旋压变形量对B4C增强铝基复合材料管微观组织及力学性能的影响

Influence of Spinning Deformation on Microstructures and Tensile Properties of B4C Particulate Reinforced Aluminium Matrix Composite Tube

采用等离子放电烧结+异步错距旋压方法制备了不同旋压变形量的B4C颗粒含量为10%(质量分数)的铝基复合材料管材,研究了变形量对复合材料管材微观组织和力学性能的影响。结果表明:随着旋压变形量的增加,B4C铝基复合材料管材内部B4C颗粒分布由类似网状结构变为均匀分布,B4C颗粒与基体铝合金之间界面形成了冶金结合;等离子放电烧结过程中的颗粒之间的'尖端放电'效应使得颗粒之间的界面处产生局部高温,促进了界面之间的结合,在界面处产生了AlB2和Al3BC金属间化合物;旋压变形量的增加,细化了铝合金的晶粒尺寸,减小了B4C的颗粒尺寸,但旋压过程中导致的大尺寸B4C颗粒的断裂弱化了细晶强化和颗粒强化对抗拉强度的作用。

The B4C particles reinforced aluminium matrix composite tube with different deformation was fabricated by spark plasma sintering(SPS)followed by asynchronous offset spinning.The effects of deformation on microstructure and mechanical properties of the composite tube were investigated.Results show that distribution of the B4C particles changes from net-like to relatively homogeneous in the aluminium matrix with the spun deformation increasing.Metallurgical bonding forms on the interface between B4C and aluminium;the local high temperature of the interface between particles caused by the top discharge between particles during SPS processing promotes the interface bonding.The interface mainly consists of AlB2 and Al3BC phase.With the deformation increasing,the aluminium grain and B4C particle are decreased in size.However,the large sized B4C particle fracture weakens the function of the fine-grain strengthening and particles strengthening for the tensile strength.