A Comparison between Different Materials Based on Transition Metal Oxides as Additivesfor Laser Bonding on Stainless Steel
Keywords:Lasers, laser machining, laser bonding, transition metal oxides
AbstractIn this work, a new modification of the laser bonding is considered. Only one specific transition metal oxide is used to create an additive coating on a stainless surface. The following materials have been selected for comparative analysis: MoO3, WO3 and a commercial laser bond ink produced by TherMark. Temperatures over 2,000 K at the focal spot, with a very steep temperature increasing front of 107 K/s and spatial gradients of 107 K/m, have been evaluated. The mechanical properties of the coating have been studied by ramp scratch and Vickers hardness tests. The structural state and adhesive properties have been studied by X-ray diffraction (XRD) and Raman spectroscopy. A spectrophotometer has been used to estimate the contrast. The experimental results show a hard coating with excellent adhesion to the substrate with a thickness of several m. The presence of intermediated oxides has been detected, which is an indication of oxidation processes. The good adhesion is explained by a chemical bond between the oxide and the substrate.