AZ91D镁合金半固态触变成形压铸工艺  

Die-casting process of semi-solid thixo-forming of AZ91D Mg alloy

作　　者：阎峰云[1] 强旭东[2] 张玉海[1] 黄晓锋[2] 范松岩[1] 

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,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,兰州730050

出　　处：《中国有色金属学报》2008年第4期595-600,共6页The Chinese Journal of Nonferrous Metals

基　　金：国家重点基础研究发展规划资助项目(2007CB613700);甘肃省科技支撑计划资助项目(0708GKCA029)

摘　　要：采用等温热处理对AZ91D镁合金进行非枝晶化,研究半固态镁合金的触变压铸工艺,得到性能良好的触变压铸镁合金试件。通过改变压力和压射速度等工艺参数,发现其抗拉强度和伸长率都随着压力或速度的上升而增加,当增压压力为35 MPa和压射速度为4.5 m/s时,其抗拉强度达到最大,为237.5 MPa,伸长率为4.8%。通过组织分析认为,半固态触变压铸对晶粒细化效果明显,这与固相颗粒在充型过程中的二次破碎,液相喷射分散后凝固具有直接的关系。The non-dendrite or spherical grains microstructure of AZ91D magnesium was obtained using the isothermal treatment technique and the thixo-casting process were studied under semi-solid state. The specimens with good properties were obtained and analyzed. The effects of injection speed and additional pressure on tensile strength, elongation rate and microstmcture of specimens were investigated. The results show that the mechanical properties of alloy can be improved with the increase of injection speed and additional pressure. While the additional pressure is 35 MPa and the injection speed is 4.5 m/s, the tensile strength and elongation rate can reach 237.5 MPa and 4.8%, respectively. Through the microstructure analysis, the semi-sofid thixo-casfing most obviously refines the crystal grain. The solid phase particles in the semi-solid ingot may be broken into pieces again and the liquid phase may be sprayed and solidified during filling process due to most high shearing strength.

关 键 词：镁合金 触变成形 半固态压铸 等温处理 力学性能 

分 类 号：TG146.22[一般工业技术—材料科学与工程]