Emerald Group Publishing Limited
Metallisation launches new laser cladding system
Article Type: New materials and equipment From: Anti-Corrosion Methods and Materials, Volume 61, Issue 6
Metallisation has launched a new laser cladding system, MET-CLAD, which has further enhanced Metallisation’s diverse range of surface coating equipment.
Laser cladding, a process that falls into the range of hard-facing solutions, can be used to increase corrosion resistance, wear resistance or impact performance of metallic components, using a method of applying a fully dense, metallurgically bonded and virtually pure coating.
The Metallisation MET-CLAD system has been developed as a result of a collaboration with laser cladding specialists, LASE Ltd., based in South Wales. Metallisation, experts in machine building, offers laser cladding systems and technical support to industry, supported by LASE Ltd.’s extensive laser cladding expertise and experience.
Metallisation has supplied its first MET-CLAD system to LASE, at its South Wales factory, where it has been successfully integrated into the production facility. The new system is also flexible enough to be taken on-site if the size of the customer’s component prohibits transportation to the South Wales facility.
The laser cladding process utilizes a precisely focused high power laser beam to create a tightly controlled weld pool into which a metallic powder is applied. The powder is carried by a stream of inert shielding gas, which is blown coaxially through the laser beam. The highly accurate nature of the laser beam allows fully dense cladding with minimal dilution and a perfect metallurgical bond. The number of coatings that can be applied are vast, the composition of which can be designed to combat failure mechanisms associated with each component.
The Laser cladding process produces a coating with a higher level of purity than other traditional welded hard facing processes. The coating properties, and the high level of purity, will maximize the working life of components and minimize downtime. The very low heat input, associated with a laser, minimizes distortion and results in a refined microstructure. Due to the high level of accuracy and control laser cladding enables the cost effective application of high performance alloys to tackle a wide range of engineering issues.
The MET-CLAD laser cladding control console, developed and built by Metallisation, is at the heart of the system, as it provides integration and control of the complex component parts. To apply a laser clad coating the cladding head has to be fed the appropriate with four key things; a laser beam, process gasses, powder and cooling water. This is where the MET-CLAD system steps in with a very simple to use control system and touch-screen human–machine interface (HMI). The MET-CLAD control system is based on the tried and tested Metallisation high velocity oxygen fuel (HVOF) and plasma control concept. The control interface for production operations is simple, but it can be drilled down to a great level of complexity for coating development. Repeatable operations are easily programmed or they can be linked to a barcode system for even simpler programming. The process gases are mass flow controlled for repeatability of the coating process.
One of the major benefits of laser cladding is the ability to finely control the heat input to the substrate and the coating material, which allows a deposit of a two-phase Metal Matrix Composite Structure. This means the coating can have a softer, lower melting point material (the matrix) where a harder wearing, higher melting point material (the hard phase) is suspended.
The matrix material is typically a nickel-based alloy, which provides a tough, ductile and impact resistant surface, while being wear resistant at elevated temperatures. The reinforcing hard phase is typically tungsten carbide, but can also be titanium carbide or chromium carbide. The fine control of the heat input allows the matrix to be completely melted, alloyed and bonded to the substrate surface. The carbide particles remain un-melted and are distributed evenly through the matrix, resulting in an extremely strong wear and impact resistant coating.