石墨不同加入方式对AZ91D组织和力学性能的影响  

Effect of Graphite Adding Ways on the Microstructure and Mechanical Properties of AZ91D Magnesium Alloy

作　　者：马孝斌[1] 阎峰云[1] 那元真[2] 李波[2] 

机构地区：[1]兰州理工大学甘肃省有色金属新材料省部共建国家重点实验室,甘肃兰州730050 [2]兰州理工大学有色金属合金及加工教育部重点实验室,甘肃兰州730050

出　　处：《铸造技术》2008年第12期1699-1702,共4页Foundry Technology

摘　　要：研究石墨不同加入方式对AZ91D细化效果的影响。实验表明,石墨、铝粉、RJ-2熔剂三种混合后加入的细化效果最好,晶粒尺寸由未变质前的446μm降至130μm;抗拉强度提高37%,布氏硬度提高17.5%。这主要是由于RJ-2熔剂在变质时作为反应载体,增加C、Al原子的接触几率和反应速率,使得石墨中C原子的利用率增加,生成的Al4C3质点增多;作为精炼剂,促进了Al4C3质点在熔体的均匀扩散并起到一定的精炼作用。证明了碳变质法的机理是Al4C3质点的异质形核作用。In this investigation, the effect of graphite adding ways on the microstructure and mechanical properties of AZ91D magnesium alloy was studied. The results show that the mixture of graphite, aluminum powder and RJ-2 fluxing agent has the best refining effect, the grain size of AZ91D decreases from 446μm to 130 μm;tensile strength is increased by 37 % and Brinell hardness is increased by 17.5%. The main reason is that RJ-2 fluxing agent is a reaction carrier, it can increase the contact probability and reaction rate between C and AI atom, thus increasing utilization rate of atomic C in graphite and the number of Al4O3 particles produced. As a refining agent, R J-2 fluxing agent promotes the diffusion Al4O3 in the melt and plays some roles in refining. In addition, it is also verified that the modification mechanism is that Al4O3 particles play the role of heterogeneity nucleation.

关 键 词：AZ91D 晶粒细化 石墨 AL4C3 

分 类 号：TG136.1[一般工业技术—材料科学与工程]