Nickel alloys are nickel-based alloys (mixtures of nickel with other metals such as iron, copper, lead, etc.) which generally offer exceptional resistance to corrosion and high temperatures. These alloys are intended to improve certain specific properties of nickel that are of most interest, depending on the intended use. These alloys have various properties, such as heat resistance, electrical resistance, toughness, low and high temperature resistance, corrosion resistance, electronic and magnetic properties. A low level of impurities is sought in order to minimise sensitivity to hot cracking and micro-cracking. Their field of use is mainly in the chemical, petrochemical, nuclear, naval, marine and aerospace industries. Nickel alloys have therefore become indispensable for the production of industrial components subjected to very demanding behaviour.