Thermal spray hard surfacing is a process that uses flames to spray metal powders onto a workpiece, strengthening its surface. It improves wear, corrosion, heat, and oxidation resistance, while also fixing dimensional defects. It is widely used and cost-effective.
Thermal spray technology began in 1910 with Dr. M V Schoop's use of an oxygen-acetylene flame spray gun for metal spraying. Over time, spraying materials have advanced from metal wires to metal powders, including atomized pre-alloyed powders and coated composite powders, which are now widely used and successful.
Thermal spray powders, including self-fusing alloys, self-bonding alloys, corrosion-resistant and oxidation-resistant alloys, ceramics, metal ceramics, and composite powders, require consideration of particle size, shape, flowability, and composition. The deposition efficiency of the powder during thermal spraying should typically range from 80% to 95%.
Self-fluxing alloy powder forms a pore-free dense layer on workpiece surfaces when melted in normal atmospheric conditions. These alloys contain boron and silicon fluxes that prevent oxidation and form an anti-oxidation borosilicate "glass." The resulting coating has high hardness, wear resistance, and abrasion resistance, making it ideal for workpieces requiring wear and corrosion resistance.
These oxidation-resistant alloy powders are known for their excellent resistance to oxidation and corrosion, making them ideal for applications in high-temperature environments. They can be used to protect surfaces from oxidation or to repair damaged surfaces. These powders are also cost-effective compared to other alloy powders.
The development of spraying equipment has led to the creation of composite powders, a versatile thermal spray material with various applications. These powders consist of different materials combined, forming multiphase particles. They can be categorized into coating type and non-coating type based on their structure. The composition and distribution of components within the particles are generally uniform.
Coating-type composite powders can be classified into five types based on their composition, performance, and applications:
- The first type is self-bonding, which uses metal cores with nickel or cobalt coatings. It is used to manufacture self-bonding alloy powders.
- The second type is wear-resistant, with cores made of WC, TiC, BN, Cr3C2, SiC, TiN, diamond, etc., and metal coatings. It can be used to produce processing tools or wear-resistant coatings.
- The third type is sealable, with cores made of easily worn and relatively soft powders, and metal coatings. It is used to manufacture wear-resistant coatings or components for lubrication and sealing purposes.
- The fourth type is corrosion-resistant with titanium, zirconium, chromium, chromium oxide cores, nickel, cobalt, copper, silver, and gold coatings. It is used for corrosion-resistant surface coatings.
- The last type is heat-insulating and heat-resistant with zirconia, alumina, and titanium oxide cores coated with metal as a binder. This improves resistance to heat, wear, and erosion and is widely used in aerospace engines and spacecraft.
Thermal spray metal spherical powder material has broad application prospects. With the continuous progress of technology and the emergence of new materials, thermal spray technology will be increasingly valued in the future.
Heeger Materials is a reputable supplier offering Thermal Spraying Powder products at competitive prices, which are widely used in research and science fields. If you're interested, feel free to contact us at [email protected] for a quote, and we guarantee a response within 24 hours.