PTA Overlays

Taskmaster Technologies offers advanced Plasma Transferred Arc (PTA) welding for high-performance hardfacing and overlay applications.

The Taskmaster PTA Welding System is a precise, high-energy, inert-gas welding process that produces exceptionally high-quality deposits with minimal dilution and negligible distortion of the base material. Unlike thermal spray processes that rely on a mechanical bond, PTA creates a true metallurgical (welded) bond, providing superior resistance to corrosion, erosion, abrasion, and thermal shock.

A wide range of overlay alloys is available to suit virtually any application. Because the system utilizes metal powders as the feedstock, nearly any alloy system can be applied, including:

• Chrome carbide
• Tungsten carbide
• Nickel-based alloys
• Cobalt-based alloys
• Stainless steels
• Emerging and developmental ceramic-based powders

Precise control of application parameters results in dilution levels of only 3–7%, compared to conventional welding processes that can reach dilution levels of up to 40%. The process produces a narrow heat-affected zone, minimizing undesirable metallurgical changes in the substrate and preserving the intended performance of both the base material and the overlay.

The Taskmaster PTA welding system is capable of deposition rates of up to 20 lb/hr and is equipped with automated manipulation to accommodate components with complex geometries and tight dimensional tolerances.

When compared to laser surfacing, PTA technology delivers significantly higher productivity with comparable deposit quality and substantially lower overall processing costs.

Typical applications include:

• Mining, crushing, rolling, road-building, and tunneling equipment
• Extruder screws
• Valves, gates, seats, and bore liners
• Power generation components
• Cutting tools (milling cutters, broaches, knives)
• Process equipment for ceramics and cement production
• Plastic molds and forging dies
• Pulp and paper industry equipment
• Agricultural equipment

Non-Magnetic Plasma Transfer Arc Overlays

Through decades of hands-on industry experience and technical expertise, we have developed proprietary processes and tailored materials that deliver industry-leading results on non-magnetic steels. Our approach carefully controls heat input and base material temperature, minimizing cracking and reducing premature fatigue failure.

Taskmaster Standard Non-Mag PTA Advantages

• Bonding Mechanism: Metallurgical weld bond, verifiable via ultrasonic testing
• Matrix Alloy: Proprietary nickel-based, non-magnetic, corrosion-resistant alloy
• Matrix Hardness: 30–35 HRC — tough and impact resistant
• Tungsten Carbide Particles: Provide extreme wear and erosion resistance, 2200–2400 HV
• Magnetic Properties: Non-magnetic, verified by magnetic permeability testing
  o Results below 1.010 are acceptable; values below 1.005 are common
• Density: 0.400 lbs/in³ (11.1 g/cm³)

Hardbanding

For applications such as hardbanding on non-magnetic tools like drill collars, our overlays are engineered with precise material ratios to ensure the hard band wears at a controlled rate while protecting the surrounding base material. Incorrect ratios can cause the hard band to outlast the base material, leading to the formation of “mud rings.” While these can be repaired, the original material’s integrity is never fully restored, resulting in additional downtime and replacement costs. By optimizing the composition of our overlays, Taskmaster ensures maximum tool life and cost efficiency, preserving the base material and preventing unnecessary repairs.

Material composition is customized based on application. For higher wear and lower impact applications, the tungsten carbide content can be increased relative to the matrix alloy to maximize performance.

Traditional Weld Overlay (GTAW, GMAW, SMAW)

While PTA welding provides the highest performance for hardfacing, traditional weld overlay processes—GTAW (TIG), GMAW (MIG), and SMAW (Stick)—have made significant advancements in recent years. Their lower equipment setup costs make them a cost-effective and widely used option across many industries.

At Taskmaster, we have integrated the MIG welding process with custom-designed automation equipment, delivering high-quality results with predictable repeatability.

Materials and Applications

We can apply a broad range of common alloys, including:

• Aluminum Bronze
• Chrome Carbide
• Tungsten Carbide Composites
• Nickel- or Cobalt-based alloys
• Low-alloy Manganese products

Flexible Application Options

• Automated Overlays: Ideal for consistent coverage and high-volume parts
• Manual Overlays: For small, odd-shaped, or hard-to-reach areas where automation is not practical
• Hybrid Approaches: Traditional welded overlays can be combined with PTA to ensure full coverage, even in areas difficult to access with automated PTA equipment

This flexibility allows us to optimize performance and cost efficiency for each specific application.

Example: Welded Aluminum Bronze coating applied to an alloy steel part, finished at ¼ inch thickness.