Laser machining efficiency and quality are closely related to gas pressure, nozzle geometry, and standoff distance. Modeling studies of laser machining rarely incorporate gas effects in part because of the complex structure and turbulent nature of jet flow. In this paper, the interaction of a supersonic, turbulent axisymmetric jet with the workpiece is studied. Numerical simulations are carried...

In this research, finite element analysis of the conventional drilling and vibration assisted drilling is carried out. The ABAQUS software is employed for FE analysis. The Johnson-Cook models for both plastic deformation and damage are employed for FE simulation.The results of the FE analysis are then verified with experimental results in both conventional and vibration assisted drilling on Al ...

The paper presents a novel method for monitoring and estimating the depth of a laser-drilled hole using machine vision. Through on-line image acquisition and analysis in laser machining processes, we could simultaneously obtain correlations between the machining processes and analyzed images. Based on the machine vision method, the depths of laser-machined holes could be estimated in real time....

High-power, nanosecond-pulse Q-switch laser processing has become commonplace in both existing and emerging high-tech industries. As these industries grow and mature, there is increased need for low-cost, high-quality manufacturing techniques. This translates to a need for increasingly precise and efficient laser processing capabilities. In this work, Newport/Spectra-Physics’ latest Q-switch di...

Quality improvements in laser machining have been achieved by a newly developed model-based optimisation strategy. The speci®c aims of such efforts are to assure machining quality right up to boundaries or pre-machined sections, which are inherent in intricate part geometry. Such boundaries frustrate heat-transfer and result in bulk heating of the workpiece. This in turn leads to a degradation ...

Background and Aim: Bleaching can improve the color of restorative materials and resolve problems related to discoloration or color mismatch. This study evaluated the effect of in-office bleaching method in conjunction with two different laser wavelengths on color change of two types of glass-ionomer restorative materials (light-cure and self-cure). Materials and Methods: In this experimenta...