老化（aging / ageing）
材料性能在零外部应力和恒定温度条件下随时间发生的自发变化。
Aging (ageing)
The spontaneous change of a material property with time, under zero external stress and constant temperature.
材料性能在零外部应力和恒定温度条件下随时间发生的自发变化。
The spontaneous change of a material property with time, under zero external stress and constant temperature.