( 1. 中南大学 粉末冶金国家重点实验室， 长沙 410083;
2. 自贡硬质合金有限责任公司， 自贡 643011)
摘 要: 采用两步法(预烧结-渗碳处理)， 制备出了具有钴相梯度结构的硬质合金。 研究了渗碳处理前合金中η相的形态和含量与合金中碳含量的关系， 讨论了渗碳处理温度以及碳含量对矿用梯度合金梯度结构形成的影响，并对梯度硬质合金的梯度形成机理进行了探讨。 结果表明： 在本实验条件下， 初始碳含量与渗碳温度是影响梯度结构的主要参数； 在其它条件相同的情况下， 初始碳含量越高，梯度结构越明显， 厚度越大； 渗碳温度越高， 梯度结构越不明显。 研究还发现， 上述参数对梯度结构的作用主要是影响碳原子的扩散和液相的流动。
关键字: 粉末冶金； 硬质合金； FGM； 渗碳烧结
（ 1. State Key Laboratory of Powder Metallurgy,Central South University, Changsha 410083, China;
2. Zigong Cemented Carbide Corp Ltd, Zigong 643011, China）
Abstract: Cemented carbide with gradient cobalt structure was fabricated by use of two-step method(presintering-carbusintering). The relationship between the morphology and content of η phase and the carbon content was studied. The influences of the carbusintering temperature and carbon content on the formation of the gradient structure of the cemented carbide for mining were discussed, and the formation mechanism of gradient structure was analyzed. The results show that the carbon content and carbusintering temperature are the main parameters that influence the formation of gradient structure. The higher the carbon content is, the more apparent and the thicker the gradient structure are; the higher the carbusintering temperature is, and the less apparent the gradient structure becomes. The results also show that the parameters above-mentioned influence the formation of the gradient structure by affecting the diffusion of carbon and liquid flow.
Key words: powder metallurgy; cemented carbide; FGM; carbusintering
