Gold/palladium alloys are used mainly in jewellery. Commonly known as white gold, they often substitute platinum. Although gold/nikel alloys are also referred to as white gold, palladium white gold is softer and more ductile compared to nickel white gold. When added to gold, palladium makes the metal stronger and harder, as well as increasing its melting point and elastic modulus. These alloys are called white gold as they transform the characteristic yellow of gold to white.
Palladium is also more expensive and harder to process than nikel, making the cost of palladium white gold higher.
In the mid-1980´s the first generation of long-life spark plugs with corrosion resistant platinum or gold/palladium electrodes were put on the market. In recent years it seems that platinum, and more recently, iridium electrodes are proving to be more popular with manufacturers and consumers, although plugs containing gold-palladium electrodes can still be sourced.
Other applications for gold/palladium alloys include aerospace, electronics, chemical processing, geochemistry, glass manufacturing, hydrogen separation, implantable medical devices, thermocouple sheaths, and musical wind instruments to name a few.