316L不锈钢粉末注射成形件的烧结致密化行为

为了控制粉末注射成形零件的最终尺寸精度和力学性能,对316L不锈钢粉末注射成形件的烧结致密化行为进行了试验研究,分析了烧结温度和升温速率对试件致密化行为以及烧结件力学性能的影响.试验结果表明,致密化过程始于1080℃左右,主要在1200～1300℃的升温过程中快速进行,致密化速率随着升温速率的升高而升高.烧结件的抗拉强度、抗弯强度以及延伸率,不但取决于致密化程度,而且与微观结构有关.分析表明,将基于扩散控制和强度控制的烧结理论结合,可以有效地解释316L不锈钢粉末的致密化行为,需在现有的烧结模型中考虑强度影响因素,才能更真实地模拟烧结过程.

Behaviors of sintering densification for injection molded components in 316L stainless steel powders

In order to control the dimensional accuracy and mechanical properties of the final sintered components,experiments were carried out to investigate the densification behaviors during the sintering process of injection molded components in 316L stainless steel powders.The effect of sintering temperature and heating rate on the densification and final mechanical properties was investigated.The experimental results show that the densification begins at about 1080 ℃ and then is accomplished at high rate mainly during the heating period from 1200 ℃ to 1300 ℃.The densification rate rises with the increase of heating rate.The tensile strength,bending strength and elongation of the sintered components depend on the densification level and the microstructure of sintered specimen.The analysis shows that the densification behaviors of 316L stainless steel powders can be explained well by combination of the diffusion-controlled and the strength-controlled sintering theory.It is still expected to introduce the influence of in-situ strength into the current sintering models to simulate the sintering process more truthfully.