烧结颈分布对3D打印覆膜Al2O3零件强度的影响  

Effect of sintered neck distribution on strength of 3D printing coated Al2O3 parts

作　　者：赵枢明 薛铠华 杨通[1] 张雪[1] 姚山 ZHAO Shu-ming;XUE Kai-hua;YANG Tong;ZHANG Xue;YAO Shan(School of Materials Science and Engineering,Dalian University of Technology,Dalian 116024,Liaoning,China)

机构地区：[1]大连理工大学材料科学与工程学院

出　　处：《材料工程》2019年第8期132-140,共9页Journal of Materials Engineering

基　　金：国家高技术研究发展计划(863计划)(2015AA042502)

摘　　要：从烧结颈的尺寸及分布入手,研究覆膜Al2O3粉末的粒径分布对零件强度的影响。使用UV激光对覆膜粉末进行原位加热,在影像测量仪下测量并获得烧结颈束腰直径与颗粒直径之间的关系。建立颗粒堆积模型,将烧结颈分布与颗粒配位点对应,计算得出某一截面上被断开的烧结颈的投影面积比例。结果表明:对于2%(质量分数)树脂含量的覆膜Al2O3粉末,随着颗粒直径从75μm增长至375μm,烧结颈的束腰直径从40μm增长至100μm。而堆积模拟结果显示,随着颗粒直径从75~107μm区间增加至300~375μm区间,烧结颈的投影面积比例从0.2557降低至0.0823,与实验测量的覆膜Al2O3粉末的抗拉强度的趋势一致。将70/100,100/140目的颗粒按照质量比0∶10,1∶9,2∶8,3∶7,4∶6,5∶5,6∶4,7∶3,8∶2,9∶1,10∶0混合后计算,发现投影面积比例从0.1772降低至0.1264,孔隙率从0.4511升高至0.4633。综合考虑抗拉强度及透气性,得出优化结果为两者比例为7∶3时,投影面积比为0.1481,堆积孔隙率为0.4596。The influence of the particle size distribution on the strength of the coated Al 2O 3 parts was studied, through the size and distribution of the sintered neck. The powder was heated in situ by a UV laser, and the relationship between the sintered neck waist diameter and the particle diameter was obtained under an image measuring apparatus. A particle packing model was established, and the distribution of the sintered neck was corresponding to the particle coordination point, then the projected area ratio of the sintered neck that was broken in a certain section was calculated. As for the coated Al 2O 3 powder with the resin content of 2%(mass fraction), the results indicate that the sintered neck waist diameter increases from 40μm to 100μm as the particle diameter increases from 75μm to 375μm. The packing simulation results show that the projected area ratio decreases from 0.2557 to 0.0823, as the particle diameter increases from 75-107μm to 300-375μm, which is consistent with the experimentally measured tensile strength of the coated Al 2O 3 powder. The 70/100, 100/140 mesh powder are mixed to simulate based on the mass ratios of 0∶10, 1∶9, 2∶8, 3∶7, 4∶6, 5∶5, 6∶4, 7∶3, 8∶2, 9∶1, 10∶0. The projected area ratio decreases from 0.1772 to 0.1264 and the porosity increases from 0.4511 to 0.4633. Considering the tensile strength and gas permeability, the optimization result is that the ratio is 7∶3, the projected area ratio is 0.1481 and the porosity is 0.4596.

关 键 词：烧结颈 颗粒堆积 覆膜Al2O3粉末 抗拉强度 3D打印 激光选区烧结 

分 类 号：TB332[一般工业技术—材料科学与工程]