The grain refinement of the as-cast AZ31 alloys by limestone particles was investigated by grain refining tests and microstructure observations. The results show that the limestone particles have a good grain refining...The grain refinement of the as-cast AZ31 alloys by limestone particles was investigated by grain refining tests and microstructure observations. The results show that the limestone particles have a good grain refining potency, which is deeply related to the addition level of limestone and melting temperature. The optimal addition level and melting temperature are 2.0%（mass fraction） and 720 ℃, respectively. The average grain size of AZ31 alloy is reduced from（556±60） to（236±22） μm. The sound grain refining by raw limestone particles has a good anti-fading capacity without any significant grain coarsening in a 40 min holding time. The concerned grain refining mechanism should be attributed to the inoculated Al-C and Al-C/Al-Mn-（Fe） nuclei. Ultrasonic treatment can enhance the grain refining efficiency of limestone particles through cavitation-enhanced nucleation mechanism.展开更多
基金Project(2016YFB0301104)supported by National Key Research and Development Program of China
文摘The grain refinement of the as-cast AZ31 alloys by limestone particles was investigated by grain refining tests and microstructure observations. The results show that the limestone particles have a good grain refining potency, which is deeply related to the addition level of limestone and melting temperature. The optimal addition level and melting temperature are 2.0%（mass fraction） and 720 ℃, respectively. The average grain size of AZ31 alloy is reduced from（556±60） to（236±22） μm. The sound grain refining by raw limestone particles has a good anti-fading capacity without any significant grain coarsening in a 40 min holding time. The concerned grain refining mechanism should be attributed to the inoculated Al-C and Al-C/Al-Mn-（Fe） nuclei. Ultrasonic treatment can enhance the grain refining efficiency of limestone particles through cavitation-enhanced nucleation mechanism.
