摘要
采用机械球磨法制备了超细纳米晶AZ31合金,研究了球磨时间和包套温挤压温度对AZ31合金粉末形貌、颗粒尺寸、晶粒尺寸和力学性能的影响,并分析了球磨时间的作用机理。结果表明,机械球磨后的混合粉末的平均颗粒尺寸都要小于未经过机械球磨的原料粉末,且随着机械球磨时间的延长,粉末的平均颗粒尺寸减小;球磨80 h、250℃包套挤压后AZ31合金棒材中的晶粒大小分布较为均匀,平均晶粒尺寸约为200 nm;在相同的包套挤压温度下,随着机械球磨时间的延长,AZ31合金的显微硬度都有逐渐增加的趋势;在相同的机械球磨时间下,随着包套挤压温度的升高,AZ31合金的显微硬度逐渐降低。随着机械球磨时间的延长,AZ31合金的室温屈服强度有所增加,在机械球磨时间为80 h时取得最大值453 MPa。
Ultrafine nanocrystalline AZ31 alloy was prepared by mechanical ball milling method, the effect of milling time and sheath extrusion temperature on the powder morphology, particle size, grain size and mechanical properties of AZ31 alloy were studied, and the mechanism of milling was analysis. The results show that the average particle size of powders after mechanical milling are smaller than the raw material powder without mechanical milling, and with the increase of milling time, the average particle size of powder decreases; the grain size distribution of AZ31 alloy is more uniform after milling for 80 h and extrusion at 250 ℃, the average grain size is about 200 nm; under the same extrusion temperature,with the increase of milling time, the microhardness of AZ31 alloy increases gradually; under the same milling time, with the increase of sheath extrusion temperature, the microhardness of AZ31 alloy decreases gradually. With the increase of the mechanical milling time, the room temperature yield strength of AZ31 alloy increases, and the maximum value（453 MPa）can be obtained when the milling time is 80 h.
出处
《铸造技术》
北大核心
2017年第5期1135-1137,1149,共4页
Foundry Technology
