(中國(guó)兵器科學(xué)研究院 寧波分院，寧波 315103)
摘 要: 通過(guò)金相顯微鏡、差示掃描量熱分析以及顯微硬度測(cè)試等研究固溶溫度和固溶時(shí)間對(duì)擠壓鑄造的ZAlSi12CuMgNi鋁合金的顯微組織和力學(xué)性能變化的影響。結(jié)果發(fā)現(xiàn)：在固溶過(guò)程中，強(qiáng)化相逐漸溶解，共晶Si逐漸細(xì)化、彌散，塊狀初晶Si趨于圓整化；保溫時(shí)間過(guò)長(zhǎng)，細(xì)化后的Si會(huì)發(fā)生聚集、粗化、長(zhǎng)大，塊狀Si圓整度下降以及α(Al)晶粒長(zhǎng)大等現(xiàn)象；隨著固溶溫度的上升，強(qiáng)化相的溶解和Si相的粒化、圓整化的時(shí)間會(huì)縮短，且Si相的細(xì)化程度和彌散程度更高，而Si相粗化和α(Al)晶粒長(zhǎng)大的速度也會(huì)增大；在不同固溶溫度下，α(Al)固溶體的力學(xué)性能隨保溫時(shí)間的延長(zhǎng)而呈現(xiàn)不同形式的下降趨勢(shì)；擠壓鑄造的ZAlSi12CuMgNi鋁合金的最佳固溶處理工藝為525~530 ℃，保溫時(shí)間為2.5~3 h。
關(guān)鍵字: 擠壓鑄造；固溶處理；ZAlSi12CuMgNi鋁合金；顯微組織；力學(xué)性能
（Ningbo Branch, Ordnance Science Institute of China, Ningbo 315103, China）
Abstract:The effects of solution temperature and time on the evolution of microstructures and mechanical properties of squeezing casting ZAlSi12CuMgNi aluminium alloy were analyzed by metallography microscopy, differential scanning calorimetry(DSC) and microhardness tests. The results show that the intermetallic phases dissolve and the Si phases are fine, spheroidized and disperse gradually. The fine Si phases congregate, coarsen and grow when the solution time is too long. The coarsening velocity of Si phases will rise, and the time of intermetallic phases dissolved and Si phases spheroidized will be shorter with the increase of solution temperature, in addition, the degrees of dispersal and spheroidization of Si phases become greater. The mechanical properties of α(Al) solid solution show different formats with the solution prolonging at different solution temperatures. The best solution treatment is solution-treated at 525−530 ℃ for 2.5−3 h.
Key words: squeezing casting; solution treatment; ZAlSi12CuMgNi aluminium alloy; microstructure; mechanical property
