Influence of tool pin profile on single sided friction stir welded joint (AA6061) E-Book

Dr. Chandan Deep Singh

• Herausgeber: BookRix
• Kategorie: Fachliteratur
• Sprache: Englisch

Veröffentlichungsjahr: 2018

Beschreibung

Friction welding is a solid state joining process used for joining of different metals that provides similar welding properties as like parent metal properties. In this welding process no filler metal is required and thus it’s a emissions less process. In this experiment for the purpose to joining of pieces include the generation of heat with the help of friction. Due to this pressure with variable speeds the tool moves on the work piece for joining of two metals. The soft layer of material will move out and angular movement starts during this process.

Leseprobe

Kanwaljeet Singh, Dr. Chandan Deep Singh

Influence of tool pin profile on single sided friction stir welded joint (AA6061)

BookRix GmbH & Co. KG81371 Munich

Chapter 1

INTRODUCTION

Friction Welding Overview

Friction welding is a solid state joining process used for joining of different metals that provides similar welding properties as like parent metal properties. In this welding process no filler metal is required and thus it’s a emissions less process. In this experiment for the purpose to joining of pieces include the generation of heat with the help of friction. Due to this pressure with variable speeds the tool moves on the work piece for joining of two metals. The soft layer of material will move out and angular movement starts during this process. The heat produce during this process is responsible for welding. More heat generated at initially the weld will strong more. So the welding is done by toll rotational speed and pressure applied and the traverse speed [33].

This technique is used for joining high strength aluminium alloys required less amount of heat input is required compared to conventional welding process like TIG and MIG. This solid state welding process leads to minimal micro-structural changes and imparts better mechanical properties than conventional welding. The process was basically conducted for aluminium alloys, but sin FSW was suitable method for welding of different materials. In simple welding number of defect produce the most common one is porosity in simple welding resulting due to entrapped gases that were not able to escape from the weld pool during solidification. The materials are being joined having lower temperature of tool as compared to melting point of the material at this temperature flow of the material start whish responsible for welding know as initial input heat. The friction stir welding having different gain over simple welding is less deformation and suited for the purpose of welding of aluminium alloys and produce better welding of pieces [12].

1.2 Types of Friction Welding

Friction welding is a practical method for welding of pieces that belongs to same category of material. For the purpose of welding two metals various types of welding method involved. In which friction welding is major welding having following different types which are

1.2.1 Rotary Friction Welding

Rotary friction welding is the main method utilized in friction welding and is to be used in many industries for the purpose of various kinds of work. In this process spinning the peace and bringing to close to each and holding component and with help for these two parts the heat generate that may lead welding process. [33].

1.2.2 Linear Friction welding

Two component are brought together one stable other one is unstable. The unstable part oscillates and unable to rotate. The welding times for parts are similar however it does not matter how big the part is. Because of the geometry, rotary friction welding does not have any type of friction in the middle of the rotating component. [33]

1.3 Friction Stir Welding

Friction Stir Welding (FSW) discover by TWI Ltd., UK in 1991. It was developed to weld high strength aluminum alloy. In aircraft and automotive part Al-Mg-Si (Cu) alloys mainly used. Rocket shells, hollow panels of wagons, and pipes are the common application of FSW. [18].

(FSW) having a simple principal. High carbon steel containing neglible consumability rotating tool with different pin profile feed between the two work piece and traversed along the line of joint and heat the work piece that may lead to flow the material to produce produces the joint [18].

Figure 1.1 Setup of Friction Stir Welding Process

Figure 1.2 FSW Weld zone & FSW Region

The production of heat in the fusion welding process and the succeeding microstructure of the material alteration are the cause for the disintegration of properties such that ductility, hardness and strength of welded parts. The extensive thermo mechanical deformations produce in conventional process which is produce less efficient joint but in case of FSW process joints having good properties tensile strength, ductility, hardness. [19].

Finally, the plastic deformation and forging action of the welding tool produces a weld metal with a finer grain structure than the base metal [34].

In aluminum alloys the FSW having generally improved properties than simple welding. Most of the work in friction stir welding has been done on aluminum alloys, where the mechanical properties were near those of the base plate. The advantages of FSW over conventional welding are following.

No filler materials are required.Less training is required and this is easily automated on simple milling machine.The FSW process can work in both horizontally and vertically.The quality of weld is good comparative to conventional process.The cross sectional welding field generated during welding.It create higher efficient weld joint in friction welding.The machine in the welding process play important role to complete the welding process.For the purpose to reduce defect such as inclusion of gas the Friction welding is used.Friction welding there is nothing to consumable therefore it becomes cost saving process.It has lower installation cost.In friction stir welding better mechanical properties of welding material achieved as compare to manual process.It prevent from the toxic fumes and the noise produce with molten material.

Some disadvantages of the process have been observed:

Exit spot remained with tool.To clamp the plates with each other great downward forced required.It simple welding there is large amount of flexibility involves but in case of FSW, it is very less flexible.In case of fusion welding techniques the traverse rate is faster as compared to the FSW process.

1.4 JOINTS PRODUCED BY FSW.

Friction stir welding produces following joints,

Full and partial penetration butt jointCorner jointLap jointDissimilar thickness butt jointTee jointLap fillet jointDouble sided butt joint

Fig. 1.3 Various FSW joints

1.5 WELDING DEFECTS

The following main defects occur in friction stir welds are

1.5.1 Flash- type defect