离心反应熔铸TiB2基/42CrMo合金钢梯度复合陶瓷材料层间缺陷研究  

Interlaminated Defect Research of TiB base Ceramic/42CrMo Alloy Steel Gradient Composite Prepared by Centrifugal Reactive Casting Processing

作　　者：李维锴 韩保红 赵忠民 LI Weikai;HAN Baohong;ZHAO Zhongmin(Shijiazhuang School,Army Engineering University,Shijiazhuang 050003,China)

机构地区：[1]陆军工程大学石家庄校区,河北石家庄050003

出　　处：《热加工工艺》2020年第24期75-79,共5页Hot Working Technology

基　　金：国家自然科学基金资助项目(51072229);武器装备预研基金项目(9140A12040213JB34001)。

摘　　要：在(Ti+B4C)燃烧体系中引入Ni添加剂,采用超重力场自蔓延离心反应熔铸技术制备出TiB2基/42CrMo合金钢梯度复合材料。观察材料中存在的裂纹和孔洞两种微观层间缺陷并探讨其形成机理。结果表明,在凝固过程中,液态陶瓷遵循表面自下而上与底部自上而下的双向凝固顺序,使得在其心部偏下位置形成金属液膜,液膜受力断裂即产生热裂纹。为消除热裂倾向,可减少金属添加剂的含量、加快凝固速率。由于受强风激冷作用,陶瓷表面率先形成凝固壳层;后续凝固过程中,陶瓷液相无法得到补充,以致在陶瓷内部形成缩松、缩孔。通过改善压坯质量、改变物料成分、改善保温环境都可以有效减少材料内部孔洞。The Ni additive was intro duced into(Ti+B4C) combustion system, the TiB2 base/42CrMo alloy steel gradient composite was prepared by supergravity field self-propagating centrifugal reaction melting casting. The microlaminar defects of cracks and voids were observed and the formation mechanism was discussed. The results show that, in the process of solidification, the liquid ceramics follow the bidirectional solidification sequence of bottom-up for bottom part and top-down,which results in the formation of liquid metal film near the bottom of the liquid ceramic, and the cracking under the force of the liquid film leads to the hot crack. In order to eliminate hot cracking tendency, the content of metal additive can be reduced and solidification rate can be accelerated. Due to the strong wind and cold action, the solidified shell is formed on the ceramic surface. In the subsequent solidification process, the liquid phase of the ceramics cannot be replenished, resulting in the formation of shrinkage and porosity in the ceramics. By improving the quality of embossed embryo, changing the composition of materials and improving the thermal insulation environment, the internal pores of the materials can be effectively reduced.

关 键 词：离心反应熔铸 陶瓷/金属连续梯度复合材料 热裂纹 孔洞 

分 类 号：TB333.13[一般工业技术—材料科学与工程] TG249.4[金属学及工艺—铸造]