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对Ta及Ta-W合金进行渗碳处理,在表面获得一定厚度的渗碳层,可以有效的提高其使用性能。本文对Ta及Ta-W合金进行真空渗碳处理,利用X射线衍射仪、扫描电镜和金相显微镜研究了不同渗碳时间和渗碳温度对样品渗碳结果的影响规律,分析了合金元素W对Ta-W合金渗碳结果的影响。结果表明:在1300℃下渗碳5h,纯Ta渗碳层表面物相为Ta、TaC及Ta2C三相共存;随着渗碳时间的延长,渗碳层中Ta及Ta2C含量逐渐减少,渗碳10h时,Ta及Ta2C相消失并全部生成TaC相。在本文的渗碳条件下,W不与C原子发生反应生成碳化物,而是仍以溶质原子的形式固溶于晶体内部。在1300℃~1500℃范围内,随渗碳温度升高,渗碳层厚度增加;随着渗碳时间的延长,渗碳层厚度增加;提高渗碳温度有利于TaC相的形成;1500℃下渗碳10h,钽的渗碳层厚度可达35~40μm。在1500℃下渗碳5h,Ta渗碳层厚度约20μm,Ta-2.5%W为10~12μm,Ta-7.5%W渗碳层厚度仅为7~8μm,表明随着钽钨合金中W含量的增加,渗碳速率降低,相同时间内获得的渗碳层厚度越薄。
Carbide treatment of Ta and Ta-W alloy, get a certain thickness of carburized layer on the surface, which can effectively improve its performance. In this paper, the vacuum carburizing treatment of Ta and Ta-W alloys was carried out. The effects of different carburizing time and carburizing temperature on the carburizing results were studied by X-ray diffraction, scanning electron microscopy and metallographic microscope. The effects of alloying elements W Effect of carburizing on Ta-W alloy. The results show that the phases of Ta, TaC and Ta2C coexist on the surface of pure Ta carburized layer after carburizing at 1300 ℃ for 5h. With the extension of carburizing time, the contents of Ta and Ta2C in carburized layer decrease gradually, At 10h, Ta and Ta2C disappeared and all formed TaC phase. In the carburizing conditions of this article, W does not react with C atoms to form carbides, but instead remains dissolved in the crystals as solute atoms. With the increase of carburizing temperature, the thickness of carburized layer increased with the increase of carburizing temperature from 1300 ℃ to 1500 ℃. The thickness of carburized carburized layer increased with the increase of carburization time. The carburization temperature was favorable for the formation of TaC phase. Carburizing 10h, tantalum carburized layer thickness up to 35 ~ 40μm. Carburizing at 1500 ℃ for 5h, the thickness of Ta carburized layer is about 20μm, Ta-2.5% W is 10 ~ 12μm, Ta-7.5% W carburized layer is only 7 ~ 8μm, The carburization rate is reduced, and the carburized layer obtained in the same time is thinner.