Influence Of Al And Ca Addition On The Texture And Mechanical Properties Of Mg-Al-Ca-Mn Alloy

Developingmagnesium alloy with low cost, excellent mecanical properties and heat-resistancethat can satisify the automobile transmission system is becoming an important issue.A Ca containing Mg-Al based alloy attracting increaseing attention.In present work, microstructure and mechanical properties of seven kinds of hot extruded magnesium alloy bar, MA10(Mg, Mn, Al), MA11, MX10(Mg, Mn, Ca), MX11, MAX101(Mg, Mn, Al, Ca), MAX110, MAX111 and a hot extruded flat elliptical tube of Mg-1.0t%Al-1.5wt%Ca-1.0wt%Mn.were systematically studied. The effect of Al, Ca and Al, Ca jointly addition on the microstructure and mechanical properties of Mg-AlCa-Mn alloy were addressed. The important results are concluded as follows① In Mg-Al alloy, addition of Al contribute to DRX slightly, while can not refine the grains effectively. Thus, the yield strength can not be enhanced. However, the addtion of Al can increasing the strain hardening performance, leading to much improved ultimate compressive strength. Increasing the Al content from 0.5% to 1% hardly reduces the plasticity. In Mg-Ca system, addtion of Ca can greatly increase the content of DRX grains. Increasing the Ca content can effectively improve the yield strength and enhance the plasticity slightly.②In MAX alloy, increasing the Ca content from 0.5% to 1% can improve the yield strength greatly, while a similar content increasin g of Al hardly enhance the yield strength. The addition of Al and Ca in a range of 0.5%-1% does not pose pronounce infeluce on plasticity, while stimulates the DRX. The extruded rods contain much Ca containing phases, increasing the Ca content further increase the content of seconda phases.③ The flat section and the cruved section in the Flat elliptical tube cotain a strong recrystallized texture. However, the texture components in those two section greatly differ from each other. The cruved section has a alternatively distributed fiber structure with different orientation. The two sections both have quite fine grain. The as-prepared Mg-Al-Ca-Mn tube has a yield strength of 255 MPa, a ultimate tensile strength of 278 MPa and an elongation of 5.1%...