Friction stir welding presentation of Aluminium

FSW PPT by Researchers on Al-6061

1. Hardness Variations on longitudinal and transverse sections of Al 2024 specimen processed by Friction Stir Processing Mehar Chowdhry Department of Mechanical Engineering, Dayalbagh Educational Institute, Agra National Conference on Mechanical Engineering – Ideas, Innovations & Initiatives, AMU Aligarh

2. Friction Stir Processing- Introduction

3. Concept of FSP

4. Material Used The material used for friction stir processing is Al 2024. Specimens were made in the form of rectangular plates of thickness 6mm for the purpose of experimentation. Aluminum and its alloys are used extensively in aerospace and automotive industries because of their low density and high strength to weight ratio. The most widely used heat treatable alloy for aircraft and aerospace is Al2024. It has good formability in the annealed temper condition. It has excellent fatigue properties when compared to other aluminum alloys, excellent strength to weight ratio and good machinability. Friction stir processing was then done on Al 2024 specimens by maintaining a constant feed rate and varying the rpm.

5. Tool Specifications Cylindrical Pin tool Tool Material Alloyed Heat Treated Steel Tool Geometry Cylindrical pin tool Length of the tool pin 4.5mm Feed rate of tool 15mm/min Rotational speed 1200 rpm, 1800 rpm Plate Thickness 6mm

6. Experimental Setup The experimental setup consisted of a modified horizontal milling machine. A special fixture was also made to clamp the plate. Work piece clamped by the use of three nuts and bolts welded on the fixture. Helped to prevent the bulging in specimen.

7. Processed Specimen The processed specimen consists of the nugget zone, the advancing side and the retreating side. After conducting FSP on the Al 2024 plate, the specimen was prepared for the hardness tests by filing the top surface where FSP was conducted. Later, it was subjected to hardness tests to compare the hardness various with the unprocessed specimen.

8. Hardness Tests Various tests were conducted to find the hardness of the processed specimen and compare with that of the unprocessed specimen. The variation of hardness across various sections considered on the specimen is shown through various graphs plotted. The figure below is an indicative of how the specimen is divided into various sections across the entire span of the work piece in the longitudinal as well as transverse directions.

9. Hardness Variation at 1200 rpm and 1800 rpm and comparison with the unprocessed specimen On the basis of the hardness results of the processed and unprocessed specimen, various graphs have been plotted comparing the variation of hardness across various longitudinal and transverse sections at two different rpm considered i.e , 1200 rpm and 1800 rpm

10. Section A-A’ SPECIMEN MAXIMUM HARDNESS (HB) Unprocessed 65 Processed (1200 rpm) 134 Processed (1800 rpm) 81

11. Section B-B’ SPECIMEN MAXIMUM HARDNESS (HB) Unprocessed 65 Processed (1200 rpm) 155 Processed (1800 rpm) 96

12. Section C-C’ SPECIMEN MAXIMUM HARDNESS (HB) Unprocessed 65 Processed (1200 rpm) 139 Processed (1800 rpm) 80

13. Section D-D’ SPECIMEN MAXIMUM HARDNESS (HB) Unprocessed 65 Processed (1200 rpm) 155 Processed (1800 rpm) 76

14. Section E-E’ SPECIMEN MAXIMUM HARDNESS (HB) Unprocessed 65 Processed (1200 rpm) 155 Processed (1800 rpm) 76

15. Section F-F’ SPECIMEN MAXIMUM HARDNESS (HB) Unprocessed 65 Processed (1200 rpm) 133 Processed (1800 rpm) 85

16. Section G-G’ SPECIMEN MAXIMUM HARDNESS (HB) Unprocessed 65 Processed (1200 rpm) 133 Processed (1800 rpm) 84

17. Conclusions The hardness value increases from average value of 60 Hb to 150 Hb , thereby exhibiting an increase of 150% after Friction Stir Processing and this increment in the hardness will be responsible for the superior mechanical characteristics . An increase in the hardness values is an indicative of the increase in the strength characteristics of the specimen. The hardness value increases by 50% when the tool is rotated at 1800 rpm and by 150%, when it is rotated at 1200 rpm. The hardness values reach a maximum at the point at which the tool is introduced to the work piece. The maximum hardness was achieved in the Nugget Zone (~155 Hb ) at the lower rotational speed of the tool at 1200 rpm.

18. THANK YOU

19. References Charit I, Mishra RS., 2003, High strain rate superplasticity in a commercial 2024 Al alloy via friction stir processing. Mater Eng A; 359:290–6. Itharaju , Rajeswari R., 2004, Friction Stir Processing Of Aluminum Alloys, University of Kentucky Master's Theses. Paper 322 Nadammal ,  Naresh , Kailas, Satish , Suwas, Satyam, A bottom-up approach for optimization of friction stir processing parameters; a study on aluminium 2024-T3 alloy , Volume 65 Zahmatkesh B. , 2010, Enayati M.H., Karimzadeh F. Tribological and microstructural evaluation of friction stir processed Al2024 alloy, Materials and Design 31 4891-4896 Karthikeyan L and Senthil Kumar V.S., 2011 Relationship between Process Parameters and Mechanical Properties of Friction Stir Processed M6063-T6 Aluminum Alloy, Materials and Design, Vol . 32, pp. 3085-3091 Mosallaee M and Dehghan M, 2014, Improvement of Structural and Mechanical Properties of Al-1100 Alloy via Friction Stir Processing, JMEPEG 23:3786-3793 Elangovan K., Balasubramanian V., 2008, Influences of tool pin profile and tool shoulder diameter on the formation of friction stir processing zone in AA6061 aluminium alloy, Materials and Design 29 362-373