Surface Smoothing of A5083 Aluminum Alloy Plate by Friction Stir Forming

2019 ◽  
Vol 803 ◽  
pp. 50-54
Author(s):  
Takahiro Ohashi ◽  
Kento Okuda ◽  
Hamed Mofidi Tabatabaei ◽  
Tadashi Nishihara
Keyword(s):  
Aluminum Alloy ◽  
Feed Rate ◽  
Metal Plate ◽  
Spindle Speed ◽  
Back Surface ◽  
Alloy Plate ◽  
Friction Stir ◽  
Shoulder Diameter ◽  
Aluminum Alloy Plate ◽  
Aluminum Plates

This paper provides a framework for the transcription of the surface of a mirror-finished die onto a metal plate by friction stir forming (FSF). In FSF, a material is put on a die, then friction stirring was conducted on its back surface for the transcription of the profile of the die onto the material. In this paper, a mirror-polished die of JIS SUS304 stainless steel with surface roughness Sz 0.014 mm and a probe-less friction-stirring tool in 18 mm shoulder diameter were employed for the experiment. A5083P-O aluminum plates, 3 mm thick, were utilized as base metals for the transcription. The authors varied tool spindle speed and tool feed rate to evaluate the forming results. Consequently, a mirror-finished surface under the friction-stirring tool was successfully transferred from the die to the aluminum alloy plate. The roughness of the base metal before processing was Sz 0.022 mm and that of the processed metal was Sz 0.012–0.016 mm. Higher spindle speed and faster feed rate resulted in a smoother surface; it is thought that high spindle speed and faster feed rate should be effective for higher contact pressure between a die and a material.

Vertical Wall on an Aluminum Alloy Plate Fabricated by Friction Stir Forming

2017 ◽  
Vol 748 ◽  
pp. 202-206 ◽  
Author(s):  
Takahiro Ohashi ◽  
Hamed Mofidi Tabatabaei ◽  
Tadashi Nishihara
Keyword(s):  
Aluminum Alloy ◽  
Aspect Ratio ◽  
Vertical Wall ◽  
Thick Wall ◽  
Back Surface ◽  
Alloy Plate ◽  
Friction Stir ◽  
Key Factor ◽  
Aluminum Alloy Plate ◽  
The Relationship

This paper describes utilization of friction-stir forming (FSF) to generate a single wall on an aluminum alloy plate. The proposed process is as follows. The authors placed a material plate on a die having a variable-width groove and conducted friction stirring on its back surface. The material filled the cavity due to high pressure and heat caused by friction stirring. This process can be applied to generate thermal plate-fins and rib structures. The present study investigates the forming conditions and the corresponding results including the height limit of walls to obtain reference data for applications. In the experiment, a 3mm-thick JIS A5083P-O aluminum plate was utilized as the substrate. With a grove of less than 0.2mm-width, the wall was difficult to generate. The maxim height of the 0.2mm-thick wall formed by FSF was 2.8mm, and its aspect ratio was 14, which was difficult to form using conventional forging. Overall, the relationship between groove width of the die cavity and aspect ratio of maximum wall height to wall thickness followed the fractional curvature. This results implies that the deformable material volume generated by friction stirring is a key factor for wall height.

Fastenerless-Riveting Utilizing Friction Stir Forming for Dissimilar Materials Joining

2017 ◽  
Vol 751 ◽  
pp. 186-191 ◽  
Author(s):  
Takahiro Ohashi ◽  
Hamed Mofidi Tabatabaei ◽  
Tadashi Nishihara
Keyword(s):  
Aluminum Alloy ◽  
Steel Plate ◽  
Dissimilar Materials ◽  
Substrate Material ◽  
Back Surface ◽  
Forming Limit ◽  
Alloy Plate ◽  
Friction Stir ◽  
Aluminum Alloy Plate ◽  
The Individual

This paper proposes a new joining approach for dissimilar materials, called ‘the fastenerless-riveting,’ employing the friction stir forming (FSF). The FSF is a friction stir process invented by Nishihara in 2002. In FSF, a substrate material was put on a die firstly. Next, friction stirring was conducted on the back surface of the material. The material then deformed and precisely filled the cavity of the die due to high pressure and heat caused by the friction stirring. The authors utilized the FSF approach to generate rivet like joints as followings. First, a substrate which is capable for friction stirring, i.e. an aluminum alloy plate, was put on a dissimilar material plate having holes, i.e. a steel plate. The authors call the former ‘the host member,’ the latter ‘a joined member.’ These members were put on a die having the cavity to fabricate the head of the rivet-like structure. Then FSF was conducted to form the stems and heads of the structure. Joint members are able to be stacked within the forming limit. In the study, the authors firstly conducted the proof of the concept (PoC) tests to generate rivet-like structure between steel and aluminum alloy plate and between CFRP and aluminum alloy plate, then investigated the forming conditions, i.e. tool feed rate, tool pass and the corresponding results, including the volume of the generated stem and head of the individual rivet-like structure. 3mm-thick A5083P-O aluminum alloy plates was utilized as the host member, and a 0.7mm-thick SPCE steel plate and a 0.8mm-thick CFRP plate as the joined members.

Effect of Residual Aluminum Thickness on Microstructure and Strength of Friction Stir Spot Welded Aluminum Alloy/Copper Lap Joint

2021 ◽  
Vol 1042 ◽  
pp. 3-8
Author(s):  
Mitsuhiro Watanabe ◽  
Shinpei Sasako
Keyword(s):  
Aluminum Alloy ◽  
Pure Copper ◽  
Optical Microscope ◽  
Copper Plate ◽  
Laminate Structure ◽  
Alloy Plate ◽  
Friction Stir ◽  
Residual Aluminum ◽  
Welding Interface ◽  
Aluminum Alloy Plate

Dissimilar metal lap joining of A5052 aluminum alloy plate and C1100 pure copper plate was performed by using friction stir spot welding. The rotating welding tool, which was composed of a probe part and a shoulder part, was plunged from the aluminum alloy plate which was overlapped on the copper plate, and residual aluminum alloy thickness under the probe part of the welding tool after plunging of the welding tool was controlled in the range from 0 mm to 0.4 mm. The strength of the welding interface was evaluated by using tensile-shear test. Microstructure of the welding interface was examined by using an optical microscope and a field emission scanning electron microscope. The welding was achieved at the residual aluminum alloy thickness under the probe part of the welding tool below 0.3 mm. The welded area was formed at aluminum alloy/copper interface located under the probe part of the welding tool, and its width increased with decreasing the residual aluminum alloy thickness. A characteristic laminate structure was produced in the copper matrix near the welding interface. In the joint fabricated at the residual aluminum alloy thickness below 0.1 mm, hook of Cu was formed at edge of the welded area. The fracture did not occur at the welding interface. A remarkable improvement in strength was observed in the joint fabricated at the residual aluminum alloy thickness below 0.1 mm. The formation of laminate structure and hook is considered to result in joint strength improvement.

Friction Stir Forming of Aluminum Alloy Gear-Racks

2016 ◽  
Vol 725 ◽  
pp. 665-670 ◽  
Author(s):  
Takahiro Ohashi ◽  
Jia Zhao Chen ◽  
Tadashi Nishihara ◽  
Hamed Mofidi Tabatabaei
Keyword(s):  
High Pressure ◽  
Aluminum Alloy ◽  
Back Surface ◽  
Fill Ratio ◽  
Friction Stir ◽  
Single Pass ◽  
Shoulder Diameter ◽  
Gear Rack

Friction-stir-forming (FSF) of gear-racks of JIS A5083 aluminum alloy is reported in this paper. We put a material plate on a gear-rack die and conducted friction stirring on its back surface. The material deformed and precisely filled the fine cavity of the die due to high pressure and heat caused by friction stirring. This study investigates the forming conditions and the corresponding results, including the material fill ratio in the tooth. It is thought that the deformation volume of the material is key for the fill ratio, and the shoulder diameter of the tool in a single-pass process or the path area in a multi-pass process affects it as well.

Cylindrical Pin Embossment on A5083 Aluminum Alloy Substrate Fabricated by Friction Stir Forming

2017 ◽  
Vol 730 ◽  
pp. 253-258 ◽  
Author(s):  
Takahiro Ohashi ◽  
Hamed Mofidi Tabatabaei ◽  
Tadashi Nishihara
Keyword(s):  
Aluminum Alloy ◽  
Substrate Material ◽  
Back Surface ◽  
3D Measurement ◽  
Friction Stir ◽  
Single Pass ◽  
Tool Shoulder ◽  
Shoulder Diameter ◽  
Wide Range ◽  
3D Measurement System

This paper reports friction-stir forming (FSF) of cylindrical pin embossments on JIS A5083 aluminum alloy medium gauge plate. A substrate material was put on an emboss die and conducted friction stirring on its back surface. The die has 1mm diameter and 0.5mm deep fine holes at 1.5mm pitch on its top, and the material successfully filled them due to high pressure and heat caused by friction stirring. Three tools having different shoulder diameter were utilized to investigate the deformable area with a single pass. As a consequence, faster spindle speed, slower tool feed rate, and larger tool shoulder contribute to a wider range of completely formed pins. Extrusion of the material to the die cavity seemed to be mostly limited under the area of the shoulder. The ratios of the band width of the complete pins to the shoulder diameter were increased with the larger diameter of the shoulder of the FSF tool. Therefore, a larger shoulder was more effective for wide-range embossing with a single pass. In addition, we evaluated the shape of formed pins with a non-contact 3D measurement system. Accuracy of the height of the completely formed pins was within ±0.013mm, which was comparable with machining.

Study on Explosive Forming of a Light Alloy Plate

2006 ◽  
Author(s):  
Hirofumi Iyama ◽  
Shigeru Itoh
Keyword(s):  
Aluminum Alloy ◽  
Underwater Explosion ◽  
Metal Plate ◽  
Forming Limit ◽  
Experimental Conditions ◽  
Underwater Shock Wave ◽  
Alloy Plate ◽  
Metal Vessel ◽  
Aluminum Plates ◽  
Explosive Forming

The explosive forming is one of the forming methods of metal plates has been performed since 1950. This method is different from usual static press forming. The metal plate is accelerated by underwater shock wave, which is generated by underwater explosion of an explosive. We have tried the experiment of aluminum alloy forming using this method. In this research, a forming limit for aluminum alloy has been clarified from the experimental results. Then, we have tried the numerical simulation for this method using finite difference method. In this research, two methods for forming aluminum plates using closed metal vessel and paper vessel are introduced and the results of numerical simulations corresponding to those experimental conditions are shown.

Joint Formation and Mechanical Performance of Friction Self-Piercing Riveted Aluminum Alloy AA7075-T6 Joints

2019 ◽  
Author(s):  
YunWu Ma ◽  
YongBing Li ◽  
ZhongQin Lin
Keyword(s):  
Aluminum Alloy ◽  
Failure Mode ◽  
Feed Rate ◽  
High Speed ◽  
Shear Failure ◽  
Shear Fracture ◽  
Peak Load ◽  
Spindle Speed ◽  
Friction Stir ◽  
Lap Shear

Abstract AA7xxx series aluminum alloys have great potentials in mass saving of vehicle bodies due to pretty high specific strength. However, the use of these high strength materials poses significant challenges to traditional self-piercing riveting (SPR) process. To address this issue, friction self-piercing riveting (F-SPR) was applied to join aluminum alloy AA7075-T6 sheets. F-SPR is realized by feeding a high speed rotating steel rivet to aluminum alloy sheets to form a dissimilar material joint. The effects of spindle speed and rivet feed rate on F-SPR joint cross-section geometry evolution, riveting force and energy input were investigated systematically. It was found that the rivet shank deformation, especially the buckling of the shank tip before penetrating through the top sheet has significant influence on geometry and lap-shear failure mode of the final joint. A medium rivet feed rate combined with a high spindle speed was prone to produce a defect free joint with sound mechanical interlocking. F-SPR joints with the failure mode of rivet shear fracture was observed to have superior lap-shear peak load and energy absorption over the joints with mechanical interlock failure. The optimized F-SPR joint in this study exhibited 67.6% and 13.9% greater lap-shear peak load compared to, respectively, SPR and refill friction stir spot welding joints of the same sheets. This research provides a valuable reference for further understanding the F-SPR process.

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