07-10-2017, 01:10 PM
Abrasive Blast Machining (AJM), also known as abrasive micro-blasting, pencil blasting and microabrasive blasting, is an abrasive blasting process that utilizes high speed gas driven abrasives to erode the workpiece material . Common uses include cutting heat-sensitive, brittle, thin or hard materials. Specifically it is used to cut intricate shapes or form specific edge shapes.
The material is removed by fine abrasive particles, generally about 0.001 inches (0.025 mm) in diameter, driven by a high velocity fluid stream; common gases are air or inert gases. Pressures for the gas range from 25 to 130 psig (170-900 kPag or 4 bar) and speeds can be as high as 300 m / s (1,000 km / h).
The main advantages are its flexibility, low heat production and the ability to machine hard and brittle materials. Its flexibility is due to its ability to use hoses to transport gas and abrasive to any part of the workpiece. One of the main disadvantages is its slow rate of material removal; for this reason it is generally used as a finishing process. Another disadvantage is that the process produces a conical cut.
In the abrasive jet machining process, a focused vapor of abrasive particles (size 10 to 40 micrometers) carried by gas or high pressure air is made at a rate of about 150 to 300 m / s, shock on the work surface through a nozzle, and the working material is eliminated by erosion by the high speed abrasive particles. The inside diameter (ID) of the nozzle through which abrasive particles flow is approximately 0.18 to 0.80 mm and the separation distance (i.e., the distance between the nozzle tip and the workpiece) is maintains approximately 0.3 to 20.0 mm. The process can be easily controlled to vary the rate of metal removal depending on the flow rate and the size of the abrasive particles. This process is most suitable for the machining of superalloys and refractory materials, as well as for machining thin sections of hard materials and making intricate hard holes. The cutting action is cold because the carrier gas serves as a refrigerant.
The material is removed by fine abrasive particles, generally about 0.001 inches (0.025 mm) in diameter, driven by a high velocity fluid stream; common gases are air or inert gases. Pressures for the gas range from 25 to 130 psig (170-900 kPag or 4 bar) and speeds can be as high as 300 m / s (1,000 km / h).
The main advantages are its flexibility, low heat production and the ability to machine hard and brittle materials. Its flexibility is due to its ability to use hoses to transport gas and abrasive to any part of the workpiece. One of the main disadvantages is its slow rate of material removal; for this reason it is generally used as a finishing process. Another disadvantage is that the process produces a conical cut.
In the abrasive jet machining process, a focused vapor of abrasive particles (size 10 to 40 micrometers) carried by gas or high pressure air is made at a rate of about 150 to 300 m / s, shock on the work surface through a nozzle, and the working material is eliminated by erosion by the high speed abrasive particles. The inside diameter (ID) of the nozzle through which abrasive particles flow is approximately 0.18 to 0.80 mm and the separation distance (i.e., the distance between the nozzle tip and the workpiece) is maintains approximately 0.3 to 20.0 mm. The process can be easily controlled to vary the rate of metal removal depending on the flow rate and the size of the abrasive particles. This process is most suitable for the machining of superalloys and refractory materials, as well as for machining thin sections of hard materials and making intricate hard holes. The cutting action is cold because the carrier gas serves as a refrigerant.