Grit Blast Assisted Laser Milling/Grooving of Metallic Alloys

Laser machining and milling of metallic alloys and ceramics have been previously carried out by either direct vaporisation or assist gas ejection of laser-melted materials. For certain metallic materials, due to the high viscosity of the materials in the molten state, it is difficult to achieve a clean cut. Recast and heat affected zones are normally formed. This paper reports a hybrid process combining a grit blasting and laser melting for the milling and grooving of stainless steel, mild steel and titanium alloys. The work shows that up to 100% increase in material removal rate and 15% reduction in the heat affected zone size can be achieved compared with a gas jet assisted laser machining process under the same operating conditions. Surface roughness has been reduced by 60%. The effect of particle injection angle, direction on material removal rate is presented. A critical particle injection angle is established.