Acta Metallurgica Sinica (English Letters) ›› 2013, Vol. 26 ›› Issue (4): 473-482.DOI: 10.1007/s40195-012-0176-3

Previous Articles     Next Articles

Microstructure in the Semi-solid State and Mechanical Properties of AZ80 Magnesium Alloy Reheated from the As-cast and Extruded States

Wenyong JIANG, Tian CHEN, Liping WANG, Yicheng FENG, Yan ZHU, Kaifeng WANG, Jiapeng LUO, Shouwei ZHANG   

  1. College of Materials Science and Engineering, Harbin University of Science and Technology, Harbin 150040, China
  • Received:2012-10-17 Revised:2013-03-05 Online:2013-08-25 Published:2013-07-11
  • Contact: Tian CHEN
  • Supported by:

    Department of Education of Heilongjiang Province (No. 12511069), Heilongjiang Province Natural Science Foundation (No. QC2010110), Special Fund Project for Scientific and Technological Innovation Talents of Harbin (No. 2012RFQXS113) and Entrepreneurship for Under-graduates (No. 201210214008).

Abstract:

The multi-axial forging (MAF) process was introduced into the strain induced metal activation (SIMA) process to replace conventional forging. Microstructure evolution of MAF formed AZ80 magnesium alloy during partial remelting was investigated. Furthermore, the tensile mechanical properties for AZ80 magnesium alloy thixoextruded from the starting materials treated by MAF were determined. For comparison, as-cast AZ80 magnesium alloy was also thixoextruded. The results show that the SIMA route produced ideal, fine semi-solid microstructure, in which almost completely spheroidal primary solid grains had a little amount of entrapped liquid. The microstructure of the as-cast alloy in the semi-solid state is less spheroidized compared with the MAF alloy under the similar isothermal holding conditions. With prolonged holding time, the size of the solid grain increases and the degree of spheroidization is improved in the MAF formed alloys. However, the solid grain size of the as-cast alloys decreases initially, and then increases with further increasing temperature. The tensile mechanical properties for AZ80 magnesium alloy thixoextruded from the starting material produced by MAF are better than those of AZ80 magnesium alloy thixoextruded from the starting material produced by casting. The ultimate tensile strength, yield strength and elongation of the alloy thixoextruded from the starting material produced by MAF are 314 MPa, 238 MPa and 14%, respectively.

Key words: Magnesium alloy, Microstructure, Mechanical properties, Partial remelting