工艺参数对覆膜砂选区激光烧结成形的影响  

Effects of Process Parameters on the Forming of Coated Sand by Selective Laser Sintering

作　　者：朱佩兰[1] 徐志锋[1] 余欢[1] 梁培[1] 

机构地区：[1]南昌航空大学,江西南昌330063

出　　处：《南昌航空大学学报（自然科学版）》2012年第1期104-108,共5页Journal of Nanchang Hangkong University(Natural Sciences)

基　　金：江西省自然科学基金(2010GZC0159)

摘　　要：设计制备了不同树脂含量的100/200目粒度组成的覆膜砂材料,并对其进行了选区激光烧结成形工艺实验,研究了铺粉层厚、激光功率、扫描速度等工艺参数对覆膜砂烧结成形的影响。实验结果表明,随着铺粉层厚的增加,激光烧结件的抗拉强度明显降低1,00/200目粒度组成的覆膜砂激光烧结的有效铺粉层厚为0.15mm～0.25mm。提高激光功率或降低扫描速度均能大幅提高烧结件的抗拉强度,尤其对低树脂含量的覆膜砂强度提升幅度更为明显。另外,正交试验结果分析表明,工艺参数对激光烧结件抗拉强度的影响程度为:激光功率>扫描速度>铺粉层厚。在最佳工艺参数激光功率40w、扫描速度2000mm/s及铺粉层厚0.15mm的条件下,树脂含量2.5%的覆膜砂激光烧结件初坯强度达到了0.72MPa,比目前研究的覆膜砂的强度提高了120%,能满足激光烧结含精细结构砂型(芯)的强度要求。The coated sands（100/200 mesh） with different resin contents were designed and prepared for selective laser sintering.The forming processes of selective laser sintering were performed for investigating the effects of sintering parameters（spreading powder,laser power and scanning speed,etc） on the forming of coated sand.The results show that the tensile strength of the laser-sintered parts was obviously reduced with the increase of the layer thickness of spreading powder.The effective layer thickness of spreading powder of 100/200 mesh coated sand is 0.15mm^0.25mm.The tensile strength of sintered parts is substantially increased by increasing laser power or decreasing scanning speed,especially for low resin content.Moreover,the orthogonal experimental results show that the effect of process parameters on the tensile strength of laser-sintered parts are： laser power﹥scanning speed﹥layer thickness of spreading powder.The optimal process parameters is 40w laser power,2000mm/s scanning speed and 0.15mm layer thickness of spreading powder,the tensile strength of the laser-sintered original parts is 0.72MPa,increasing by 120% when compared with the present studies,which can satisfy the requirement for the fine structure of the laser sintering sand（core） strength.

关 键 词：选区激光烧结 覆膜砂 宝珠砂 力学性能 

分 类 号：TG242[金属学及工艺—铸造]