摘要
采用扫描示差量热法(DSC)、扫描电镜(SEM)、光学显微镜(OM)和能谱分析(EDS)等手段研究了含微量Zr的Al-Cu-Mg-Ag合金铸态与不同均匀化热处理态的显微组织演化和成分分布,测定了该合金铸态组织中的低熔点共晶相的成分和熔化温度,确定了该合金的均匀化处理制度和过烧温度。结果表明:Al-Cu-Mg-Ag-Zr合金铸态组织晶界上主要的非平衡相为Al2Cu,其熔点为523.52℃。合金经420℃×6h一级均匀化处理后,Al3Zr粒子在基体内二次析出且弥散分布。经515℃×24h二级均匀化处理后,晶界上的非平衡相大部分溶入基体,枝晶偏析基本消除,晶内各元素分布均匀。该合金的最佳均匀化制度为420℃×6h+515℃×24h,均匀化过烧温度为520℃。
An Al-Cu-Mg-Ag alloy with trace Zr addition was prepared. Its microstructe evolution in the as-cast and homogenized alloy was studied by differential scanning calorimetry （DSC）, scanning electrical microscopy （SEM）, optical microscope（OM） and X-ray energy-dispersive analysis （EDS）. The results show that the low-melting-point phase segregating toward grain boundaries is Al2 Cu, with a melting point of 523.52℃ . After homogenizing at 420℃ for 6 h, metastable or equilibrium phase of Al3 Zr finely forms in the matrix. When the alloy is further homogenized at 515℃ for 24h, most of the non-equilibrium phases at the grain boundaries are removed. The optimized homogenization process for the experimental alloy is 420℃× 6h ＋ 515℃×24h and its over-burning point is 520℃.
出处
《材料热处理学报》
EI
CAS
CSCD
北大核心
2009年第3期96-101,共6页
Transactions of Materials and Heat Treatment
基金
国家重点基础研究发展计划资助项目(2005CB623705-04)
