We offer a line of APT, chromium carbide and tungsten carbide powders to combat high- and low-temperature wear on your most critical components.
Using the most advanced oxide powder fabrication techniques, we manufacture a wide range of aluminum-, chromium-, yttrium- and zirconium-oxide based ceramic powders that are critical for resisting heat and wear.
Our MCrAIY powders are composed of cobalt or nickel (or both) alloyed with aluminum, chromium or yttrium to create the foundation for gas turbine hot section thermal spray coatings.
We offer a wide range of aluminum-, cobalt-, copper-, iron-, molybdenum- and nickel-based alloy powders to meet even your most demanding application requirements.
What is Thermal Spray powder?
Thermal spray powder essentially refers to the powder material that will be melted in-flight and then deposited on a prepared substrate to form a protective coating. Powders for thermal spray are produced in multiple ways:
- Atomization: During this process, molten metal is sprayed to form tiny droplets. These droplets rapidly solidify to make a powder. Metal powders produced this way include iron-, nickel-, titanium-, cobalt-based alloys, stainless steel, copper, brass, bronze, aluminum, tin, and zinc.
- Chemical: Chemical treatments usually involve the processes of dissolving oxides, precipitation from solutions and heat-treating (calcining). Oxide reduced powders tend to have a spongy state due to the pores in each particle. Precipitation produced powders provide a narrow particle size and high purity. Thermal decomposition is often used to process carbonyls, which once fully processed tend to have a high percentage of purity. Overall, this method of metal powder production produces powders that are very pure.
- Solid state reduction: During this process, selected ore is crushed, mixed with a reducing species like carbon, and passed through a furnace which results in a cake of sponge metal being formed. The sponge metal is then crushed, separated and sieved to produce powder. This is a tried but true process for metal powder production, however it can take up to 3 days in a furnace to reduce the ore. In addition, the purity of the ore that is put into this process is the purity of the resultant product.
- Spray-drying: Fine raw materials are prepared in a liquid-based (either water or solvent) slurry and sprayed into tiny droplets either via high velocity gas or rotating wheels. The droplets liquid is evaporated via hot air or other process gas and the agglomerates are collected. These agglomerates are then fired in a variety of atmospheres depending on the material composition. This process produces semi-dense, spherical, free-flowing powders. It can be used for oxides, carbides, and metallic materials.
Examples of common metal powders used include zinc, tin, nickel, iron, granular copper and aluminum powder. However, since not all thermal spray processes involve metal powder, there are also plastics, ceramics and alloys and composites available to be thermal sprayed on a surface.
Praxair Surface Technologies offers a complete line of powders for thermal spray applications as well as additive manufacturing. Other offerings include thermal spray systems, powder feeders, acoustical enclosures and more that will help you reach your goals. Learn more about our equipment solutions here.