Effects of Shrinkage Porosity on Mechanical Properties of a Sand Cast Mg-Y-RE (WE54) Alloy
The distribution of shrinkage porosities in sand cast Mg-Y-RE (WE54) alloy castings was characterized through density measurement and calculated by Archimedes’s principle.The effect of porosity on mechanical properties of sand cast WE54 alloy was investigated through tensile tests and microstructure observation.It was found that the shrinkage porosities distributed mainly in the middle of the plate where the liquid feeding was quite inconvenient.And the porosities were formed along grain boundaries when secondary phases formed at the end of solidification.Hardness tests showed that the vikers hardness declined linearly with increasing porosity volume fraction.While the tensile strength and nominal yield strength declined exponentially as the porosity volume fraction increased.Microstructure observation showed that the fracture cracks propagated along the grain boundaries where porosities and secondary phases gathering together in as-cast WE54 alloy.The tiny porosities distributed in the secondary phases were observed,which could reduce the tensile strength of cast specimens significantly.The heat treatment strengthening effects were significantly weakened by porosities,and even no heat treatment strengthening effect was detected when the porosity volume fraction was higher than 1%.The microstructure observation also proved that no heat treatment strengthening effect existed in samples containing porosities.
Shrinkage porosity Mechanical property We54 alloy Sand cast
Jilin Li Yuequn Ma Rongshi Chen Wei Ke
State Key Laboratory for Corrosion and Protection, Institute of Metal Research, Chinese Academy of Sciences, 62 Wencui Road, Shenyang 110016, China
国际会议
the Chinese Materials Congress 2012(2012年中国材料大会(CMC2012))
太原
英文
390-397
2012-07-13（万方平台首次上网日期，不代表论文的发表时间）