Friction Stir Forming of Aluminum Alloy Gear-Racks with Semi-Closed Dies

2020 ◽  
Vol 977 ◽  
pp. 50-56
Author(s):  
Takahiro Ohashi ◽  
Hamed Mofidi Tabatabaei ◽  
Tetta Ikeya ◽  
Tadashi Nishihara
Keyword(s):  
Aluminum Alloy ◽  
Frictional Heat ◽  
Fill Ratio ◽  
Mechanical Joining ◽  
Friction Stir ◽  
Die Structure ◽  
Internal Forces ◽  
Net Shape Forming ◽  
The Difference ◽  
Gear Rack

This paper reports friction-stir forming (FSF) of gear-racks of JIS A5083 aluminum alloy with semi-closed dies. FSF is a modified friction-stir process suggested by Nishihara in 2002. The process generates frictional heat and internal forces, enabling massive deformation of the material. It has been successfully utilized for mechanical joining and microforming, but seems to offer an opportunity for net-shape forming of bulk products as well. We put a material in a semi-closed gear-rack die and conducted friction stirring on its top surface. The material deformed and filled the 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. We also investigated the difference between this method and open-type FSF that had been conducted with an open-die structure.

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.

Observation of Material Flow in Friction Stir Forming for A5083 Aluminum Alloy Gear-Rack

2017 ◽  
Vol 889 ◽  
pp. 113-118 ◽  
Author(s):  
Takahiro Ohashi ◽  
Hamed Mofidi Tabatabaei ◽  
Tadashi Nishihara
Keyword(s):  
Aluminum Alloy ◽  
Cross Section ◽  
Cross Sections ◽  
Material Flow ◽  
Transverse Direction ◽  
Back Surface ◽  
Friction Stir ◽  
Net Shape Forming ◽  
Material Forming ◽  
Gear Rack

This paper reports observation of material flow in friction-stir forming of aluminum alloy gear racks. Friction-stir forming was newly developed by Nishihara and is dedicated for material forming. In the process, a material plate is placed on the die and friction stirring is conducted on its back surface. The material deforms due to high pressure and heat caused by the friction-stir process and deforms precisely to the shape of the die. The process has mainly been studied for microforming and mechanical jointing; however it was successfully utilized for net-shape forming of A5083 aluminum alloy gear racks. The authors observed the appearance of products, change of mark-off lines on its surface, and deformation of its longitudinal cross section by photo-processing. In addition, we evaluated the distribution of hardness in transverse cross sections of a product tooth. As a result, it was observed that the material did not flow in the transverse direction of the cavity of the gear-rack die, though more material filled at the retreating side than at the advancing side. The material filled the tooth-cavity mostly before passage of the tool probe over the tooth.

scholarly journals Microstructure Evolution and Mechanical Property Characterization of 6063 Aluminum Alloy Tubes Processed with Friction Stir Back Extrusion

JOM ◽  
2019 ◽  
Vol 71 (12) ◽  
pp. 4436-4444
Author(s):  
Suhong Zhang ◽  
Alan Frederick ◽  
Yiyu Wang ◽  
Mike Eller ◽  
Paul McGinn ◽  
...  
Keyword(s):  
Aluminum Alloy ◽  
Microstructure Evolution ◽  
Electron Backscatter Diffraction ◽  
Deformation Gradient ◽  
Optical Microscope ◽  
Grain Structure ◽  
Frictional Heat ◽  
Friction Stir ◽  
Metal Extrusion ◽  
Backscatter Diffraction

Abstract Friction stir back extrusion (FSBE) is a technique for lightweight metal extrusion. The frictional heat and severe plastic deformation of the process generate an equiaxed refined grain structure because of dynamic recrystallization. Previous studies proved that the fabrication of tube and wire structures is feasible. In this work, hollow cylindrical billets of 6063-T6 aluminum alloy were used as starting material. A relatively low extrusion ratio allows for a temperature and deformation gradient through the tube wall thickness to elucidate the effect of heat and temperature on the microstructure evolution during FSBE. The force and temperature were recorded during the processes. The microstructures of the extruded tubes were characterized using an optical microscope, energy-dispersive x-ray spectroscopy, electron backscatter diffraction, and hardness testing. The process reduced the grain size from 58.2 μm to 20.6 μm at the inner wall. The microhardness of the alloy was reduced from 100 to 60–75 HV because of the process thermal cycle.

An Experimental Study of Process Parameters on Friction Stir Welded Aluminum Alloy 2219 Joint Properties

2017 ◽  
Vol 863 ◽  
pp. 3-7
Author(s):  
Koo Kil No ◽  
Joon Tae Yoo ◽  
Jong Hoon Yoon ◽  
Ho Sung Lee
Keyword(s):  
Aluminum Alloy ◽  
Friction Stir Welding ◽  
Solid State ◽  
Process Parameters ◽  
Process Condition ◽  
Welding Process ◽  
Frictional Heat ◽  
Friction Stir ◽  
Joint Properties ◽  
Aluminum Alloy 2219

Aluminum alloy 2219 is widely used in aerospace applications since it has a unique combination of good weldability and high specific strength. Furthermore, it can provide a high strength after heat treatment with superior properties in cryogenic environment so they have been widely used for cryogenic fuel tank of space launch vehicles. It is known that solid state welding like friction stir welding can improve the joint properties of this alloy. Friction stir welding is a solid state welding technology which two materials are welded together by the frictional heat due to the rotation of the tool. In this study, friction stir welding was performed on aluminum alloy 2219 sheets. The range of welding parameter is four rotation speeds from 350 to 800 rpm and six travel speeds from 120 to 420 mm/min. The results include the microstructural change after friction stir welding. The microstructure was characterized and material in the stirred zone experience sufficient deformation and heat input which cause the complete dynamic recrystallization. The present work represents the strength at each process condition and the optimum friction stir welding process parameters. The optimum weld efficiency obtained in this study was 76.5 %.

Friction-Stir Spot Mechanical Joining between Hot-Dip 55% Aluminum–Zinc Alloy-Coated Steel Sheet and A5083 Aluminum Alloy Plate Using Conventional Punching

2020 ◽  
Vol 853 ◽  
pp. 8-12
Author(s):  
Takahiro Ohashi ◽  
Taiki Ohno ◽  
Yuki Shiraishi ◽  
Hamed Mofidi Tabatabaei ◽  
Tadashi Nishihara
Keyword(s):  
Aluminum Alloy ◽  
Steel Sheet ◽  
Rear Surface ◽  
Zinc Alloy ◽  
Coated Steel ◽  
Alloy Plate ◽  
Mechanical Joining ◽  
Friction Stir ◽  
Coated Steel Sheet ◽  
Aluminum Alloy Plate

In this study, we fabricated a mechanical joining with spot friction-stirring between an aluminum alloy plate and an aluminum–zinc alloy-coated steel sheet; this was achieved by utilizing a conventional press-punching preprocess. In the preprocessing, a hot-dip 55% aluminum–zinc alloy-coated steel sheet was punched using a press and an inclined surface was generated at the wall of a punched hole due to shear droop. Subsequently, an A5083P-O aluminum alloy plate was positioned against it, and friction stirring was conducted on its rear surface. The hole was filled with the aluminum alloy to generate a mechanical interlock at the tilt of the wall. Further, we evaluated its cross tensile strength (CTS) and tensile shear strength (TSS) and obtained an average CTS and TSS of 368 kN and 1470 kN, respectively.

Effect of Rotating Tool Geometry on Mechanical Properties of Friction Stir Welded Aluminum Alloy 2195

2018 ◽  
Vol 783 ◽  
pp. 132-136
Author(s):  
Ho Sung Lee ◽  
Jong Hoon Yoon ◽  
Joon Tae Yoo
Keyword(s):  
Mechanical Properties ◽  
Aluminum Alloy ◽  
Fusion Welding ◽  
Frictional Heat ◽  
Tool Geometry ◽  
Welding Parameters ◽  
Space Vehicles ◽  
Friction Stir ◽  
Size And Shape ◽  
Welding Processes

It is known that Al-Li alloys show high specific strength and have been used in space vehicles with Friction stir welding (FSW). FSW has many advantages including the absence of porosity, low distortion and reduced residual stresses which are typical defects of the fusion welding processes. The process uses a rotating tool with a profiled pin that penetrates the parts to be welded. The tool starts to travel along the welding line and the softened material due to the frictional heat is stirred and mechanically mixed together by the rotating pin forming a weld in solid state without melting. Welding parameters such as tool rotational speed, travelling speed, and tool geometry are the main parameters which affect the material flow and the heat generation rate. The important tool geometry includes pin size and shape, pin tread and pitch, tool materials, and shoulder size and shape. The present work is to study the effect of tool geometry on the microstructure and mechanical properties of friction stir welded aluminum alloy 2195. Five different tool profiles have been used to investigate the effects of tool geometry on mechanical properties. The experimental results show that aluminum alloy 2195-T8 can be welded using FSW process with maximum welding efficiency of 75% using threaded cylindrical with concave shoulder at rotation speed, 600 RPM and welding speed, 300 mm/min.

scholarly journals Optimization of process parameters on friction stir welding of 2014 aluminum alloy plates

2017 ◽  
Vol 7 (1.1) ◽  
pp. 9 ◽  
Author(s):  
V. Jaiganesh ◽  
D. Srinivasan ◽  
P. Sevvel
Keyword(s):  
Aluminum Alloy ◽  
Friction Stir Welding ◽  
Aluminium Alloy ◽  
High Strength ◽  
Frictional Heat ◽  
Weld Strength ◽  
Electron Interaction ◽  
Welding Parameters ◽  
Work Piece ◽  
Friction Stir

Aluminum Alloy 2014 is a light weight high strength alloy used widely in the aerospace and also in other industries. 2014 is the second most popular of the 2000-series aluminium alloys, after 2024 aluminium alloy. However, it is difficult to weld, as it is subject to cracking. Joining of 2014 aluminium alloy in friction stir welding which is based on frictional heat generated through contact between a rotating tool and the work piece. Determination of the welding parameters such as spindle speed, transverse feed , tilt angle plays an important role in weld strength. The whole optimization process is carried out using Taguchi technique. The SEM analysis is done to check the micro structure of the material after welding by electron interaction with the atoms in the sample. Tensile test have been conducted and the s-n ratio curve is generated. The test is conducted and analysed on the basis of ASTM standards.

scholarly journals The Effects of Maintaining Temperature in Annealing Heat Treatment for an FSWed 6061-T6 Al Alloy

2013 ◽  
Vol 19 (S5) ◽  
pp. 69-72
Author(s):  
Seung-Jun Lee ◽  
Min-Su Han ◽  
Seong-Jong Kim
Keyword(s):  
Heat Treatment ◽  
Corrosion Resistance ◽  
Aluminum Alloy ◽  
Welding Process ◽  
Frictional Heat ◽  
Al Alloy ◽  
Friction Stir ◽  
Significant Difference ◽  
Annealing Heat Treatment ◽  
Annealing Heat

AbstractThe technological development of all kinds of lightweight transportation devices including vehicles, aircraft, ships, etc. has progressed markedly with the demand for energy saving and environmental protection. Aluminum alloy is in the spotlight as it is a suitable environmentally friendly material. However, deformation is a major problem during the welding process because aluminum alloy has a large thermal expansion coefficient. In addition, it is known that its corrosion resistance is excellent; nevertheless, in practice, considerable corrosion is generated and this is a major problem. To solve this problem, the friction stir welding (FSW) technology is applied extensively at various industrial fields as a new welding technique. This method involves a process in which materials are joined by frictional heat and physical force. Therefore, we evaluated improvements in mechanical properties and corrosion resistance through annealing heat treatment after FSW. The electrochemical experiment did not show a significant difference. However, the microstructure observation showed defectless, fine crystal particles, indicating excellent properties at 200–225°C.

A Study on Friction Stir Welding with Heating of Aluminum Alloy

2007 ◽  
Vol 353-358 ◽  
pp. 2041-2044
Author(s):  
Riichi Suzuki ◽  
Susumu Hioki ◽  
Naoki Yamamoto ◽  
Yuuta Kaneko ◽  
Takehiko Takahashi
Keyword(s):  
Aluminum Alloy ◽  
Friction Stir Welding ◽  
Welding Speed ◽  
High Speed ◽  
Room Temperature ◽  
High Efficiency ◽  
High Vacuum ◽  
Frictional Heat ◽  
Vacuum Vessel ◽  
Friction Stir

Conventional Friction Stir Welding (FSW) is that weld materials are joint at room temperature by stirring softened materials due to frictional heat of rotating tool. Therefore, high speed and high efficiency would be expected, as pre-heating make weld materials more softened, as well known that yield point goes lower due to heating. In this study, FSW was done to improve welding speed on FSW of aluminum alloy (A5052) for high vacuum vessel for processing of electronics devices. As the result, welding speed was 2.0 times to more than 3.0 at 300 oC comparing with conventional FSW at room temperature, using improved a milling machine with heater.

Grain Refinement of Mg-Y-Zn Alloy by Friction Stir Processing

2007 ◽  
Vol 26-28 ◽  
pp. 465-468 ◽  
Author(s):  
Taiki Morishige ◽  
Masato Tsujikawa ◽  
Sachio Oki ◽  
M. Kamita ◽  
Sung Wook Chung ◽  
...  
Keyword(s):  
Grain Size ◽  
Magnesium Alloy ◽  
Grain Refinement ◽  
Friction Stir Processing ◽  
Az31 Alloy ◽  
Frictional Heat ◽  
Light Metals ◽  
Friction Stir ◽  
The Difference ◽  
Zn Alloy

Grain refinement of magnesium alloy by Friction Stir Processing (FSP) was investigated. It is assumed that dynamic recrystallization (DRX) is occurred by frictional heat and plastic flow during FSP. This process is the effective method of the grain refinement for light metals. In this study, FSP was conducted to cast Mg alloys for and the difference of the grain refinement by DRX in these alloys was examined. As a result, in comparison with commercial Mg-Al-Zn alloy and Mg-Y-Zn alloy have finer microstructure. The grain size of FSP-ed Mg-Y-Zn alloy was ~1.7 [/m], however, that of AZ31 alloy was 20~30 [/m].

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