( 1. 中南大學 粉末冶金國家重點實驗室， 長沙 410083;
2. 自貢硬質合金有限責任公司， 自貢 643011)
摘 要: 采用兩步法(預燒結-滲碳處理)， 制備出了具有鈷相梯度結構的硬質合金。 研究了滲碳處理前合金中η相的形態(tài)和含量與合金中碳含量的關系， 討論了滲碳處理溫度以及碳含量對礦用梯度合金梯度結構形成的影響，并對梯度硬質合金的梯度形成機理進行了探討。 結果表明： 在本實驗條件下， 初始碳含量與滲碳溫度是影響梯度結構的主要參數(shù)； 在其它條件相同的情況下， 初始碳含量越高，梯度結構越明顯， 厚度越大； 滲碳溫度越高， 梯度結構越不明顯。 研究還發(fā)現(xiàn)， 上述參數(shù)對梯度結構的作用主要是影響碳原子的擴散和液相的流動。
關鍵字: 粉末冶金； 硬質合金； FGM； 滲碳燒結
（ 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
