快速凝固粉末冶金Mg_(80)Cu_(10)Y_(10)合金的组织与力学性能

采用快速凝固粉末冶金技术制备热挤压Mg_(80)Cu_(10)Y_(10)合金棒材,研究了快速凝固Mg_(80)Cu_(10)Y_(10)合金薄带及热挤压后合金的相结构,并对热处理工艺对合金棒材组织结构及力学性能的影响进行了分析.研究表明,采用单辊快速凝固法在辊速为1800 r/min下制备的Mg_(80)Cu_(10)Y_(10)合金薄带为完全非晶态;在热挤压过程中Mg_(80)Cu_(10)Y_(10)合金中有Mg_2Cu和Mg晶体相析出,其显微硬度比薄带有所提高,这与合金中细小Mg_2Cu颗粒的弥散析出有关;在450 ℃保温4 h后的热挤压Mg_(80)Cu_(10)Y_(10)合金中没有新相析出;随着热处理温度的升高或保温时间的延长,由于Mg_2Cu颗粒出现重溶及聚集长大现象,使得热挤压Mg_(80)Cu_(10)Y_(10)合金的显微硬度表现出逐渐下降的变化趋势.

Microstructure and mechanical properties of rapidly solidified powder metallurgy Mg_(80)Cu_(10)Y_(10) alloy

Hot extruded Mg_(80)Cu_(10)Y_(10) alloy rods were prepared by rapidly solidified（RS）powder metallurgy processing.The phase structure of RS ribbon and as-extruded material was investigated.And influences of the heat treatment process parameters on microstructure and mechanical properties of the alloy bars were analyzed.The results show that rapidly solidified Mg_(80)Cu_(10)Y_(10) alloy ribbon is fully amorphous.Mg_2Cu and Mg crystalline phases precipitate during the consolidation process by hot extrusion,compared with RS ribbon,microhardness of the hot extruded Mg_(80)Cu_(10)Y_(10) alloy is improved which seems to be originated from the dispersed precipitation of fine Mg_2 Cu particles.No new phase is detected in the hot extruded Mg_(80)Cu_(10)Y_(10) alloy for 4 h at 450 ℃.The microhardness of as-extruded Mg_(80)Cu_(10)Y_(10) alloy decreases with increasing the heat treatment temperature or time because of re-melt and growth of Mg_2Cu crystalline particles.