Microstructures and properties of reciprocating extruded
as-cast ZK60 magnesium alloy
as-cast ZK60 magnesium alloy
(1. Northwest Institute For Non-ferrous Metal Research, Xi’an 710016, China;
2. School of Materials Science and Engineering, Xi’an University of Technology, Xi’an 710048, China)
2. School of Materials Science and Engineering, Xi’an University of Technology, Xi’an 710048, China)
Abstract: As-cast d 50 mm ZK60 magnesium alloys were reciprocating extruded for different passes under (335±5)℃. The microstructures and properties of the alloys were studied under different reciprocating extrusion passes. The results show that, reciprocating extruded microstructures were refined and uniformed effectively, in compared with as-cast condition. For 2 passes, the grain size is about 7 μm. After 4 passes, the grain size is about 6 μm. During reciprocating extrusion, refined as-cast eutectic and reinforcement phases in dispersed particles are uniformly distributed on matrix, and their size is less than 50 nm. The tensile strength, yield strength and the elongation of 4 passes reciprocating extruded as-cast ZK60 magnesium alloy are 311 MPa, 214 MPa and 17.93%, respectively. The thermal expansion coefficient of RE-4-EX-ZK60-CT magnesium alloy is the lowest. More or less extrusion passes can not decrease the value of the thermal expansion coefficient.
Key words: reciprocating extrusion; magnesium alloys; ZK60; dynamic recrystallization