摘要
研究了在AZ31变形镁合金熔体凝固过程中施加脉冲磁场对其组织及压缩性能的影响。在设定的浇注温度下,考察了脉冲电压、脉冲频率及模具温度对合金的初生相形貌和晶粒尺寸的影响。结果表明,脉冲磁场可有效细化AZ31镁合金的组织;脉冲电压在0~300V范围内,脉冲频率在1~10Hz时,随着脉冲电压或脉冲频率的增加,合金的平均晶粒尺寸逐渐减小,初生相由发达的树枝晶退化成等轴晶和蔷薇晶。当模具温度在20~600℃时,AZ31镁合金的凝固组织出现先细化后粗化现象,拐点值为200℃;与常规铸造工艺相比,脉冲磁场对合金的压缩性能有明显影响,当脉冲电压为300V,脉冲频率为5Hz,浇注温度为720℃,模具温度为200℃时,合金的抗压强度达到340.87 MPa,抗压强度提高了71.40%,压缩率提高了75.14%。
Effects of pulsed magnetic field on solidification structure and compressive performance of AZ31 alloy were investigated.Morphology of primary phase and grain size in the alloy with different pulsed voltage,pulsed frequency and mould temperature under the conditions of designed temperature were expounded.The results show that solidification structure of AZ31 alloy can be improved significantly by pulsed magnetic field treatment.With the increase of pulsed voltage（0-300 V）,or pulsed frequency（1-10 Hz）,primary phase in the alloy is degraded gradually from well-developed dendrites into fine equiaxed grains or rosette crystals.With mould temperature at 20-600℃,primary grain size is refined firstly and then coarsened.At 200 ℃,grain size presents desirable.Pulsed magnetic field can improve greatly compression performance of AZ31 alloy.With the pulsed voltage of 300 V,pulsed frequency of 5 Hz and pouring temperature of 720 ℃ as well as mould temperature of 200 ℃,the compressive stress of the AZ31 alloy reach 340.87 MPa.Compared with conventional casting,compressive stress and compressibility of the alloy are increased by up to 71.40% and 75.14%,respectively.
作者
胡世平
陈乐平
周全
王俊
Hu Shiping, Chen Leping, Zhou Quan, Wang Jun(School of Aeronautical Manufacturing Engineering, Nanchang Hangkong Universit)
出处
《特种铸造及有色合金》
CAS
CSCD
北大核心
2018年第5期556-559,共4页
Special Casting & Nonferrous Alloys
基金
江西省教育厅科技重点资助项目(GJJ1606796)
关键词
AZ31镁合金
脉冲磁场
凝固组织
压缩性能
AZ31 Magnesium Alloy
Pulsed Magnetic Field
Solidification Structure
Compression Performance
