摘要
铌、硼和钨在TiAl基合金中的存在形式、分布状态与该合金的制备方法、加工工艺及热处理制度有密切的联系,它们对TiAl基合金的性能又有重要影响。为进一步对有关问题进行研究,该文对铌、钨、硼在TiAl基合金中的作用进行了综合分析,对铸造法制得的Ti-Al-Nb-W-B合金进行了热等静压和均匀化处理,并对微观金相组织进行了观察比较。结果表明:Ti-45Al-7Nb合金中添加少量的钨和硼,能使晶团尺寸明显细化,达40μm。随钨含量的增加,晶团尺寸越来越小,片层间距则越来越大,如Ti-45Al-7Nb-0.15B的晶团尺寸约为100μm,片层间距约为1.2μm;Ti-45Al-7Nb-0.2W-0.15B的晶团尺寸约为70μm,片层间距约为1.6μm;Ti-45Al-7Nb-0.4W-0.15B的晶团尺寸约为50μm,片层间距约为1.7μm;Ti-45Al-7Nb-0.7W-0.15B的晶团尺寸约为40μm,片层间距约为1.8μm。钨含量达到0.4%以后,晶团细化及片层间距增加的效果便渐趋稳定。
The existing pattern and the distribulion state of Nb, B, W in TiAl based alloy are tightly correlated with the preparation process and hear treatment system, and all of them have importent influences to the properties of the TiAl based alloy. Thereby for exploring the related question further, the effect of Nb, W and B on microstructure of TiAl based alloy was summarized and analysed; the as-cast Ti-Al-Nb-W-B alloy was hot isostatic pressed（HiPped） and annealed; the microstructures at different states were observed and compared. The results show that： a little addition of W and B can refine the grain size of the alloy to 40 μm. With increasing the content of W, the grain size decreases, but the lamellar spacing increases. The grain size and lamellar spacing of Ti-45Al-7Nb-0.15B, Ti-45Al-7Nb-0.2W-0.15B, Ti-45Al-7Nb-0.4W-0. 15B and Ti-45Al-7Nb-0.7W-0.15B are 100 μm, 1.2 μm; 70μm, 1.6μm; 50 μm, 1.7μm and 40μm, 1.8μm, respectively. While the content of W reaches 0.4%, the grain size and lamellar spacing becomes keeping at a stable value.
出处
《粉末冶金材料科学与工程》
EI
2006年第1期32-37,共6页
Materials Science and Engineering of Powder Metallurgy
