Archive: Oct 2021

Introduction to the Laser Cladding Process

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Laser cladding—also referred to as laser metal deposition or Laser weld overlay—is a manufacturing technique used to add metal material to the surface of a component. It is generally used to create a protective coating that increases the functionality of the part or product. However, it can also be used to repair worn or damaged surfaces.

The following blog post provides an overview of the laser cladding process, outlining how it works, typical applications, materials used, and key advantages.

How Does the Laser Cladding Process Work?

As suggested by the name, the laser cladding process involves the use of a laser. The laser scans across the surface of the workpiece, creating melt pools in targeted areas. At the same time, a stream of metallic powder or wire is introduced to the targeted areas, which allows the laser to melt the material. The short exposure time reduces the amount of heat and therefore the heat affected zone and enables the workpiece and coating material to cool quickly. The result is a metallurgically bonded coating layer that is tougher than one created using the thermal spray coating method and safer to create than one made through the hard chromium plating method.

Applications of the Laser Cladding Process

Since the laser cladding process can add protective coatings and restore worn/damaged surfaces, it finds use in many industries. For example:

  • In the construction industry, it is used to coat various machines and systems to protect them against corrosion, impact, and wear. The created coatings help extend the service life of the equipment, reducing repair and replacement costs for construction companies.
  • In the oil and gas industry, it is used to coat cutting and drilling tools. These components are regularly subjected to stresses that can reduce their service life without proper wear protection. The laser clad process increases the surface durability of the tooling, allowing it to withstand long-term use.
  • In the mining industry, it is used to coat hydraulic cylinders. The coatings on hydraulic cylinders are highly susceptible to corrosion in mining facilities, which can lead to leaks. Coatings created through the laser cladding process are longer-lasting than ones made through the chrome plating process, which can lead to significant cost savings over the years.

What Materials Can Be Used With the Laser Cladding Process?

The laser cladding process can be performed with a broad selection of metals, including, but not limited to, the following:

  • Aluminum alloys
  • Cobalt alloys
  • Copper alloys
  • Nickel (self-fluxing) alloys
  • Stainless steels
  • Superalloys
  • Titanium alloys
  • Tool steels

Advantages of Laser Cladding

There are many advantages to using laser cladding over other coating methods. For example:

  • It allows for the precision positioning of coating materials, enabling coaters to target specific areas on the component.
  • It creates layers that are more impact resistant than ones made through the thermal spray coating method, which can lead to better protection for components.
  • It produces layers with little to no porosity, which creates denser (>99.9% density) coatings.
  • It requires relatively low heat input, generating a narrower heat-affected zone (HAZ).
  • It generates minimal distortion in the workpiece, reducing the need for post-coating processing.
  • It accommodates the use of laser power modulation technology, which allows for better thermal control.

Learn More About Laser Cladding From Titanova

Want to learn more about the laser cladding process? Ask the experts at Titanova! We have extensive experience providing laser processing solutions, including laser cladding, to customers across a wide range of industries. Our team can answer any questions and address any concerns you may have about the process.

Do you require a laser cladding partner for your next project? We are here to help! Equipped with customized diode lasers, we can create the thinnest and purest weld overlay possible. Check out our laser cladding service page to learn more about our capabilities.

Hardfacing Methods

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Hardfacing delivers a wear-resistant and hard coating of material on the surface of a worn component or a new component that will be subject to wear. There are various methods that can be used to apply the hardfacing layer. Common methods include:

  • Arc Welding
  • Oxygen-Acetylene
  • Thermal Spraying
  • Diode Laser Hardfacing

The different hardfacing techniques provide different results to suit a range of applications. This blog will describe the various hardfacing methods to help you determine the ideal method for your application or industry.

Laser WC Hardfacing Mixing Plow

Laser WC Hardfacing Mixing Plow

Types of Hardfacing Methods

There are various methods for hardfacing, which include:

Diode Laser Hardfacing

Diode laser hardfacing can increase lifespan and reduce wear of material handling components. The coating is extremely wear-resistant, relying on a laser to weld a thin metal layer embedded with super hard particles. Diode laser hardfacing produces a thin, smooth, and uniform coating. It provides a hard particle density of up to 75% and prevents burning carbides with low heat application.

Submerged Arc Welding (SAW)

SAW relies on flux to unite slag and protective gases into the weld pool. When welding, an arc forms between the flux and the workpiece surface through a continuously fed wire electrode. SAW provides excellent deposition rates, deep penetrating welds, and versatility to perform indoors and outdoors. The leftover flux can also be recycled using a flux recovery system.

Flux Cored Arc Welding (FCAW)

FCAW uses a continuously fed tubular flux-filled electrode and requires constant voltage. It is not ideal for all metals but provides excellent penetration and a high deposition rate. FCAW is suitable for any welding position and allows for manual, automatic, and semi-automatic operations. It is ideal for construction applications due to its mobility and speed.

Shielded Metal Arc Welding (SMAW)

This manual arc welding process relies on a covered flux consumable metal electrode that shields the weld pool. It forms an arc between the electrode and the metal substrate using an electric current. When laying the weld, the flux coating disintegrates and creates a layer of slag and shielding gas to protect the weld while cooling. SMAW has lower deposition rates than other welding techniques but works with a range of metals and alloys. It also allows for diesel or gas power, making it highly portable and suitable for remote regions.

Gas Metal Arc Welding (GMAW)

GMAW or MIG welding relies on a welding gun with a consumable wire electrode and a shielding gas. The process is automatic or semi-automatic and typically uses a constant voltage. While it is unusable for overhead and vertical welds, it requires little cleaning post-weld thanks to its low slag generation and provides high deposition rates with low consumable costs.

Gas Tungsten Arc Welding (GTAW)

GTAW or TIG welding creates an arc between the workpiece and a non-consumable electrode, and an inert gas barrier is formed to protect the welding pool. It has lower deposition rates than other methods but leaves a clean finish without producing slag. GTAW also offers a high range of flexibility, allowing welding to be manually or automatically performed in any position and with a wide range of metals.

Thermal Spraying

Thermal spraying is a hardcoating method that sprays heated or melted materials onto a surface. It relies on chemical or electrical heating to spread a coating up to several millimeters thick over a large area with a higher deposition rate than other methods. Thermal spraying works with various material surfaces and does not heat the surface significantly, making it suitable for coating flammable materials.

Oxygen-Acetylene

Oxygen-acetylene hardfacing is a relatively simple method for those familiar with welding. It is not ideal for coating large components, but it provides low weld deposit dilution and provides enhanced control of the deposit shape. Oxygen-acetylene also delivers lower thermal shock with a slower heating and cooling process.

Metal Compatibility With Hardfacing

Various metals are compatible with hardfacing. The primary requirement for a prospective material to be compatible with hardfacing is a carbon content lower than 1%. Low-alloy steels and carbon steels are typically compatible, but high-carbon alloys may require a special buffer layer.

The following metals offer compatibility with hardfacing:

  • Nickel-Based Alloys
  • Cast Iron and Steel
  • Stainless Steel
  • Copper-Based Alloys
  • Manganese Steel

Partner With Titanova for Your Laser Hardfacing Needs

Industrial hardfacing can be applied to various materials using diode lasers, thermal spray, and several welding methods. Each method provides unique benefits and can reliably apply a hardfacing coating on a range of metals. Learn more about Titanova’s laser hardfacing capabilities and contact us to speak with a representative today.