an initial value of 67 Hr. An increase in the number of passes from one to higher number of passes has no more effect on the microhardness. Yield and ultimate strengths were increased by 4.3 and 1.4 times compared to those in as-cast condition. Notable increase in the strength was achieved after one pass of TCAP while higher number of passes has no more effect. Microstructural investigation shows notable decrease in the grain size to around 500 nm from the primary value of - 150 μm. Dissolution and distribution of hard MglTAI12 phase in the grain boundaries of dynamically recrystallized UFG AZ91 with a mean grain size of - 500 nm was an interesting issue of TCAP processing at 200 ℃ compared to other severe plastic deformation processes.

关 键 词：Severe plastic deformation Tubular channel angular pressing AZ91 Grain refinement Mechanical behaviour 

分 类 号：TG306[金属学及工艺—金属压力加工]