Si_3N_4陶瓷颗粒增强铝基复合材料压缩超塑性研究

Study on Compression Superplasticity of Aluminum Matrix Composite Reinforced with Si_3N_4 Ceramic Particles

采用热压法制备出了体积分数为20％的Si3N4陶瓷颗粒增强的2124铝基复合材料，对该材料的压缩超塑性进行了研究，确定了该复合材料压缩超塑成形工艺参数，并对其超塑性机理进行了初步研究。研究表明，该复合材料在一定的工艺条件下可实现压缩超塑性，其最佳超塑压缩温度为515℃，最佳初始应变速率范围为1．225×10^-4～1．225×10^-3／s，其超塑性压缩变形机制为适量的液相和动态再结晶共同调节的晶界滑动。

2124 A1 matrix composite reinforced by Si3N4 ceramic particles with 20% volume fraction was prepared by powder hot-press approach. The research of compression superplasticity on the composite was conducted. The superplastic forming parameters of the composite in compression state were elected. The superplastic mechanism of the composite was also preliminary studied. The results show that the composite can realize compression superplasticity under the certain process conditions, and the optimal superplastic deformation temperature is 515℃ and the optimal initial strain rate ranges from 1. 225×10^-4/s to 1. 225×10^-3/s, and the superplastic compressive deformation mechanism is that the grain-boundary sliding is regulated by both appropriate amount liquid phase and dynamic recrystallization.