钛合金粉末注射成形溶剂脱脂工艺研究

Research on Solvent Debinding Process of Titanium Alloy Compacts by Metal Injection Molding

采用粉末注射成形方法制备了钛合金坯体,然后利用溶剂脱脂方法脱除坯体中可溶性粘结剂。通过对溶剂脱脂动力学分析表明,在脱脂过程中,存在动力学控制步骤转化的过程,提出了脱脂临界厚度的概念。当厚度超过5mm时,试样脱脂过程受扩散控制,在常温下进行溶剂脱脂时,其扩散系数为1.86×10-6cm2.s-1,活化能为12.96kJ.mol-1.K-1;在厚度小于5mm时,试样脱脂过程受粘结剂溶解和扩散混合控制。

Titanium alloy compacts were prepared by metal injection molding. Solvent debinding process could remove dissoluble binder in the compacts. By analyzing the kinetics of the solvent debinding, shifting of different controlling mechanism was found in the debinding process. The definition of critical thickness was put forward. The solvent debinding process was controlled by diffusion for the sample with a thickness of more than 5mm. The diffusion coefficient is 1.83 × 10^-6 cm^2.s^-1 at room temperature and the diffusion active energy is 12.96 kJ.mol^-1.K^-1. When thickness of the samples is less than 5mm, the solvent debinding process is controlled both by diffusion and solvent dissolution of the binder.