高能球磨法制备Cu-10%Sn合金的组织结构与烧结性能

Microstructure and Sintering Properties of Cu-10%Sn Alloy Prepared by High-Energy Ball Milling

采用高能球磨法制备Cu-10%Sn合金粉体,然后压制成型并烧结成块体材料。运用XRD、SEM等方法研究Cu-10%Sn合金在高能球磨和烧结过程中的组织结构与性能变化。结果表明:在球磨初期,Sn与Cu原子会结合为亚稳定相Cu_(6)Sn_(5),但随着球磨时间的延长Cu_(6)Sn_(5)又会发生分解,分解出来的Sn将固溶到Cu晶格内。经40 h高能球磨,Cu-10%Sn合金粉体形成了结构稳定的单一的过饱和固溶体,同时从大块的厚片状结构转变成为细小均匀、表面光整的颗粒状结构,平均粒径为30μm,合金中Cu的晶粒尺寸约为26 nm,且Sn和Cu元素呈高度弥散分布状态。该球磨粉体制成的块体材料在750℃下烧结时具有较好的综合性能:粉末颗粒之间形成的冶金结合较好,块体试样尺寸基本稳定,开孔率合理,显微硬度相对较高。

The Cu-10%Sn alloy powder is prepared by high-energy ball milling,and then it is cold pressed and sintered into bulk material.XRD and SEM are used to analyze the microstructure and property evolutions of the Cu-10%Sn alloy during ball milling and sintering.The results indicate that Sn and Cu atoms combine to form a metastable Cu_(6)Sn_(5) phase in the early stage of ball milling.The Cu_(6)Sn_(5) decomposes again with the extension of ball milling time,and the decomposed Sn will be dissolved into the Cu lattice.After being milled for 40 h,the Cu-10%Sn alloy powders form a single supersaturated solid solution with stable structure,and it transforms from a large thick lamellar structure to a fine,uniform and smooth surfaced granular structure.The average particle size is 30 μm,the grain size is about 26 nm,and the Sn and Cu elements are highly dispersed.The bulk material made from this ball milled powders has good comprehensive properties when sintered at 750 ℃.The metallurgical bonding between the powder particles is good,the bulk sample is basically stable,the open porosity is reasonable,and the microhardness is relatively high.