【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,
论文部分内容阅读
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70 μm,片层间距约为1.6 μm; 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.
其他文献
The dry sliding wear and friction behaviors of compacted graphite cast iron (C. G. iron) were analyzed. The influence of the operating conditions (i.e. velocity
In-situ titanium matrix composites with N content of 0. 045-0. 27 wt% have been produced by a casting method. The microstructure and mechanical properties of as
Although the coding modes of H. 264 coded video would be changed by the transcoding process of spatial resolution reduction, there exists good correlation in pr
Under vacuum, heat transfer in porous corundum shell of investment casting depends on the characteristics of the solid materials and the spatial arrangement of
The DDA-Ⅱ process aimed at manufacture of diesel fuel meeting the Euro-Ⅳ emission standard from inferior diesel feedstock has been developed and tested in pil
A maximally flat FIR filter design method based on explicit formulas combined with simulated annealing and random search was presented. Utilizing the explicit f
Study on rheological properties of gunned refractory is an effective way to optimize the quality of repaired layer and gunning operation. The fluidity of refrac
Studies the design of distributed virtual environments (DVEs) for tele-multi-robotics. The proposed design, incorporating two models (distribution-supported mod
The vane induced strength of secondary flow in terms of dimensionless moment of momentum is maximum in the case of a rectangular vane with a collar at angle of
Fine scalability can provide not only precise rate control for constant bitrate (CBR) traffic, but also accurate quality control for variable bitrate (VBR) traf