【摘要】 采用快速凝固/粉末冶金(RS/PM)法制备了Si增强的AZ91镁合金.研究了不同Si含量对AZ91镁合金的微观组织、室温和高温力学性能的影响.结果表明:随着Si含量的增加,合金中原位生成的Mg2Si颗粒逐渐长大.Si的加入显著提高了合金的室温和高温力学性能.室温下,当Si含量≤3%时,合金的抗拉强度随着Si含量的增加而提高,当Si含量增加至5%时,合金的抗拉强度大幅度降低.其中RS/PM(AZ91+3%Si)合金表现出最优异的室温力学性能:bσ高达472.36 MPa,σ0.2和δ分别达到329.76 MPa和4.70%.合金的高温抗拉强度(473 K)随着Si含量的增加而提高.更多还原

【Abstract】 Si-enhanced AZ91 magnesium alloy was obtained through Rapid Solidification/Powder Metallurgy(RS/PM).The effects of different Si content on the microstructure,the room and elevated temperature mechanical properties of AZ91 alloy were examined.The results show that Mg2Si particles generated in situ grew up gradually as the increasing of Si content.Adding Si to the alloy can significantly improve the room and elevated temperature mechanical properties.At the room temperature,the tensile strength of alloys improved with the Si contents increased when the Si contents less than 3(mass)%.But when the Si contents increased to 5(mass)%,the alloy tensile strength reduced significantly.The alloy with 3(mass)%Si exhibits the best mechanical properties,its 0.2% yield tensile strength,ultimate tensile strength and elongation of rupture were 354.93 MPa,472.36 MPa and 4.70%,respectively.And the alloy elevated temperature(473 K) tensile properties improved as the Si addition increased.更多还原