The copper-nickel-titanium sputtering targets are made by the controlled alloying of copper, nickel, and titanium. The alloy results in a material with good electrical conductivity, good corrosion resistance, and increased mechanical strength. Because of these properties, the targets are used in a broad range of industries, including optics, where thin film coatings are required, electronics, where conductive layers are needed, decorative applications, where a finish is provided, and in mechanical where durable and wear-resistant coatings are needed.
Process Steps of Preparing Copper-Nickel-Titanium Alloy Target
Preparation of Input Materials: Use copper and nickel in plate form and titanium in sponge form, having purities of over 99.9%. Afterwards, take the materials and weigh them according to the alloy desired composition, which can be (Cu: 50-70%, Ni: 20-30%, Ti: 10-20%, for example, Cu-30Ni-5Ti wt%).
Vacuum Melting Process: Input the starting materials of copper, nickel and titanium into the crucible in the ratios outlined above. To achieve better results, place nickel and titanium (which have a higher melting point) below and place copper on the top so that there can be even melting. Afterwards, you have to evacuate the furnace to achieve a vacuum of 10^-3 to 10^-4 Pa, and then refill with high-purity argon to achieve a protective atmosphere. Finally, the temperature is increased to the range of 1600-1800°C. Since this is above the melting point of titanium (1668°C), all of the metals will be completely molten. Stirring is carried out via electromagnetic or mechanical means to homogenise the melt. The temperature is held for 10–20 minutes to reduce segregation. Finally, the molten metal is poured into a preheated graphite or copper mould and allowed to cool, forming a solid alloy ingot.
Homogeneous treatment: The alloy ingot is placed into a box-type resistance furnace and held at 800-950℃ (which is below the solidus temperature of the alloy) for 2-4 hours of furnace cooling.
Hot working: It processes involve heating the homogenised alloy ingot to a temperature ranging from 700 to 900 degrees Celsius. At that temperature, the alloy goes through a unidirectional forging machine or a rolling mill to be plastically deformed into a target billet.
Annealing treatment: It processes of the billet involve equilibrating the temperature to 600 to 750 degrees Celsius for 1-2 hours, after which the billet can be air- or furnace cooled.
Machining: The target billet goes through processes like leading, turning, and surface grinding to get the target dimensions and surface finish.
Uses of Copper-nickel-titanium alloy target
Electronics: Used as a barrier layer in thin films for semiconductors and displays.
Optical coatings: used for an aspect of the production of highly reflective mirrors and filters.
Abrasion-resistant coatings: used on the surfaces of tools and moulds to provide a hard protective coating.
Decorative coatings: used to enhance mobile phone casings, jewellery and other decorative items with a hard protective coating.
Aerospace: Used to provide functional coatings that are resistant to high oxidation and high temperatures.
