性能的影響
(華中科技大學(xué) 材料成型及模具技術(shù)國(guó)家重點(diǎn)實(shí)驗(yàn)室，武漢 430074)
摘 要: 振動(dòng)凝固和Ce-Sb復(fù)合微合金化都能明顯細(xì)化消失模鑄造AZ91D鎂合金的鑄態(tài)組織。經(jīng)振動(dòng)凝固的鑄態(tài)組織特征與原始鑄態(tài)的相差不大，復(fù)合微合金化后的細(xì)化效果更顯著，且經(jīng)Ce-Sb復(fù)合微合金化處理后在α-Mg基體上出現(xiàn)大量彌散分布的顆粒狀CeSb相，在晶內(nèi)和晶界分布著少量的Al11Ce3針狀相。兩種處理工藝都能使消失模AZ91D試樣的抗拉強(qiáng)度和伸長(zhǎng)率得到較大幅度提高，其中經(jīng)Ce-Sb復(fù)合微合金化后的常溫力學(xué)性能提高最大，兩種方法都沒(méi)有使消失模AZ91D試樣的斷裂方式發(fā)生明顯改變，但Ce-Sb復(fù)合微合金化后的合金鑄態(tài)斷口具有明顯的塑性變形特征。
關(guān)鍵字: AZ91D合金；消失模鑄造；振動(dòng)凝固；Ce-Sb合金化
and properties of AZ91D magnesium alloy
via lost foam casting
（State Key Laboratory of Material Processing and Die and Mould Technology,
Huazhong University of Science and Technology, Wuhan 430074, China）
Abstract:Vibration-freezing and adding 1.0%Ce-0.4%Sb can obviously refine the microstructure of lost foam cast AZ91D magnesium alloy. The characteristic of as-cast microstructure has a little difference from that of vibration-freezing. But the microstructure has smaller grain size after addition of microscale cerium and antimony. From SEM photographs of the samples after Sb-Ce alloying, it is found that a large number of granular CeSb phase distributes in the grain, and a little needle Al11Ce3 phase in both grain and boundary. Both the methods can improve the tensile strength and elongation of AZ91D alloy via LFC to a great extent. And the improved value is the largest by addition of Ce and Sb. Although they can’t change the fracture mode of AZ91D alloy, SEM fractographs of tensile fracture surface after Sb-Ce alloying have obvious plastic deformation.
Key words: AZ91D alloy; lost foam casting; vibration-freezing; Ce-Sb alloying
