Patent ID: 7195681
Filing Date: 2007-03-27
Classification: C22C,C22F

Abstract:
1. A process for lowering the Martensitic Transformation Temperature(As) of shape memory alloy having a low martensitic transformation temperature, said alloy comprising Copper and Zinc in the range of 62–86% of Copper and 10–28% of Zinc along with 6% to 10% of Aluminum, by a re-betatising treatment of previously high temperature betatised material, said process comprising the following steps of: (i) selecting an alloy composition comprising Copper and Zinc in the range of 62–86% of Copper and 10–28% of Zinc along with 6% of Aluminum; (ii) melting the alloy composition in an induction furnace operating in air under charcoal cover followed by casting into desired shapes to form a shaped material; (iii) homogenizing the shaped material at 800° C. for a period of about two hours followed by cooling; (iv) surface machining the shaped material for removing oxide scale formation; (v) re-heating the shaped material at about 575° C. for about three minutes (vi) quenching said shaped material with cold water for obtaining a fully martensitic structure; (vii) recording the temperature and structure of the material.