Cf/Mg复合材料热膨胀系数及其计算

Coefficient of Thermal Expansion and Compute of Carbon Fibre Reinforced Magnesium Composites

摘要:

利用热膨胀仪测定压力浸渗法制备的单向碳纤维增强镁复合材料在20~300 ℃区间的平均热膨胀系数，讨论热处理工艺、碳纤维弹性模量、基体合金种类等因素对连续纤维增强镁基复合材料热膨胀系数的影响。结果表明，可以通过退火处理降低复合材料的热膨胀系数。同时，选择高模量石墨纤维或选择低屈服强度基体合金都可以获得低热膨胀系数的复合材料。对计算复合材料横向热膨胀系数的理论公式进行改进，与实验测试值比较，理论计算值更加接近实际测试值。提出计算层合板结构复合材料二维平面内热膨胀系数的模型，计算出不同铺层方式下层合板复合材料的

Abstract:

60vol %Carbon fiber reinforced magnesium matrix composites were fabricated by pressure infiltration method. The coefficient of thermal expansion measurement of carbon fiber reinforced magnesium matrix composites were carried out on a dilatometer 402C at the temperature ranged at 20~300 ℃. The relations among α and heat treatment condition, elastic modulus of the fibers and yield strength of matrix alloys were investigated. Results showed that α of the composites decreased with increasing of elastic modulus of fibers and reducing of yield strength for matrix alloys. Moreover, the α of composites decreased after annealing treatment. In this paper, the estimate formula of the α in transverse direction of composites is presented, and this calculation method should minimize the error between the calculation value and the true value. The model for laminate structure composite α in 2D planar is suggested, and the α of [0/±15/±30/±45/±60/±75/±90]S laminates are isotropy.