Thermal Spraying

Thermal spraying is a surface engineering process where melted or heated materials are sprayed onto a substrate to form a coating. This technique enhances surface properties such as wear resistance, corrosion protection, thermal insulation, and electrical conductivity. One of the most critical factors for achieving a successful thermal spray coating is the quality and characteristics of the feedstock powder. This is where SLM Metal, a leading manufacturer of metal and iron powders, plays a key role by supplying materials optimized for various thermal spray processes.

What Is Thermal Spraying?

Thermal spraying involves the projection of fine, molten or semi-molten particles onto a surface, where they flatten and rapidly solidify to form a dense, well-adhered coating. The process is typically carried out using high-velocity gas, plasma, electric arc, or combustion flames to heat the feedstock.

Common Types of Thermal Spraying:

1. Plasma Spraying (APS/VPS)

2. High Velocity Oxy-Fuel (HVOF)

3. Wire Arc Spraying

4. Flame Spraying

5. Cold Spraying

Role of SLM Metal Powders in Thermal Spraying

SLM Metal provides a broad portfolio of engineered iron, nickel, cobalt, copper, and alloy powders that are purpose-built for thermal spraying. These powders exhibit excellent flowability, controlled particle morphology, and chemical stability—ensuring high-quality coatings in even the most demanding applications.

Process Overview

1. Powder Selection
   High-performance coatings begin with the right material. SLM Metal’s powders are available in various compositions including:

   • Iron-based powders: For wear resistance and cost-effective overlays.

   • Nickel-based alloys: For corrosion and high-temperature resistance.

   • Cobalt alloys: For high wear and impact performance.

   • Copper and bronze powders: For electrical and friction-reducing coatings.

2. Powder Injection
   The powder is injected into a thermal energy source (flame or plasma jet), where it is heated and propelled toward the substrate.

3. Particle Impact and Solidification
   Upon impact, the particles flatten and bond mechanically or metallurgically with the surface, building up a coating layer by layer.

4. Post-Processing (if required)
   Coatings may be ground, machined, or sealed to enhance performance and finish.

Key Technical Parameters

Applications of Thermal Spraying

Advantages of Using SLM Metal Powders in Thermal Spraying

• High sphericity: For efficient powder flow and reduced clogging.

• Controlled particle size: Ensures optimal melting and coating thickness.

• Customized compositions: Tailored to meet specific customer and industry requirements.

• Batch-to-batch consistency: Critical for regulated industries such as aerospace and medical.

• Excellent sinterability: Beneficial when thermal sprayed coatings are further densified via post-processing.

Advanced Material Solutions by SLM Metal

SLM Metal continuously invests in R&D and powder engineering, offering specialized materials for advanced thermal spraying methods:

1. Cold Spray Applications

Cold spray requires ultra-fine, ductile powders like pure iron, aluminum, copper, and nickel, all of which are supplied by SLM Metal with tight tolerance specifications and oxygen control.

2. High-Velocity Oxy-Fuel (HVOF)

For dense, wear-resistant coatings, SLM Metal provides tungsten carbide-based and FeCrAl powders with optimized density and hardness.

3. Plasma Spraying

SLM Metal’s ceramic-metal composite powders and high-melting-point alloys support critical plasma spray applications where thermal barrier or high-wear performance is required.

Thermal spraying is a highly adaptable and efficient surface modification technique that enables engineers to enhance component performance across a wide range of industries. The reliability and effectiveness of the coating depend heavily on the quality of the feedstock powder.

SLM Metal, as a trusted supplier of premium-grade metal and iron powders, plays a crucial role in advancing thermal spray technology. Whether it’s through providing powders for high-temperature resistance, corrosion protection, or electrical conductivity, SLM Metal ensures superior coating performance through precision-engineered materials.

By combining cutting-edge powder technology with decades of metallurgical expertise, SLM Metal is powering the next generation of thermal spray applications