真空浸渗水玻璃对选择性激光烧结覆膜砂强度的影响  

Effect of Vacuum Impregnation of Sodium Silicate on Strength of Selected Laser Sintering Resin Coated Sand

作　　者：王祥宇 薛铠华 姚山 张雪[1] WANG Xiang-yu;XUE Kai-hua;YAO Shan;ZHANG Xue(School of Materials Science and Engineering, Dalian University of Technology, Dalian 116085, Liaoning, China)

机构地区：[1]大连理工大学材料科学与工程学院,辽宁大连116085

出　　处：《铸造》2018年第7期569-574,共6页Foundry

摘　　要：采用真空浸渗工艺,对已固化覆膜砂型浸渗不同浓度的水玻璃/二氧化硅混合液,测试了混合液浓度对覆膜砂型的常温抗拉强度和高温残留强度的影响,利用高倍率影像测量仪观察并比较了不同浓度的混合液在覆膜砂型中的形貌分布变化。研究结果表明,真空浸渗工艺能使水玻璃/二氧化硅混合液完全渗透进砂型内部,混合液硬化后,试样的常温抗拉强度最高达到8.38 MPa,强度增加超过5 MPa;在1 000℃高温,加热5 min的条件下,含有水玻璃的试样仍有较高的强度,试样表面完整,没有任何砂粒脱落,同时保持一定的溃散性。Vacuum infiltration process was used to infiltrate different concentrations of sodium silicate binders on the coated sands. The influence of sodium silicate concentration on the normal temperature tensile strength and high temperature residual strength of the coated sands was tested, and the high magnification image measuring instrument was used. The changes of morphology distribution of different concentrations of sodium silicate in the coated sand mold were observed and compared. The results show that the vacuum infiltration process can make the high viscosity sodium silicate completely penetrate into the sand mold. After the sodium silicate is hardened, the tensile strength of the sample at the normal temperature reaches 8.38 MPa and the strength increases more than 5 MPa. Holding at 1 000℃ for 5 min, the sample containing sodium silicate still has high strength, the surface of the sample is intact, no sand grains shed, and the sample maintains certain collapsibility.

关 键 词：真空浸渗 覆膜砂 水玻璃/二氧化硅 高温性能 

分 类 号：TG221[金属学及工艺—铸造]