The specialist team carried out the repair, making quality checks at each stage before going forward to the next; the process beginning with the determination of the full extent of the cracking by non-destructively testing the area around the visible crack. The team determined the extent of the crack and machined away the defective material.
Work was carried out using the Trumpf DMD 505 laser deposition machine at TWI. By varying machine settings such as laser power, deposition speed, laser spot size and powder flow rate, it was possible to determine a combination of parameters that produced a defect free deposit and a strong fusion bond with the component. This was validated by sectioning and inspecting the microstructure of the deposited material produced on the sample supplied by ARC.
The team then manufactured a cylindrical tubular sleeve using the laser deposition machine and the selected powder. The manufactured sleeve was press fitted into the bore of the suspension link and formed a base for further laser deposition workto fill the gap produced by the removal of the cracked material.
Using deposition parameters determined previously, TWI used laser deposition to replace the material removed by machining. The laser deposited material fused onto the internal sleeve and onto the sides of the machined recess, ensuring that the sleeve was securely fusion bonded to the original material at the edges of the repair.
The internal sleeve was then removed by machining but without touching the original bore diameter. This left a crack free repair of the landing gear component.
Please email contactus@twi.co.uk for further information or investigate laser processing and laser metal deposition at TWI.