【摘要】 目的解决铝基复合材料异形件形状特征复杂,对良好的抗拉和抗剪切等使用性能有较高要求,制备难度较大等问题。方法提出了"铺层-缠绕-缝合"碳纤维异形件预制体制备方法,设计了直接式缝合、插销式缝合、整体式缝合3种成形方案,通过理论计算分析不同方案预制体的力学性能;在此基础上,采用液固高压成形Cf/Al复合材料异形件,并通过断口形貌、微观组织以及致密度的分析,解释了其力学性能提升的原因。结果根据较佳的预制体成形方法,成功制备了预制体和复合材料异形件;异形件内部未发现气孔、微裂纹等缺陷,Cf/Al复合材料拉伸强度达278MPa,较基体提高了114%。结论整体缝合法为较佳的预制体成形方案,可使构件具有较高的连接强度和定位精度;复合材料内部浸渗良好,致密度达98.59%,故该复合材料的力学性能较铝合金基体提升较多。更多还原

【Abstract】 The paper aims to solve the complicated shape characteristics, the high application requirements on tensile and shear resistance and the preparation difficulty of the special-shaped aluminum matrix composite. The "laying-winding-stitching" process for preparing carbon fiber preforms of special-shaped parts was proposed. Three forming schemes including direct stitching, bolt stitching and integral stitching were designed. Tensile properties of the preform for different schemes were analyzed by theoretical calculation. On this basis, the special-shaped C_f/Al composite parts were fabricated by liquid-solid high pressure technique. Through the analysis of tensile fracture, microstructure and density, the reason for the improvement of mechanical properties was explained. Preforms and special-shaped composite parts were prepared successfully through the superior preform forming method. The special-shaped parts had no defects such as microcracks and porosities. The tensile strength of the composite was 278 MPa, which was 114% higher than that of the matrix. The integral stitching is the optimal method, which makes the perform component have high connection strength and positioning accuracy. The composite is well impregnated inside, and its relative density is up to 98.59%. Therefore, the mechanical properties of the composite can be improved more than that of the aluminum alloy matrix.更多还原