Abrasive jet machining
This clean gas sends to drier, which absorb moisture from it. This system consists, compressor, air filter and drier.
Abrasive jet machining
The nozzle increases the velocity of the mixture at the expense of its pressure. When an abrasive particle like Al2O3 or SiC having sharp edges hits a brittle and fragile material with a high speed, it makes dent into the material and lodges a small particle from it by a tiny brittle fracture. Material removal rate and its estimation Knowledge of material removal rate MRR is beneficial for selecting process parameters and choosing feed rate of the nozzle. The lodged out or wear particle is carried away by the air or gas. Hopper: In AJM, usually circular hopper with gradual compression is employed for continuously supplying fresh abrasive to the mixing chamber. Nozzle: It forces the abrasive jet over the workpiece. Flow regulating valves: These valves controls volume flow rate of carrier gas in order to maintain constant mixing ratio. Abrasive jet machining is a non-traditional machining process which is mostly used in machining of hardened metals. It consists of gas supply system compressor , filter, pressure regulator, mixing chamber, nozzle assembly and the work holding device. It also facilitates accurate estimation of productivity, delivery time as well as production cost. Moreover, increased gas flow rate gives the provision for utilizing higher abrasive flow rate, which can improve productivity. This gives easy, accurate and precise control and is suitable for cutting intricate profiles and contours. The process can be easily controlled to vary the metal removal rate which depends on flow rate and size of abrasive particles. It also enhances MRR.
A vibrator is used to control the feed of the abrasive powder. It is used for machining brittle and heat sensitive material like glass, quartz, sapphire, mica, ceramic etc. Important process parameters include i abrasive particles—its shape, size, strength, material and flow rate; ii carrier gas—its nature, composition, flow rate, pressure and temperature; iii abrasive jet—mixing ratio, striking velocity, impingement angle and stand-off distance; iv nozzle—its profile and inner diameter; and v work material—its mechanical properties and stress concentration.
In the mixing chamber, the abrasive is allowed to flow into the gas stream. Hopper: Hopper is used for feeding the abrasive powder.
Water jet machining pdf
Various components of AJM set-up and their functions. The feed motion can be given either to the work holding device or to the nozzle. Abrasive materials have varying strength or hardness. There the density and pressure of gas increases. Choosing nozzle material is another decisive factor from economic point of view. AJM performance is usually assessed by analyzing three output responses, namely i material removal rate MRR , ii surface roughness and accuracy of machined feature, and iii nozzle life or nozzle wear rate. Its working process can be easily summarized into following point.
Equipment for abrasive jet machining Air compressor: It compresses the carrier gas to a pressure of 15 — 20bar. Higher SOD causes spreading of jet and thus its cross-sectional area increases with the sacrifice of jet velocity.
based on 3 review