Research On Repair Process Of Manual TIG Filler Wire+Laser Melting Of Die-Casting Dies

Die-casting dies could be easily damaged due to the severe working conditions, affecting the service life of dies. In addition, reproducing the failed moulds may reduce the waste of material and financial resources. Therefore, how to repair failed moulds and extend their service life becomes one of the most concerned topics for material researchers.This paper proposes a new method called manual TIG filler wire + laser melting to solve the low strength of TIG weld, by processing laser melting on the surface layer of TIG weld. A better microstructure performance of the TIG repair-layers is wished by laser melting, so as to get a new method to repair large cracks. After the theoretical analysis, this study prepare the composite repair layer, and use a series of test manners such as scanning electron microscope(SEM), X-ray diffraction analysis(XRD), microhardness test, thermal fatigue crack blocking test, friction-wear test to analysis the strengthening property of the laser melting to the TIG repair layer; then compare the result with the repair property of manual TIG filler wire welding and laser welding with filler wire, and verify the feasibility of the repair process with TIG manual filler wire + laser melting; use the technology in mould repair in the enterprise, observe the service life of the moulds. The experimental results show that the laser melting can effectively refine the surface microstructure of TIG repair layer, reduce the internal stress and improve the plasticity and toughness, this make the thermal fatigue resistance of the repaired zone improve greatly. Under high temperature sliding wear condition, the surface friction coefficient of The TIG + laser melting composite sample is small, the wear quantity is about 1/2 to the TIG manual filler wire and the laser filler wire sample, show excellent wear resistance. The service life of moulds repaired by TIG manual filler wire + laser melting increased by 20%.