本文選題：非平衡凝固 + 異質(zhì)形核　； 參考：《稀有金屬材料與工程》2017年10期

【摘要】：采用真空感應(yīng)熔煉與階梯型銅模噴鑄方式,制備出含SiC異質(zhì)顆粒的AZ91鎂合金非平衡凝固試樣,研究了異質(zhì)顆粒與銅模冷速協(xié)同作用下亞快速凝固合金的組織演化規(guī)律。結(jié)果表明,在銅模相同內(nèi)徑條件下,SiC顆粒的加入可以有效細(xì)化鎂合金的凝固組織。400℃/2 h固溶處理后,晶界處β-Mg_(17)Al_(12)相消失,初生α-Mg晶粒由細(xì)小粒狀分布向多邊形組織發(fā)生轉(zhuǎn)變。由于SiC顆粒對(duì)晶粒長(zhǎng)大的釘扎效應(yīng),固溶處理后原始細(xì)晶組織得以保存,晶粒尺寸分布趨于均勻。隨銅模內(nèi)徑減小,冷卻速度增大,晶粒細(xì)化效果更加明顯。當(dāng)SiC含量為2%,銅模內(nèi)徑為2 mm時(shí),非平衡凝固鎂合金的HV顯微硬度值最高,可達(dá)1.42 GPa,相比鑄態(tài)提高了87%。
[Abstract]:Non-equilibrium solidification samples of AZ91 magnesium alloy containing SiC heterogeneous particles were prepared by vacuum induction smelting and step copper mold spray casting. The microstructure evolution of sub-rapid solidification alloy under the synergistic action of heterogeneous particles and copper die cooling rate was studied. The results show that the addition of sic particles can effectively refine the solidified microstructure of magnesium alloys after solution treatment at 400 鈩，

本文編號(hào)：1986404