【摘要】 在Gleeble-1500D 热模拟实验机上对30ZrCp/W 复合材料进行高温压缩实验,变形温度和应变速率分别为800℃~1 200℃和10-3 s-1~1 s-1,研究其高温压缩变形的流变应力行为。研究表明:随变形温度升高,复合材料的流变应力下降,在10-3 s-1 和1 200℃下,抗压强度为948.7 MPa。在800℃下发生伪塑性变形,未达到预设变形量,真应力-真应变曲线上表现出的塑性为伪塑性,其是由微裂纹的萌生-钝化引起的。随变形温度升高,复合材料发生动态回复再结晶。随应变速率升高,真应力-真应变曲线形状从“锯齿”型向“平滑”型转变。复合材料对应变速率不敏感,随应变速率升高,复合材料的流变应力略有升高。在800℃和1 s-1 下,复合材料的抗压强度为1 176.9 MPa。用Arrhenius 方程描述复合材料在1 000℃~1 200℃的热变形行为,变形激活能为811.4 kJ/mol。更多还原

【Abstract】 High temperature compressive experiments of 30ZrCP/W composite at 10-3s-1~1s-1 and 800℃~1 200℃ were performed on Gleeble-1500D thermal simulation device. The flow stress behavior of the composite was studied. The experimental results indicate that the flow stress of the composite decreases with the increasing of deformation temperature, and the compressive strength is 948.7 MPa at 1 200℃ and 10-3 s-1. At 800℃, the plastic deformation of the composite does not accomplish the pre-set strain, and the plastic character in true stress-true strain curves is pseudo-plasticity, which is caused by the behavior of microcracks initiating-passivating. Dynamic recovery and recrystallization of the composite generate with the increasing of deformation temperature. The shapes of true stress-true strain curves transform from serration to smoothing with the increasing of strain rate. The composite has lower sensitivity to strain rate, and the flow stress of the composite increases with the increasing of strain rate, though the increment is little. The compressive strength is 1 176.9 MPa at 800℃ and 1s-1. The deformation activation energy of the composite is 811.4 kJ/mol at 1 000℃~1 200℃ from Arrhenius equation.更多还原