Spangold

The topic of this article may not meet Wikipedia's general notability guideline. Please help to demonstrate the notability of the topic by citing reliable secondary sources that are independent of the topic and provide significant coverage of it beyond a mere trivial mention. If notability cannot be shown, the article is likely to be merged, redirected, or deleted. Find sources: "Spangold" – news · newspapers · books · scholar · JSTOR (May 2021) (Learn how and when to remove this message)

Spangold is a family of shape memory-effect alloys (SME) of gold, copper, and aluminum in either 18K or 23K. The name of the family is a play on the word "spangled".^[1]

Spangold is a beta-phase alloy with a nominal stoichiometry of Au₇Cu₅Al₄ and a nominal composition by mass of 76% gold, 18% copper, and 6% aluminum. The texture is caused by the induction of a martensitic-type phase transformation on a polished surface.^[2][3]

Spangold undergoes a martensitic-type phase transformation when properly treated.^{[citation needed]} This phase transformation is induced on a polished surface of the alloy.^{[citation needed]} Martensitic transformations are a common feature in shape memory alloys, and they involve a reversible change in crystal structure that allows the material to recover its original shape when subjected to specific temperature changes.^{[citation needed]}