Abrasive jet machining
ABRASIVE JET MACHINING
INTRODUCTION:-
IT IS A PROCESS OF MATERIAL REMOVAL THROUGH THE ACTION OF A FOCUSED STREAM OF FLUID WITH ABRASIVE PARTICLES. IT IS ESPECIALLY USED FOR MACHINING SUPER ALLOYS, CERAMICS; GLASS AND REFRACTORY MATERIAL. IT IS ONE OF THE NON-POLLUTING METHODS AVAILABLE FOR MACHINING HARD MATERIALS TO PRECISION DETAILS. IN ABRASIVE WATER JET MACHINING THE ABRASIVE PARTICLES UTILIZES WATER JETS TO ACCELERATE OR DECELERATE THEIR SPEEDS DEPENDING UPON THE TYPE OF MATERIAL TO BE MACHINED. THIS MACHINING PROCESS CARRIES AN ADDITIONAL ADVANTAGE FOR IT CANNOT BE REACTIVE WITH ANY OF THE JOB MATERIAL AND FOR IT'S VERSATILITY THAT ANY MATERIAL, HOW MUCH HARDER IT IS CAN BE MACHINED. THE BEST OF ALL NO TOOL CHANGES ARE REQUIRED, FIXTURES TO HOLD THE WORK PIECE ARE MINIMAL IN AJM.IT CAN BE USED TO VIRTUALLY MACHINE ANY PARTS WITH ANY INTRICACIES OF SHARP CORNERS OR TIGHT RADIUS AT CORNERS ETC.
THE MATERIAL WHICH ARE BEING MACHINED BY THIS PROCESS DO NOT EXPERIENCE ANY HARDENING DUE TO PROCESS BECAUSE HEAT GENERATED IS VERY LESS. ALSO, SINCE MAJOR CUTTING FORCES ARE DIRECTED IN DOWNWARD DIRECTION IT CAN BE USED TO MACHINE MATERIALS WITH VERY SMALL WALL THICKNESS. THE DEPTH OF CUT OR THICKNESS OF PART TO BE MACHINED IS A FUNCTION OF SPEED AND BEST MATERIAL MACHINING IS OBTAINED FOR THICKNESS LESS THAN 1INCHES.
METAL REMOVAL MECHANISM:-
ABRASIVE JET MACHINING UTILIZES THE PRESSURE OF FLUID STREAM TO REMOVE MATERIAL FROM THE SURFACE OF THE JOB. WHEN USING AIR AS A MEDIUM THE MIXTURE OF AIR AND ABRASIVES ARE ALLOWED TO IMPINGE ON THE WORK SURFACE AT ABOUT 200 TO 400M/S THROUGH THE NOZZLE AND WORK MATERIAL IS ERODED BY THE HIGH VELOCITY ABRASIVE PARTICLES. THE INSIDE DIAMETERS OF THE NOZZLE ARE ABOUT 0.04MM AND STANDOFF DISTANCE IS KEPT ABOUT 0.7 TO1.0MM. THE PROCESS CAN BE EASILY CONTROLLED TO VARY THE METAL REMOVAL RATE WHICH DEPENDS ON FLOW RATE AND SIZE OF ABRASIVE PARTICLES .THE CUTTING ACTION IS COOLED BECAUSE THE CARRIER GAS SERVES AS A COOLANT.
INTRODUCTION:-
IT IS A PROCESS OF MATERIAL REMOVAL THROUGH THE ACTION OF A FOCUSED STREAM OF FLUID WITH ABRASIVE PARTICLES. IT IS ESPECIALLY USED FOR MACHINING SUPER ALLOYS, CERAMICS; GLASS AND REFRACTORY MATERIAL. IT IS ONE OF THE NON-POLLUTING METHODS AVAILABLE FOR MACHINING HARD MATERIALS TO PRECISION DETAILS. IN ABRASIVE WATER JET MACHINING THE ABRASIVE PARTICLES UTILIZES WATER JETS TO ACCELERATE OR DECELERATE THEIR SPEEDS DEPENDING UPON THE TYPE OF MATERIAL TO BE MACHINED. THIS MACHINING PROCESS CARRIES AN ADDITIONAL ADVANTAGE FOR IT CANNOT BE REACTIVE WITH ANY OF THE JOB MATERIAL AND FOR IT'S VERSATILITY THAT ANY MATERIAL, HOW MUCH HARDER IT IS CAN BE MACHINED. THE BEST OF ALL NO TOOL CHANGES ARE REQUIRED, FIXTURES TO HOLD THE WORK PIECE ARE MINIMAL IN AJM.IT CAN BE USED TO VIRTUALLY MACHINE ANY PARTS WITH ANY INTRICACIES OF SHARP CORNERS OR TIGHT RADIUS AT CORNERS ETC.
THE MATERIAL WHICH ARE BEING MACHINED BY THIS PROCESS DO NOT EXPERIENCE ANY HARDENING DUE TO PROCESS BECAUSE HEAT GENERATED IS VERY LESS. ALSO, SINCE MAJOR CUTTING FORCES ARE DIRECTED IN DOWNWARD DIRECTION IT CAN BE USED TO MACHINE MATERIALS WITH VERY SMALL WALL THICKNESS. THE DEPTH OF CUT OR THICKNESS OF PART TO BE MACHINED IS A FUNCTION OF SPEED AND BEST MATERIAL MACHINING IS OBTAINED FOR THICKNESS LESS THAN 1INCHES.
METAL REMOVAL MECHANISM:-
ABRASIVE JET MACHINING UTILIZES THE PRESSURE OF FLUID STREAM TO REMOVE MATERIAL FROM THE SURFACE OF THE JOB. WHEN USING AIR AS A MEDIUM THE MIXTURE OF AIR AND ABRASIVES ARE ALLOWED TO IMPINGE ON THE WORK SURFACE AT ABOUT 200 TO 400M/S THROUGH THE NOZZLE AND WORK MATERIAL IS ERODED BY THE HIGH VELOCITY ABRASIVE PARTICLES. THE INSIDE DIAMETERS OF THE NOZZLE ARE ABOUT 0.04MM AND STANDOFF DISTANCE IS KEPT ABOUT 0.7 TO1.0MM. THE PROCESS CAN BE EASILY CONTROLLED TO VARY THE METAL REMOVAL RATE WHICH DEPENDS ON FLOW RATE AND SIZE OF ABRASIVE PARTICLES .THE CUTTING ACTION IS COOLED BECAUSE THE CARRIER GAS SERVES AS A COOLANT.