热循环对铜基记忆合金管接件性能的影响

The Effect of Thermal Cycling on Cu—Based SMA Coupler Performances

通过实验研究了热循环对铜基记忆合金管接件性能的影响,研究并将管接件和管接组件(管接件与钢管的装配件)进行冷热循环实验,观察在不同扩孔变形度和过盈量下记忆性能和联接性能的变化规律.

The effects of thermal cycling between the parent and martensite phases temperature range on Cu-Based SMA coupler performances have been studied. The experimental results show that the recovery ratio of cold-expanded cou- pler is reduced quickly and get a stable value gradually during thermal,cycl- ing.And the recovery ratio reduces more quickly in the coupler of larger cold-expanded ratio,the recovery ratio is larger.A pair of steel tubes is installed lightly in coupler at martensite state,the coupler holds strongly steel tubes and has better gas tightness while the martensite is reversed into parent phase.As the interference between the SMA Coupler and steel tubes at parent phase temperature range is larger,the microcracksincold-expanding are expanded as well as other microcracks are created during thermal cycling os that the holding force and gas tightness reduce severely.Inversely as the interference is smaller,the holding force doesnlt reduce obviously and the gastightness is smaller we must choose advisable intereference so as to assemble the coupler and tubes to keep larger holding force and gastightness in parent phase temperature range long.