LaserFusion and Hardening
30/04/2009
LaserFusion and Hardening
AustChrome’s High Powered Direct Diode Laser
(HPDDL) provides customers with a powerful reclamation tool for a diverse
range of applications. The unique design of AustChrome’s laser provides
a wider beam (12mm) than the typical fibre coupled laser system. This wider
beam profile allows AustChrome’s HPDDL to process larger areas quickly;
making it more suited to reclamation and heat treatment processes for larger
components commonly found in the Australian industrial and earthmoving
industries.
AustChrome offers two HPDDL services:
These are:
- LaserFusion: A cladding process designed
to reclaim worn components and improve surface performance.
- Laser Heat Treatment: Surface hardening of
the complete component or specific areas to achieve increased component
performance.
LaserFusion is a reclamation process where
worn areas of components are reclaimed by using alloy powder onto required
areas of a work piece. LaserFusion has significant advantages over traditional
reclamation technologies in both performance, lifetime of the
repair and effect on the base material.
This process uses a High Power Direct Diode
Laser, the only one of its kind in Australia, to fuse Metal/Alloy powder
onto a worn component.
This unique process allows AustChrome to apply
a metallic coating with almost no dilution and very low heat penetration
(equalling low distortion).
The full metallic bond created between the
metal/alloy coating and the base material gives the strongest bond of all
reclamation technologies.
The high bond strength allows the reclaimed
components to withstand point loading, impact and distortion. It also enables
a much thicker build area than thermal spray and electroplating technologies.
This allows AustChrome the ability to reclaim
components previously discarded as unrepairable.
LaserFusion coatings also provide an ideal
surface finish for high surface finish applications, such as hydraulics
rods.
LaserFusion creates a full metallic bond between
the base material (e.g. original component and the coating applied). Thermal
spray or electroplating are mechanical bonds, (whereas LaserFusion is a
metallurgic bond) therefore they will not withstand point loading, impact
or distortion. The major advantage is that LaserFusion coating will delaminate
from the base material as they become fully fussed with the base material
when applied.
Benefits of LaserFusion include
- Small Heat Affected Zone = Less Distortion
- High Quench Rates = Finer Grain Structure
= High Corrosion Potential
- Highly Controllable
The
ability to precisely control temperature and power of the laser means LaserFusion
does not apply as much heat and stress on the base material as with conventional
welding methods. This results in a small heat affected zone from the LaserFusion
process. The result is a coating consisting of almost pure alloy (less
than 2% dilution between the base metal and alloy coat) and very little
to no distortion. There is also very little change in the micro-structure
of the base metal.
LaserFusion also allows for heavier builds over other reclamation technologies.
2mm of build can be laid in one pass through LaserFusion, giving AustChrome
the ability to reclaim areas damaged by heavy wear or scoring both quickly
and accurately.
Laser Heat Treatment
The benefits of heat treatment with HPDDL include:
Selective hardening of materials:
- Both depth and area are possible
Low or negligible distortion:
- Only transforms what needs to be transformed.
- Precision heating and control
Using LaserFusion to reclaim an underground cutter drum. 
Using LaserFusion to reclaim a badly worn Hydraulic Rod. 
Conveyor Pulley Drum with Bearing areas reclaimed by LaserFusion. 
Reaction Hub Face reclaimed using LaserFursion prior to final machining. 
Large Hydraulic Rod being reclaimed using LaserFusion. 
Close up of the Laser head showing Alloy Powder being fed into the Laser Beam. 
A large shaft having its bearing journals reclaimed using LaserFusion