(中南大学 粉末冶金国家重点实验室，长沙 410083)
摘 要: 基于加压烧结粘弹性流动理论，引入烧结速率不匹配造成的界面应力，并考虑界面应力分布情况，建立两种材料共烧结致密化模型，描述共烧结界面应力对共烧结致密化的影响。通过两种材料自由烧结数据，进行材料参数拟合；通过拟合得到的材料参数进行共烧结致密化模型模拟。结果表明：共烧结会使得试样中存在密度梯度，并且可能加大或者缩小界面处密度差异，对共烧结后界面结合强度造成影响。采用不同孔隙率的铜粉共烧结进行验证，实验测得共烧结试样密度梯度分布以及界面处密度差异变化和模型预测结果一致。
关键字: 共烧结；致密化；烧结理论；密度梯度
（State Key Laboratory of Powder Metallurgy, Central South University, Changsha 410083, China）
Abstract:A model based on viscoelastic theory was established on co-sintering densification. The interface stress caused by mismatch densification rates was modeled and calculated. The interface stress distribution was considered in the model. The model was simulated with the parameters fitted by free sintering of different materials. The results show that the density gradient in co-sintering samples is caused by interface stress, the density difference at co-sintering interface may be enlarged or minimized, and thus has different effects on interface bonding strength. The experimental verification was conducted by using copper powder with different powder loadings. The density gradients and density discrepancy at interface measured in the experiment agree well with the model predictions.
Key words: co-sintering; densification; sintering theory; density gradient
