Special powder for high-speed laser cladding

Laser cladding powder is a special material used in laser cladding technology, with specific compositions and properties. The following is a detailed introduction to laser cladding powder:

I. Classification by composition

1. Self-fluxing alloy powder

   • Nickel-based self-fluxing alloy powder: Based on nickel as the matrix, containing alloying elements such as boron and silicon. For example, Ni60 alloy powder has good heat resistance, corrosion resistance, and wear resistance. It has a relatively low melting point and good self-fluxing property, and can form a uniform and dense cladding layer during the laser cladding process. It is commonly used in the preparation of wear-resistant and corrosion-resistant coatings for mechanical parts, such as the repair and strengthening of components like shafts and gears.

   • Cobalt-based self-fluxing alloy powder: With cobalt as the main component, while adding elements such as chromium, tungsten, and molybdenum. Co - Cr - W alloy powder has high red hardness, thermal stability, and wear resistance, and can still maintain good performance in high - temperature environments. It is suitable for the cladding of components working under high - temperature, high - pressure, and high - wear conditions, such as the components of aero - engines and the valve sealing surfaces in the petrochemical industry.

   • Iron-based self-fluxing alloy powder: Based on iron as the matrix, adding elements such as nickel, carbon, boron, and silicon. This type of powder has a low cost, good wear resistance, and certain corrosion resistance, and can be used for some parts that are cost - sensitive and require high wear resistance, such as the guides of ordinary machine tools and agricultural implements for repair and strengthening.

   
   

2. Ceramic powder

   • Alumina (Al₂O₃) powder: Alumina ceramic powder has the characteristics of high hardness, good wear resistance, and strong chemical stability. In laser cladding, it can form a hard ceramic coating on the metal surface, significantly improving the wear resistance and corrosion resistance of parts. It is commonly used in the manufacture of cutting tools, molds, and mechanical components that require high wear resistance and chemical corrosion resistance.

   • Zirconia (ZrO₂) powder: Zirconia ceramic powder has good toughness and high strength, as well as excellent thermal insulation performance and chemical stability. It can be used in the preparation of thermal barrier coatings, such as the thermal barrier coatings of aero - engines, which can effectively reduce the temperature of high - temperature components and improve their service life.

   • Carbide powder: Including tungsten carbide (WC), titanium carbide (TiC), etc. Tungsten carbide has extremely high hardness and excellent wear resistance and is commonly used in the manufacture of high - performance wear - resistant coatings; titanium carbide has good corrosion resistance and electrical conductivity and can be used to prepare coatings with wear resistance, corrosion resistance, and special electrical properties.

   
   

3. Composite powder

   • Metal - ceramic composite powder: Mixing metal powder and ceramic powder in a certain proportion, it has the advantages of both the toughness of metal and the hardness and wear resistance of ceramics. For example, in the nickel - aluminum - alumina composite powder, during the laser cladding process, the metal phase can form a continuous bonding phase, making the coating have good toughness and bonding strength, while the ceramic phase provides high hardness and wear resistance. It is commonly used in the manufacture of surface coatings for parts that need to bear large loads and require high wear resistance.

   • Metal - metal composite powder: Powders of different metal elements are mixed in a specific proportion to meet special performance requirements. For example, mixing nickel - chromium alloy powder with molybdenum powder can obtain a coating with good high - temperature resistance and wear resistance, which is suitable for components working in high - temperature environments, such as components in the furnace and high - temperature bearings.

   
   

II. Classification by particle size

1. Coarse powder

   • The particle size range is generally between 53μm - 150μm. Coarse powder has a larger particle size and can form a thicker coating during the laser cladding process. It is suitable for applications with high requirements for coating thickness, such as the repair and reinforcement of large structural parts. Due to the larger particles, coarse powder may require higher laser power and a slower scanning speed during cladding to ensure that the powder can be fully melted and form a uniform coating.

   
   

2. Fine powder

   • The particle size is usually less than 53μm. Fine powder has a smaller particle size and a larger specific surface area, which can better absorb laser energy and form a more uniform and dense coating. Fine powder is suitable for preparing thin coatings or precision parts with high requirements for coating quality, such as the surface treatment of optical instrument components, electronic components, etc. When using fine powder for laser cladding, it is necessary to precisely control the laser parameters and powder feeding amount to avoid defects in the coating.

   
   

3. Classification by function

1. Wear-resistant coating powder

   • This type of powder is mainly used to improve the wear resistance of the part surface. The above-mentioned nickel-based, cobalt-based, and iron-based self-fluxing alloy powders, as well as carbide powders, etc., all belong to the category of wear-resistant coating powders. By forming a coating with high hardness and good wear resistance on the part surface, they can effectively reduce the wear of the part during the friction process and extend the service life of the part.

   
   

2. Corrosion-resistant coating powder

   • The powders used to prepare corrosion-resistant coatings mainly include nickel-based and cobalt-based self-fluxing alloy powders, as well as some alloy powders containing corrosion-resistant elements. These powders can form a dense protective film on the part surface, preventing the contact between the external corrosion medium and the part substrate, thereby improving the corrosion resistance of the part.

   
   

3. High-temperature-resistant coating powder

   • Powders with excellent high-temperature performance, such as zirconia and nickel-chromium alloy, can be used to prepare high-temperature-resistant coatings. These coatings can maintain good stability and mechanical properties in high-temperature environments, preventing the part from deforming, oxidizing, etc. under high-temperature conditions. They are suitable for parts working in high-temperature environments, such as engine components in the aerospace field and high-temperature furnaces in the metallurgical industry.

   
   

4. Thermal barrier coating powder

   • Thermal barrier coating powders represented by zirconia mainly function to reduce the surface temperature of parts and improve the thermal shock resistance of parts. In high - temperature working equipment such as aero - engines, thermal barrier coatings can effectively isolate high - temperature combustion gases from the part substrate, protecting the parts from high - temperature erosion and extending the service life of the parts.