Bi元素的添加对Al-Cu-Si三元共晶合金双峰结构转变的影响  

The Effect of Bi Element Addition on Bimodal Structure Transformation in Al-Cu-Si Ternary Eutectic Alloy

作　　者：孛海娃[1] 唐玲[1] 王永善[1] BO Haiwa;TANG Ling;WANG Yongshan(School of Materials Science and Engineering,Shaanxi University of Technology,Hanzhong 723003,China)

机构地区：[1]陕西理工大学材料科学与工程学院,陕西汉中723003

出　　处：《有色金属工程》2024年第2期24-31,共8页Nonferrous Metals Engineering

基　　金：陕西省科技厅科研基金项目(2020JM-599)。

摘　　要：为了揭示Bi元素对共晶合金中凝固组织的影响和作用机理,使用重力凝固法制备了Al-Cu-Si-xBi(x=0%、0.01%、0.03%、0.05%、0.07%)三元共晶合金,分析了不同添加量Bi对Al-Cu-Si三元共晶合金凝固的组织特征、相的生长形态特征及相组成等的影响。结果表明:Al-Cu-Si三元共晶合金具有α-Al/θ-Al_(2)Cu二元共晶和α-Al/θ-Al_(2)Cu/β-Si三元共晶的混合双峰共晶结构。未添加Bi时,α-Al/θ-Al_(2)Cu二元共晶呈现典型的辐射状菊花集群形态,α-Al/θ-Al_(2)Cu/β-Si三元共晶中的Si相呈现长针状形态,双峰共晶结构较不均匀。随着Bi的添加,α-Al/θ-Al_(2)Cu二元共晶呈现均匀细小的短片层结构,Si相变为点针状。双峰共晶结构的层片间距的差值也逐渐缩小,当Bi的添加量为0.05%时,变质效果最好,双峰共晶结构最为均匀细小,合金硬度亦最好。To reveal the influence and mechanism of Bi elements with different amount in eutectic phase on the undercooled eutectic solidification structure,Al-Cu-Si-x Bi(x=0%、0.01%、0.03%、0.05%、0.07%)eutectic alloys were prepared via using a gravity solidified method.The effect of Bi on the solidification structure of Al-Cu-Si ternery eutectic alloy was investigated.The results show that the Al-Cu-Si ternary eutectic alloy hasα-Al/θ-Al_(2)Cu binary eutectic andα-Al/θ-Al_(2)Cu/β-Si ternary eutectic.The structure is called a bimodal eutectic structure.When Bi is not added,theα-Al/θ-Al_(2)Cu binary eutectic exhibits a typical radial chrysanthemum cluster morphology,the Si phase inα-Al/θ-Al_(2)Cu/β-Si ternary eutectic exhibits elongated needle like morphology.The bimodal eutectic structure is relatively inhomogeneous.With the addition of Bi,α-Al/θ-Al_(2)Cu binary eutectic exhibits a uniform and fine short layer structure,and the Si phase inα-Al/θ-Al_(2)Cu/β-Si ternary eutectic exhibits dot needle-like morphology.The difference in interlayer spacing of the bimodal eutectic structure gradually decreases.When the amount of Bi added is 0.05%,the modification effect is the optimal,and the bimodal eutectic structure is the most uniform and fine.alloy hardness is optimal.

关 键 词：三元共晶 双峰 成分过冷 共晶集群 层间间距 

分 类 号：TG146[一般工业技术—材料科学与工程]