Design & Development Of Automated Five Axis Cnc Ball End Magnetorheological Finishing Machine
Project Description :

In recent times the demand of products having surface finish of the order of nanometers has reached an all time high. this is due to these products having properties such as high corrosion resistance, high fatigue strength, high reflectivity and close tolerances in mating parts. the conventional finishing processes are incapable of generating nano finished surfaces due to limited control over finishing forces. this gave rise to the need for development of processes in which finishing forces could be precisely controlled. magnetic assisted advanced finishing processes such as mraff, mrf, mrh are magnetic fluid based processes capable of controlling the finishing forces by controlling the magnetic field externally. the fluid used in these processes for finishing purpose is known as magnetorheological polishing (mrp) fluid which is a composition of carbonyl iron particles (cip), polishing grade abrasive and a viscous carrying medium (oil or water). under normal conditions the abrasives and cip are randomly dispersed in the carrier medium, but under the application of magnetic field across the fluid the cip become tiny magnets and align themselves along magnetic field lines forming a chain like structure. these chains grip the abrasive particles firmly; the gripping of abrasives can be controlled by controlling the magnetic field externally. these gripped abrasives perform the finishing when this stiffened fluid is rubbed over the surface of a component. the above mentioned processes are most suitable to produce nano finishing on flat surfaces. however nano finishing requirements are not limited to flat surfaces only and are required on surfaces having 3d complex geometries such as concave, convex, freeform surfaces etc. to meet the industry demand for nano finishing of products with complex geometries iit delhi developed a mrp fluid based finishing process that resembles a ball end vertical milling cutter and is capable of finishing 3d surfaces. in this process an electromagnet is used to generate the magnetic field required to stiffen the mrp fluid which forms a ball ended shape at the tip of the tool. hence the process is named as ball end magnetorheological finishing process (bemrf). to meet rising demands for nano finishing of products having 3d complex surfaces, an industry ready 5 axis cnc bemrf machine tool is developed in this project. to cover freeform or three dimensional surfaces the machine is equipped with 5 axes motion, three linear motons in x, y (table movement in horizontal plane) and z (tool in vertical plane) directions and two rotary motions in b (tool rotation about y axis) and c (table rotation about z axis) directions. the bemrf machine contains (1) fluid delivery system (2) bemrf tool assembly (3) control panel (4) workpiece cleaning system and (5) confocal microscopy based roughness measurement system. the workpiece is first mounted on the work table; the fluid delivery system prepares the mrp fluid and then delivers it to the tool tip. once the mrp fluid is available on the tool tip the bemrf tool assembly generates the magnetic field which stiffens the mrp fluid and rotated along the vertical tool spindle. the linear and rotary motions are servo controlled in all motion axes, all servos are controlled by the drives in control panel. after completing the finishing cycle the workpiece is moved to the cleaning station where the residual mrp fluid is removed and the workpiece is made ready for measurement cycle. a confocal sensor scans the surface and gives roughness values to the controller which takes a decision whether further finishing is required or not. functions of all these sub assemblies are completely controlled by cnc part program.

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Project Details :
  • Date : Dec 20,2016
  • Innovator : Dilshad Ahmad Khan
  • Team Members : Zafar Alam,Faiz Iqbal,Dilshad Ahmad Khan
  • Guide Name : Dr. Sunil Jha
  • University : Indian Institutes of Technology Delhi
  • Submission Year : 2017
  • Category : Automation Engineering
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