A method of pipe joining using shape memory alloys

Abstract

An alternative method of pipe joining using shape memory alloys is proposed in this study to remove the difficulty caused by errors of pipe size. The conventional method is composed of deformation of shape memory alloys (SMAs) coupling below M-s, installation of the deformed coupling pipes to be joined and heating above A(f). The deformed coupling should be inserted over the pipes to be joined as tightly as possible to secure the highest joining force. However, diameters of pipes to be joined are different from pipe to pipe and moreover, the size of deformed couplings is scattering, therefore it is difficult to get the tightness. In this study, the problem is settled by deforming SMA coupling and pipes to be joined simultaneously with the coupling inserted in the pipes. By doing so, the tightness is always maintained. The new method makes it possible to apply alloys with a poor shape memory effect to pipe couplings. Some another expected advantages will be discussed. (c) 2006 Elsevier B.V. All rights reserved.