04-02-2016, 03:43 PM
Introduction
A stream of abrasive grains (Al2O3 or SiC) is carried by high pressure gas or air (compressed).Impinges on the work surface at very high velocity through a nozzle of 0.3 to 0.5 mm diameter. Sand Blasting (SB) - a similar process The major differences between are SB and AJM smaller diameter abrasives a more finely controlled delivery system Material removal – by mechanical abrasion action of the high velocity abrasive particles. Best suited for hole drilling in superhard materials. Typically used to cut, clean, peen, deburr, deflash and etch glass, ceramics and other hard materials.
Machining System – Contd.
A gas (Nitrogen, CO2 or air) is supplied at 2 – 8 kg/cm2 Oxygen should never be used. (because, it causes violent chemical action with the workpiece chips or abrasive particles).Gas passes through a mixing chamber after filtration and regulation.In the mixing chamber, abrasive particles (10 – 40 m) are present and vibrated at 50 Hz.Amplitude of vibration – to control the feed rate of abrasives.(Gas + abrasives) - passed through a 0.45 mm diameter tungsten carbide nozzle at a speed of 150 – 300 m/s.The nozzle is directed over the area to be machined.