【摘要】 在ZA27合金熔体中导入超声波搅拌能够获得成分均匀、晶粒细小的半固态ZA27合金浆料,本文研究了超声波开始导入时的熔体温度(即熔体过热度)和搅拌时间对ZA27合金初生相尺寸、形貌和分布形态的影响。结果表明,随着超声波开始导入时熔体过热度的增加,初生相的细化效果大幅度地降低;随着超声波搅拌时间的增加,会得到一个初生相最细小、圆整、分布最均匀的时间点,随后随搅拌时间的延长,初生相晶粒会出现聚集、长大;超声波搅拌能减少晶粒的聚集,使其分布更均匀。更多还原

【Abstract】 The semi-solid ZA27 alloy which of the refined and well-distributed grain can be obtained by stirring with ultrasonic installing.The effects of starting temperature of ultrasonic application (i.e.Melt Superheating) and application time of ultrasonic stirring on microstructure of ZA27 alloy were investigated.The result revealed that the grain size tends to be increased with increasing the starting temperature of ultrasonic application.And there is an appropriate application time of ultrasonic stirring that the grain is to be better refined and distributed.Then when the time is more long,primary α-Al phase is easy to get together and grow much large.And also the application of ultrasonic stirring can decrease the tends of the earlier crystals’ getting together and can make the grain well-distributed.更多还原