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采用常规硬质合金生产工艺制备了YG11C﹑YG20C和MB50A3种WC-Co硬质合金牌号试样,研究了深冷处理对3种硬质合金牌号性能和组织的影响。采用SEM分析深冷后合金的微观组织变化,用X衍射分析合金的钴相转变和晶格常数的变化,对深冷前后的3种合金进行了冲击韧性试验。结果表明:深冷处理对合金的磁力、钴磁、硬度和密度几乎无影响,但是会小幅度提高硬质合金的抗弯强度,同时使合金的冲击韧性提高10%以上,深冷处理后合金的微观组织也无明显变化,深冷处理会促使面心立方Co向密排六方Co的转变,但不会影响面心立方钴的晶格常数。
Three kinds of WC-Co cemented carbide grades of YG11C, YG20C and MB50A were prepared by conventional cemented carbide production process. The effects of cryogenic treatment on the properties and microstructure of the three cemented carbide grades were studied. SEM was used to analyze the microstructure of the alloy after cryogenic cooling. The X-ray diffraction analysis of the cobalt phase transformation and the lattice constant changes of the alloys were carried out. The impact toughness tests were carried out on the three alloys before and after cryogenic treatment. The results show that the cryogenic treatment has almost no effect on the magnetic, cobalt magnetic, hardness and density of the alloy, but it will slightly increase the flexural strength of the cemented carbide while improving the impact toughness of the alloy by more than 10%. Microstructure of the alloy after cryogenic treatment There was also no significant change in the organization. Cryogenic treatment led to the transformation of face-centered cubic Co to hexagonal close-packed Co, but did not affect the lattice constant of face-centered cubic cobalt.