摘要
对铸态Mg-6.0%Zn-1.0%Y-0.6%Ce-0.6%Zr合金采用往复挤压和正挤压相结合的工艺,制备了d 1.55-2.08 mm不同直径、不同表面光洁的细丝材料。选取d 1.75 mm丝材,用OM、SEM和STEM分析材料的组织,用Instron 5500R和弯曲试验装置测试细丝的力学性能。结果表明：细丝晶粒直径为1μm;第一类强化相的平均尺寸为0.5μm;第二类强化相的平均尺寸小于35 nm;第三类强化相的平均尺寸小于10 nm,且为析出相。挤压态细丝的屈服强度、抗拉强度和伸长率分别为237 MPa、297 MPa和12.5%,拉伸模量为115 GPa。经过300℃保温10 min空冷热处理后,材料的屈服强度、抗拉强度和伸长率分别为300 MPa、364 MPa和6%。材料的强度取决于第二和第三类颗粒尺寸与体积分数,而塑性则取决于第一类强化相的形状与尺寸。材料的临界对折压杆直径约为5 mm,压应力是细丝弯曲断裂的控制因素。
The magnesium wires with different diameters from 1.55 mm to 2.08 mm were prepared by reciprocating extrusion and forward extrusion as-cast Mg-6.0%Zn-1.0%Y-0.6%Ce-0.6%Zr.The wires with the diameter of 1.75 mm were analyzed using OM,SEM,STEM,Instron mechanical property equipment and bending tester.The microstructure of the wire consists of fine equiaxed grains with diameter of 1 μm and three different kinds of strengthening particles.The diameter of the first kind particle is 0.5 μm.The diameter of the second kind is less than 35 nm.The diameter of third kind,however,is precipitate forming during hot working.The ultimate tensile strength,tensile strength and elongation of the as-extruded wire are 237 MPa,297 MPa and 12.5%,respectively.After holding at 300 ℃ for 10 min and then cooling in air,the corresponding yield strength,tensile strength and elongation are 300 MPa,364 MPa and 6%,respectively.The modulus of elasticity is 115 GPa.The high strength of the wire is determined by the refined grains,the second and third kinds of strengthening particles.However,the elongation is controlled by the first kind strengthening particles.The critical bending diameter controlled by compressive stress is about 5 mm.
出处
《中国有色金属学报》
EI
CAS
CSCD
北大核心
2011年第2期290-295,共6页
The Chinese Journal of Nonferrous Metals
基金
教育部博士点基金资助项目(20070700003)
河南省科技攻关项目(102102210031)
河南省教育厅自然科学基金资助项目(2010A430008)
关键词
镁合金
往复挤压
丝材
力学性能
magnesium alloy
reciprocating extrusion
wire
mechanical property
