特种铸造及有色合金
特種鑄造及有色閤金
특충주조급유색합금
SPECIAL CASTING & NONFERROUS ALLOYS
2010年
1期
8-11
,共4页
雾化液滴%凝固%临界尺寸%亚稳结构
霧化液滴%凝固%臨界呎吋%亞穩結構
무화액적%응고%림계척촌%아은결구
Atomized Droplets%Solidification%Critical Size%Metastable Structure
将雾化合金液滴的传热与运动方程相耦合,对合金的冷却过程进行研究,探讨液滴尺寸、气体初始速度、熔体过热度等参数对合金冷却过程及粉末微观组织的影响.并结合A390合金进行了计算.结果表明,随着液滴尺寸减小,所获得的冷却速度及过冷度增大;当液滴尺寸足够小时,液滴温度的变化趋势及合金液滴的组织将发生突变;增加雾化气体的初始速度,降低熔体过热度,可以抑制初生相的析出,有利于细化合金的组织.
將霧化閤金液滴的傳熱與運動方程相耦閤,對閤金的冷卻過程進行研究,探討液滴呎吋、氣體初始速度、鎔體過熱度等參數對閤金冷卻過程及粉末微觀組織的影響.併結閤A390閤金進行瞭計算.結果錶明,隨著液滴呎吋減小,所穫得的冷卻速度及過冷度增大;噹液滴呎吋足夠小時,液滴溫度的變化趨勢及閤金液滴的組織將髮生突變;增加霧化氣體的初始速度,降低鎔體過熱度,可以抑製初生相的析齣,有利于細化閤金的組織.
장무화합금액적적전열여운동방정상우합,대합금적냉각과정진행연구,탐토액적척촌、기체초시속도、용체과열도등삼수대합금냉각과정급분말미관조직적영향.병결합A390합금진행료계산.결과표명,수착액적척촌감소,소획득적냉각속도급과랭도증대;당액적척촌족구소시,액적온도적변화추세급합금액적적조직장발생돌변;증가무화기체적초시속도,강저용체과열도,가이억제초생상적석출,유리우세화합금적조직.
The cooling process of the Al-Si alloy were analyzed by a model, in which the heat transfer equation of atomized alloy droplets coupling with motion equation was considered, to understand effects of droplet size, initial gas velocity, super-heat of the melt on cooling process and microstructure of the A390 alloy. It is found that, with decreasing in size of droplet, the obtained cooling rate and under-cooled rate are raised. When the droplet size is decreased to below a critical size, temperature change and microstructure of the droplets are sharply transformed. Precipitation of primary phase can be restrained by increasing initial velocity of atomized gas and decreasing superheating rate of melt, which is beneficial to the refinement of micro-structure of Al-Si alloy.