基于纳米压入技术的老化橡胶表面力学行为

Surface Mechanical Behaviors of Aging Rubber by Nanoindentation Technology

为了研究不同老化时间和温度对橡胶表面力学性能的影响,通过纳米压痕仪测量了老化前后以及不同老化时间和温度下橡胶的弹性模量、硬度、储能模量、损失模量和损耗因子。研究结果表明,老化时间和温度是影响橡胶表面纳米力学性能的2个关键因素,且相比于老化时间,老化温度对橡胶力学性能的影响更为显著;在90℃和105℃老化温度下,橡胶的弹性模量、硬度、损耗因子等力学性能受老化时间的影响较小;在120℃以上,随着老化时间的延长,橡胶的硬度、弹性模量逐渐增大,蠕变性能与黏性逐渐减弱;在135℃时,其力学性能呈现先快后慢的变化模式,老化3d之后,其硬度与弹性模量开始迅速增大,后期变化速率逐渐减小。在工程上,对于长期服役于较高温度下的密封件来说须严格控制其服役温度,以达到防止密封件老化、提高密封寿命的目的。

In order to study the influence of different aging time and temperature on the mechanical properties of rubber surface,the elastic modulus,hardness,storage modulus,loss modulus and loss factor of rubber at different aging time and temperature were measured by nano-indenter.Results show that the aging time and temperature are two key factors that affect the nanomechanical properties of rubber surface.Compared with the aging time,the aging temperature has a more significant impact on the mechanical properties of rubber.The elastic modulus,hardness,loss factor and other mechanical properties of rubber are less affected by aging time at 90℃and 105℃of aging temperature.Above 120℃,the hardness and elastic modulus of rubber gradually increase and the creep performance and viscosity gradually decrease as the aging time increases.The growth rate of the mechanical properties of rubber changes from low to first fast and then slows at 135℃.After 3 dof aging,the hardness and elastic modulus of rubber begin to increase rapidly and then the rate of change gradually decreases.For the seals used for a long time at higher temperature in engineering,the service temperature must be strictly controlled to prevent them from aging and improve their seal life.