基于温度场模拟的铸件表面硼化物梯度耐磨材料成形机制

Process mechanism of wear-resisting gradient borides material on cast surface by FEM analysis of temperature field

利用ANSYS10.0,对铸件表面硼化物梯度耐磨材料成形过程中温度场进行了模拟验证,对梯度耐磨材料不同部位的成形机制进行了分析研究,结果表明,模拟结果与试验结果较为吻合,合金粉块不同部位温度变化将影响复合材料的质量,内层及中间层温度高,高温持续时间长,熔合质量好,而对于最外层,温度较低(<1000℃),高温持续时间短,尖角处温降快,导致这些部位复合材料熔合质量较差、缺陷较多。进一步研究表明,砂型材料的导热率及合金粉块内低熔点的熔合剂过多均会影响复合材料的质量。

The temperature during the fabrication of wear-resisting functional gradient borides material （FGM） on cast surface was simulated and verified by using ANSYS10.0 program. The simulation results agreed very well with the experimental ones. The process mechanism of wear-resisting FGM at different positions was investigated. The results indicate that the temperature variation at different positions of the gradient alloying powders block will affect the quality of FGM. The temperature of inner and medium layer of block is higher and the duration continues longer, which leads the FGM more strongly. However, because of the temperature quick-drop in the alloy powders block on corners, lower amount in outer layer, many defects and poor quality will proceed. Further results indicate that the thermal conductivity of sand mold and the high fraction of binder alloying for the low melt point in the block will affect the quality of FGM.