| Fe-Mn-Si shape memory alloy has a one-way shape memory effect, mainly used in the constraint restored occasions, thread locking is one of the applications. So far, the studies of Fe-Mn-Si shape memory alloy threaded connection locking have focused on the locknut, and based on the recovery of Fe-Mn-Si shape memory alloy constraints locking bolt has not yet published in the paper. Proceed form the bolt locking mechanism, the process developed in Fe-Mn-Si shape memory alloy locking indicators and re-use properties of the bolts tight solid locking performance to make a comprehensive evaluation.The study showed that the threaded surface of the bolt connection produce the axial restoring force and radial restoring force after the process of pre-deformation treatment of Fe-Mn-Si shape memory alloy locking bolt, the two parts of restoring force can be transformed into frictional torque to prevent relative rotation between the screw pairs, and then play a locking. Combined with the process of Fe-Mn-Si shape memory alloy locking bolts and connection process, and by means of elastic mechanics, mechanical engineering and theoretical knowledge of its preload generated by self-locking friction torque T1, axial restoring force generated by the self-locking self-locking friction torque T2 as well as radial restoring force generated by the friction torque T3 were characterized.Through the connection in Fe-Mn-Si shape memory alloy locking bolts locking torque test analysis shows that, as the recovery temperature is gradually increased in the same pre-deformation, the anti-loosing friction torque, axial friction torque and radial friction torque increase, the axial friction torque T2 and radial friction torque T3 contribution to the anti-loosing friction torque gradually increases. For different pre-deformation of the new bolts, the same recovery temperature, with a gradual increase of the pre-deformation, anti-loosing friction torque, axial friction torque and radial friction torque increases in both the axial friction torque T2 and radial friction torque T3 contribution to the anti-loosing friction torque gradually increases. When the recovery temperature is 500℃the anti-loosing friction torque increased by 255.35% than ordinary(0.8 T1),which is nearly three ordinary bolts times. The Fe-Mn-Si shape memory alloy locking bolts repeat performance test results show that control the recovery temperature, either to ensure the bolt locking performance and can improve the performance of the performance of the repeated use of the bolts.In Fe-Mn-Si shape memory alloy locking bolts to connect the dynamic locking performance tests available, the role of the lateral load (vibration, shock and load), Fe-Mn-Si shape memory alloy bolt locking life is much higher than ordinary bolts. For example, in the vibration frequency is 12.5Hz, the conditions of lateral loading force of 15N, the vibration time is five times that of ordinary bolts. |
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