深冷处理时间对3D-C_f/Al复合材料残余应力与力学性能的影响  

Effect of cryogenic treatment time on residual stress and mechanical properties of 3D-C_f/Al composites

作　　者：姜小坤 余欢 徐志锋 刘剑 蔡长春 JIANG Xiao-kun;YU Huan;XU Zhi-feng;LIU Jian;CAI Chang-chun(National Defense Key Discipline Laboratory of Light Alloy Processing Science and Technology,Nanchang Hangkong University,Nanchang 330063,China)

机构地区：[1]南昌航空大学轻合金加工科学与技术国防重点学科实验室

出　　处：《材料热处理学报》2018年第10期1-7,共7页Transactions of Materials and Heat Treatment

基　　金：国家自然科学基金资助项目(51365043)

摘　　要：采用真空气压浸渗法制备了三维五向编织M40碳纤维增强铝基复合材料（3D-C_f/Al）,其增强体体积分数为51%,随后对3D-C_f/Al复合材料进行了液氮-196℃的深冷处理,探讨了深冷处理时间对3D-C_f/Al复合材料性能的影响以及作用机制。结果表明：深冷处理对3D-C_f/Al复合材料的力学性能和残余应力有显著的影响。随着深冷处理时间的延长,其拉伸强度呈逐步上升的趋势。经深冷处理36 h,拉伸强度达到最高620.09 MPa,相比铸态486.02 MPa提高了27.59%,其弹性模量高达173.81 GPa,相比铸态144.43 GPa提高了20.3%;深冷处理后,复合材料基体残余热应力明显降低,且随着深冷处理时间的延长,复合材料的残余应力状态发生了改变,基体由受拉伸应力转变为受压缩应力。深冷处理过程中因体积收缩效应导致的孔隙闭合及深冷处理使复合材料的残余应力降低是复合材料力学性能得以提高的原因。A three-dimensional, five-direction braided M40 carbon fiber reinforced aluminum matrix composites（3 D-C_f/Al）were prepared by vacuum pressure infiltration, and the volume fraction of the reinforcements was 51%. The 3 D-C_f/Al composites were cryogenic treatment with liquid nitrogen at-196 ℃, and the influence of cryogenic treatment time on mechanical properties of the 3 D-C_f/Al composites and its mechanism were discussed. The results indicate that cryogenic treatment has a significant effect on the mechanical properties and residual stress of the 3 D-C_f/Al composites. With the increasing of cryogenic treatment time, the tensile strength of the 3 D-C_f/Al composites increases gradually. After cryogenic treatment for 36 h, the tensile strength reaches the maximum of 620.09 MPa with an increase of 27.59% compared with the as-cast 486.02 MPa, and its elastic modulus is up to 173.81 GPa and 20.3% higher than that of as cast 144.43 GPa. After cryogenic treatment, the residual thermal stress of the matrix of the composites decreases obviously, and with the increasing of cryogenic treatment time, the residual stress state of the composites changes from tensile stress to compressive stress. The pore closure caused by volume shrinkage and the reduction of residual stress during cryogenic treatment should be responsible for the improvement of the mechanical properties of the composites.

关 键 词：3D-C_f/Al复合材料 深冷处理 残余应力 力学性能 真空气压浸渗 

分 类 号：TB333[一般工业技术—材料科学与工程]