液固铸造4343/3003/4343铝合金复合锭的界面组织

采用液固铸造法制备4343/3003/4343铝合金复合锭,研究了复合锭的界面组织、元素分布和界面结合强度,分析了复合锭的界面结合机理。结果表明：在725-750℃浇注4343铝合金,复合锭的界面冶金结合良好,复合界面清晰平直。复合界面由Al-Si固溶体层和Si,Mn元素扩散层构成,Al-Si固溶体层厚薄均匀,Mn,Si元素的扩散距离分别为10μm和32μm,复合界面的结合强度高于3003铝合金的抗拉强度。液固铸造4343/3003/4343铝合金复合锭的界面复合机理为：4343铝合金熔体首先在3003铝合金锭表面急冷形成Al-Si固溶体,Al-Si固溶体中的Si和3003铝合金中的Mn相互扩散,形成牢固冶金结合的复合锭。

Microstructure evolution of 3003/4004 clad ingots under diverse physical fields

In order to improve the quality of clad ingots, diverse physical fields including electromagnetic stirring, power ultrasonic and compound field of ultrasonic and electromagnetic stirring were attempted to prepare clad ingots of 3003/4004 alloys. The solidification structures near the interface in clad ingots were investigated. The experiment results indicate that the solidification structure of 4004 alloy changes from dendritic crystals to petal-like grains when the clad ingot is treated by electromagnetic stirring. With the effect of power ultrasonic, the solidified microstructure of 4004 alloy exhibits the refinement of both primary a（A1） and eutectic silicon. Under the compound field, the primary a（A1） is refined, the morphology of eutectic silicon has a transition from a coarse plate-like form without treatment or thin acicular-like form with power ultrasonic to fine coral-like form.

Direct-chill semi-continuous casting process of three-layer composite ingot of 4045/3004/4045 aluminum alloys

Three-layer composite ingot of 4045/3004/4045 aluminum alloys was prepared by direct-chill semi-continuous casting process,the temperature field distribution near the composite interface,macro-morphology,microstructure and composition distribution of the composite interface were investigated.The results show that semi-solid layer with a certain thickness forms near the interface due to the effect of cooling plate,which ensures successful implementation of casting the composite ingot.Two different aluminum alloys are well bonded metallurgically.The mechanical properties of composite interface were measured,the tensile and shearing strengths of composite interface are 105 and 88 MPa,respectively,which proves that the composite interface is a kind of metallurgical bonding.

浇注温度对液固铸造复合铝锭界面组织与强度的影响

采用液固铸造法制备4343／3003／4343复合锭，研究了浇注温度对复合锭的界面组织和结合强度的影响，讨论了复合锭的界面结合机理。结果表明，在725～750℃下浇注4343／3003／4343复合锭，复合锭的复合界面表现为冶金结合，由Al-Si固溶体层和Si、Mn元素扩散层构成，Al-Si固溶体层厚薄均匀，Si、Mn元素的扩散距离分别为10μm 和32μm，复合界面的结合强度高于3003铝合金的抗拉强度。液固铸造4343／3003／4343铝合金复合锭的界面复合机理为：4343铝合金熔体首先在3003铝合金复合锭表面急冷形成Al-Si固溶体，Al-Si固溶体中的Si和3003铝合金中的 Mn再相互扩散，形成冶金结合。