短切硅酸铝纤维增强硅溶胶型壳的抗弯强度及高温自重变形

发布时间：2018-10-17 15:22

【摘要】：为了提高熔模铸造硅溶胶型壳的性能,向涂料中添加硅酸铝纤维制备纤维增强熔模铸造型壳试样。对不同纤维加入量条件下所获得的纤维增强型壳试样的常温及焙烧后抗弯强度、高温自重变形量的变化规律进行研究,并利用SEM观察型壳试样断口形貌。结果表明:随硅酸铝纤维加入量从0.2%~1.0%(质量分数,下同)变化,其常温抗弯强度显著增大,高温自重变形量减小;纤维加入量为1.0%时,试样的常温抗弯强度较未增强的试样提高了47%,而高温自重变形减少约50%。采用0.2%~1.0%的硅酸铝纤维增强后,复合型壳焙烧后强度至少提高39%。断口SEM形貌观察分析结果表明,纤维增强硅溶胶型壳试样受力破坏失效主要由于硅溶胶凝胶膜的断裂、硅酸铝纤维拔出、断裂及脱粘等综合作用所致。
[Abstract]:In order to improve the properties of silica sol mold shell in investment casting, fiber reinforced investment casting mold shell samples were prepared by adding aluminum silicate fiber to coating. The changes of bending strength and weight deformation at room temperature and calcination of fiber reinforced shell samples obtained under different fiber content were studied. The fracture morphology of shell specimens was observed by SEM. The results show that the flexural strength at room temperature increases significantly and the deformation of weight at high temperature decreases with the addition of aluminum silicate fiber from 0.2% to 1.0% (mass fraction), and when the fiber content is 1.0%, The flexural strength of the specimen at room temperature is increased by 47% than that of the specimen without reinforcement, while the deformation of dead weight at high temperature is reduced by about 50%. The strength of the composite shell was increased by at least 39% after calcination with 0.2% aluminum silicate fiber and 1.0% aluminum silicate fiber. The results of SEM observation and analysis show that the failure of fiber reinforced silica sol shell specimens is mainly caused by the fracture of silica sol gel film, the pull-out, fracture and debonding of aluminum silicate fiber.
【作者单位】：内蒙古工业大学材料科学与工程学院;
【基金】：春晖计划资助项目(Z2011-062)
【分类号】：TG249.5;TG22

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