Abrasive Flow Machining

Abrasive Flow Machining

Mohit OstwalAssistant ProfessorDepartment of Mechanical EngineeringJodhpur Institute of Engineering and Technology, Co-ed, Jodhpur2/12/2016Mohit Ostwal, Asst. Prof., ME, JIET-Co-ed, Jodhpur1

ContentWhat is AFM?Need of AFMAbrasive MaterialMechanism of AFMClassificationOne WayTwo WayOrbitalProcess input parametersApplication areas

2/12/2016Mohit Ostwal, Asst. Prof., ME, JIET-Co-ed, Jodhpur2

Abrasive Flow MachiningIt is basically used as a deburring process.Developed in 1960 by Extrude Hone Cooperation.AFM canPolish and deburr parts internallyPolish through holesPolish intersecting holesCalibrate fuel injection nozzles to a specific flow ratesUses abrasive grains mixed in a putty (a form of cement) like matrix which abrades the surface/burrs from the specific area of the material.

2/12/2016Mohit Ostwal, Asst. Prof., ME, JIET-Co-ed, Jodhpur3

NEEDSmooth surfaces Aerospace and precision components

High flow rates Fluid dynamics and nozzles

Torque and fuel economy Fuel nozzles and engine components

Eliminate the imperfections Medical field2/12/2016Mohit Ostwal, Asst. Prof., ME, JIET-Co-ed, Jodhpur4

Abrasive MaterialAbrasivesAluminum oxideSilicon carbide Boron carbideDiamond Mixed in Polymeric mediumViscoelastic polymer- shows change in viscosity when under pressure2/12/2016Mohit Ostwal, Asst. Prof., ME, JIET-Co-ed, Jodhpur5

Mechanism Of AFM1. Initially the material is ploughed by the fine abrasives which come in contact with the work material as the rub over the metal surface with high pressure.2. The material flow occurs in the direction of the motion of abrasive particles as well as in lateral direction, resulting into the formation of the leaps.3. The further flow of abrasive particles causes continued work hardening which results in embattlement and fragmentation of the lips into micro chips. 2/12/2016Mohit Ostwal, Asst. Prof., ME, JIET-Co-ed, Jodhpur6

Mechanism of AFM

2/12/2016Mohit Ostwal, Asst. Prof., ME, JIET-Co-ed, Jodhpur7

Components of AFMMachineToolingWorkpieceFixture plateFixturesPumping deviceAbrasive materials/medium

2/12/2016Mohit Ostwal, Asst. Prof., ME, JIET-Co-ed, Jodhpur8

Classification of AFMOne wayTwo WayOrbital

2/12/2016Mohit Ostwal, Asst. Prof., ME, JIET-Co-ed, Jodhpur9

One-way AFMOne-way flow AFM processing pushes abrasive media through the work piece in only one direction, allowing the media to exit freely from the part.

2/12/2016Mohit Ostwal, Asst. Prof., ME, JIET-Co-ed, Jodhpur10

Advantages of One-way AFMFaster cycle processingEasy clean-upMedia temperature control generally not requiredAble to process larger partsSimpler tooling and part change-overAccurately replicates air or liquids natural flowDoes not encapsulate work-part in media2/12/2016Mohit Ostwal, Asst. Prof., ME, JIET-Co-ed, Jodhpur11

Two-way AFMMost widely used among the three.The typical two-way flow AFM process uses two vertically opposed cylinders to extrude an abrasive media back and forth through or around passages formed by the workpiece and tooling. Abrasive action occurs wherever the media enters and passes through the most restrictive passages

2/12/2016Mohit Ostwal, Asst. Prof., ME, JIET-Co-ed, Jodhpur12

Two-way AFM(contd.)

2/12/2016Mohit Ostwal, Asst. Prof., ME, JIET-Co-ed, Jodhpur13

Two-way AFM(contd.)

2/12/2016Mohit Ostwal, Asst. Prof., ME, JIET-Co-ed, Jodhpur14

Advantages of Two-way AFMExcellent process controlCan finish both ID and OD of componentGood control of radius generationFully automated system capabilitiesFaster setup & quick-change toolingFaster change-over of media2/12/2016Mohit Ostwal, Asst. Prof., ME, JIET-Co-ed, Jodhpur15

Orbital AFMSurface and edge finishing are achieved by rapid, low-amplitude, oscillations of the work piece relative to a self-forming elastic plastic abrasive polishing tool.The tool is a pad or layer of abrasive-laden elastic plastic medium (similar to that used in two way abrasive flow finishing), but typically higher in viscosity and more in elastic.2/12/2016Mohit Ostwal, Asst. Prof., ME, JIET-Co-ed, Jodhpur16

Orbital AFM(contd.)

Before starting of finishingAfter starting of finishing2/12/2016Mohit Ostwal, Asst. Prof., ME, JIET-Co-ed, Jodhpur17

AFM process parametersMachineAbrasiveWorkpieceExtrusion pressureFlow VolumeMedia flow speedNumber of CyclesMedium viscosityAbrasiveConcentrationAbrasivetype & sizeRestrictingpassage flowand areaDuctile/Brittle2/12/2016Mohit Ostwal, Asst. Prof., ME, JIET-Co-ed, Jodhpur18

AFM process parametersAbrasive BasedAbrasive grain size used in AFM varies from 500 grit (tiny hole) to 8 grit (stock removal and stocking)Large abrasives- cut fasterSmall abrasives better surface finish as well as they can reach narrow and complex surfaces easily.Machine BasedPressure - 0.7 Mpa to 22 Mpa (100 psi to 3200 psi) 2/12/2016Mohit Ostwal, Asst. Prof., ME, JIET-Co-ed, Jodhpur19

Capabilities of AFM processSurface finish in the range of 28 to 280 m.Hole of 0.2 mm can be made.Dimensional tolerances achievable upto 0.005mm.Can reduce surface roughness by 75 to 90% on cast, machined or EDM sufaces.

2/12/2016Mohit Ostwal, Asst. Prof., ME, JIET-Co-ed, Jodhpur20

ApplicationAerospace industryImproved surface qualityEnhanced cycle fatigue strengthOptimized combustion and hydraulicsIncreased airflowExtended component life

2/12/2016Mohit Ostwal, Asst. Prof., ME, JIET-Co-ed, Jodhpur21

Application2. Automotive industryEnhanced uniformity and surface quality of finished componentsIncreased engine performanceIncreased flow velocity and volumeImproved fuel economy and reduced emissionsExtended work piece life by reducing wear and stress surfaces

Grains in same direction will increase the flow rate2/12/2016Mohit Ostwal, Asst. Prof., ME, JIET-Co-ed, Jodhpur22

Application3. Dies and mold industryReduced production costsIncreased production throughputEnhanced surface uniformity, finish and cleanlinessImproved die performance and extend life of dies and molds

2/12/2016Mohit Ostwal, Asst. Prof., ME, JIET-Co-ed, Jodhpur23

Application4. Medical industry (Medical implants)Eliminate the surface imperfections where dangerous contaminates can reside Improved functionality, durability and reliability of medical componentsEnhanced uniformity and cleanliness of surfaces,Extended component life

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2/12/2016Mohit Ostwal, Asst. Prof., ME, JIET-Co-ed, Jodhpur25

THANK YOU2/12/2016Mohit Ostwal, Asst. Prof., ME, JIET-Co-ed, Jodhpur26