水基粘结剂3DP法三维打印多孔316L不锈钢的研究

Study on Three-dimensional Printing of Porous 316L Stainless Steel by 3DP Method with Water-based Binder

在316L不锈钢粉末中混入粘性粉末聚乙烯醇(PVA)和淀粉,向混合粉末喷射水基溶液,采用3DP法三维打印技术制备出生坯;并进行真空脱粘和烧结,然后获得了多孔不锈钢打印制件。研究了混合粉末中PVA含量及烧结温度对打印制件尺寸收缩、孔隙率、力学性能、拉伸断口形貌和碳含量的影响。结果表明,随着PVA含量的增加,打印制件的收缩率、孔隙率和碳含量均增加,而力学性能不是简单地递增或递减;随着烧结温度的升高,打印制件的收缩率、力学性能均增大,孔隙率降低,碳含量减少,拉伸断口形貌呈现出粉末颗粒冶金结合更紧密的现象。最后将打印制件的性能与块体022Cr17Ni12Mo2(316L)不锈钢、医用植入材料所要求的相应参数值进行了比较。

The two sticky powders of Polyvinyl Alcohol(PVA) and starch were mixed with 316L stainless steel powder,and a water-based solution was jetted to the mixed powder, then the green bodies were fabricated by 3DP method of 3D printing technology. After being debonded and sintered in vacuum, the printed parts of porous stainless steel were obtained.The effects of PVA content in the mixed powder and sintering temperature on the dimensional shrinkage, porosity, mechanical properties, tensile fracture morphology and carbon content of the printed parts were studied. The results show that with the PVA content increasing, the shrinkage, porosity and carbon content of the printed parts increase, while the mechanical properties don’t simply increase or decrease. With the sintering temperature increasing, the shrinkage and mechanical properties increase, the porosity and carbon content decrease. The morphology of tensile fracture shows the metallurgical bonding of powder particles getting more compact. At last, the properties of the printed parts are compared with the corresponding required parameters of bulk stainless steel 022Cr17Ni12Mo2(316L) and the medical implant materials.