【摘要】 为了提高冷源的利用效率并合理设计低温粉碎工艺,需要深入了解橡胶材料的低温力学性能,对橡胶试样开展常温和低温下的拉伸实验。常温下,橡胶的黏弹性作用显著,达到破裂的形变量大且拉伸时间较长,拉伸应力伴随着持续性波动,塑性形变较大并消耗能量。液氮温度下橡胶表现出明显的脆性并发生自发的破裂。采用升华温度为195 K的干冰冷却橡胶样品,橡胶的黏弹性被抑制,应力波动现象也随之消失,拉伸应变减小但应力增大,低温下拉伸断裂的耗功远小于常温拉伸,体现了低温粉碎的优势。更多还原

【Abstract】 To improve the efficiency of cold source and the design of cryogenic grinding process,it is necessary to fully understand the cryogenic mechanical properties of rubber materials. Tensile experiments of rubber samples were carried out at room temperature and cryogenic temperature,respectively. At room temperature,the rubber showed noticeable viscoelastic characteristics with large deformation and long stretching time. The stress fluctuated continuously. The plastic deformation was large,which aggravated energy consumption. At liquid nitrogen temperature,the rubber was brittle with spontaneous rupture. When the rubber samples were cooled with dry ice at a sublimation temperature of 195 K,the viscoelasticity of the rubber was diminished,and the stress didn’t fluctuate. The tensile strain decreased but the stress increased. The fracture at cryogenic temperature consumed less energy compared with that at room temperature.更多还原