WEAR TESTING MACHINE BY LASER BEAM ABLATION PATENT NO 24013 EGYPTIAN PATENT OFFICE

Wear testing machine by laser ablation has been considered as a new method of wear testing which overcome the problems of old machines and systems. In this case, wear rate has occurred due to ablation by laser beam and test sample transformed from solid state to gas state directly (sublimation) and avoid relative movement and loss of material between sample and disk or plate. The different operation conditions such as temperature, chemicals, environmental conditions and different types of stresses has been considered. The new machine consists of two main parts optical and mechanical parts. The optical parts which include ultraviolet laser source, optical filter, lenses to concentrate the beam and manhole of laser beam to the sample tested in the control room. The mechanical parts includes The insulated chamber , dead weight , variable speed motor, sample holder, temperature and pressure sensor and ph meter. Mechanism of operation depend mainly on Ablation process which is removal of material from the surface of an tested object by vaporization .Ultraviolet laser beam is used as source of energy required for ablation process to avoid thermal effects. The new technique is suitable for all kinds of materials such as metals, alloys polymers, ceramics and composites in any shapes and sizes. The main factors affecting the new techniques are divided into factors related to the laser beam characteristics and factors related to material properties, the material properties include the surface roughness, thermal conductivity, specific heat ,density and mainly latent heat of sublimation.