This document provides an overview of abrasive flow machining (AFM). It discusses the need for AFM to machine advanced materials and its ability to achieve high surface finishes and tolerances. The mechanism of AFM involves extruding an abrasive media through workpieces to remove material. Process parameters like pressure, abrasive size, and flow volume affect the material removal rate and surface finish. AFM is used in industries like aerospace, automotive, and die/mold making to improve surfaces and extend component lifetimes. While effective, AFM also has disadvantages like high costs and an inability to process blind holes. Ongoing research is exploring hybrid processes and optimizations to address limitations.

1. Abrassive flow
machining
PRESENTED BY
Prabhakar kr singh(ME17M01)
Abhishek pal (ME17M14)

2. Content
1.Need of AFM
2.Introduction
3.Mechanism of material removal
4.components and accessories in AFM
5.Classification and their advantages Of AFM
a. One Way
b. Two Way
6.Process parameters and their effect
7.Capabilities of AFM
8.Application areas
9.Disadvantages and limitations
10.Scope and Optimizations
11.Reference

3. Need 0f AFM
 To cope up the rapid demand.
 To machine material like super alloys (inconel)
,ceramics, high performance alloys ,metal- matrix
-composits (c-fibre in Al matrix).
 Requirement of high super finish and high
tolerance .
 To have controlled temperature rise and residual
stresses.
 To machine the complex and intricate shapes .

4. INTRODUCTION
 Developed in 1960 by Extrude Hone Co-operation.
 AFM is a finishing process that removes small
quantity of material by flowing a semisolid ,
abrasive laden putty through and across a
workpiece . This abrasive media is extruded across
edge or surface to get desired .
 A hydraulic ram forces the abrasive medium
through the workpiece . As the abrasive medium
flows through the restriction , forces and velocity
increases sharply .

5. Mechanism of material
removal
 Penetration process
a. cutting = fracture(Brittle),
abrasion (Ductile)
b. deformation (plastic or ploughing)

6. Component of AFM
 Machine
 Tooling
1. workpiece
2. fixture (steel etc)
3. pumping device
 Abrasive material / medium

7. Accessories in AFM
 Pressure and Temperature
compensated flow control valve .
 Media heat exchanger
 Automatic flow timer

8. Classification of AFM
1. One-way AFM
2. Two-way AFM

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

10. Advantages of One-Way
AFM
 Easy clean-up
 Media temperature control
generally not required
 Able to produce larger parts
 Simple tooling and part change over

11. Two-Way AFM
The 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
work piece and tooling . Abrasive action occurs
wherever the media enters and passes through the
most restrictive passages

12. Advantages of Two-way AFM
 Faster cycling process
 Excellent process control
 Good control of radius generation
 Fully automated system capabilities
 Faster setup quick-change tooling
 Faster change over of media

13. AFM process parameters.
1. Machine
a. Extrusion Pressure (.69 to 22 MPa)
b. Number of Cycles (2 to several hundred)
2.Medium
a. Rheological properties of Media(viscosity
0.4to50Pas)
b. Type of Abrasive ( Al2O3, SiC,B4C, Diamond)
c. Abrasive grit size (8 to 500)
d. Concentration of abrasives and Carrier ( 70/30)
e. Type of Polymer Carrier ( poly-borosi-loxane)
f. additives
3.workpiece
a. Material
b. Hardness
c. Initial Surface Finish

14. Abrasive and Carrier
 Carrier
 Carrier = Rheopectic material = viscosity increases with
time .
 Carrier has enough degree of cohesion and tenacity to
drag the ABRASIVE with it .
 Abrasive
 Al2O3, SiC mostly used
 B4C , for very hard material
 Diamond for tungsten carbide

15. Parameters and their effect

17. parameter MRR SURFACE FINISH
GRAIN SIZE   
VISCOSITY   
PRESSURE   
VELOCITY   
FLOW VOLUME   
W/P HARDNESS   
ABRASIVE
CONCENTRATION

 

18. Capabilities of AFM
 Surface finish in the range of 0.1micron to
0.05micron
 Deburring, radiusing (rounding of sharp edges ),
and polishing are performed simultaneously in a
single operation
 Reduces surface roughness by 75 to90 % on cast
and machined surfaces
 AFM can process dozens of holes or multiple
passages parts simultaneously with uniform results
 Dimensional tolerances achievable upto ±
0.005mm

19. Application of AFM
 Automotive
 Aerospace
 Medicine
 Dies and Molds

20. AFM in Aerospace Industry
 Improved surface quality
 Enhanced high cycle fatigue strength
 Optimized combustion and hydraulics
 Increased airflow
 Extended component life

21. AFM in Automotive Industry
 Enhanced uniformity and surface quality
of finished components
 Increased engine performance
 Increased flow velocity and volume
 Improved fuel economy and reduced
emissions
 Extended work piece life by reducing
wear and stress surfaces

22. AFM in Dies and mold Industry
 Reduced production costs
 Enhanced surface uniformity, finish and cleanliness
 Improved die performance and extend life of dies
and molds

23. AFM in Medical Industry
 Eliminate the surface imperfections
where dangerous contaminates can
reside
 Improved functionality, durability and
reliability of medical components
 Enhanced uniformity and cleanliness of
surfaces
 Extended component life

24. Disadvantages and
Limitations
 Costlier
 High capital investment
 Processing of blind hole is difficult
 Fixtures are expensive
 It cant repair surface defect
 Large surface irregularities cant be removed

25. SCOPE AND OPTIMIZATION
 Centrifugal force assisted abrasive flow machining
has recently been tried.
 Magnetic Abrasive machining.
 Optimization using “TAGUCHI” technique
 New work on hybridization like ECM+AFM
(electrochemical-aided abrasive flow machining),
ultrasonic based AFM etc.

26. References
 M. Ravi Sankar, V. K. Jain*, J. Ramkumar, Abrasive flow
 machining (AFM): An Overview
  Rhoades L.J., KohutT.A., Nokovich N.P., Yanda D.W.,
 Unidirectional abrasive flow machining, US patent
 number 5,367,833, Nov 29th, 1994.
  Rhoades L.J., Abrasive flow machining, Manufacturing
 Engineering, (1988), pp.75-78.
  Williams R.E., Acoustic Emission Characteristics of
 Abrasive Flow Machining,Transaction of the ASME, 120,
 (1998), 264- 271.
 Gary F. Benedict
 Gov K, Eyercioglu O, Cakir MV. Hardness Effects on Abrasive Flow
Machining.
 Journal of Mechanical Engineering. 2013; 59: 626-31.
 Eyercioglu O, CAKIR MV, GOV K. Influence of machining parameters on
the
 surface integrity in small-hole electrical discharge machining. Proceedings
of the
 Institution of Mechanical Engineers, Part B: Journal of Engineering
Manufacture.
 2013.