This introduction paper is based on the paper "A REVIEW STUDY IN ENHANCING THE OPTIMISATION PROCESS FOR AA6351 ALLOY USING FSW TECHNIQUES - LITERATURE SURVEY" published by "MATERIAL SCIENCE AND TECHNOLOGY".
1. Overview:
- Title: A REVIEW STUDY IN ENHANCING THE OPTIMISATION PROCESS FOR AA6351 ALLOY USING FSW TECHNIQUES - LITERATURE SURVEY
- Author: T. Vijay Kumar, Dr. P. V. R. Ravindra Reddy, Dr. Arkanti Krishnaiah
- Year of publication: 2023
- Journal/academic society of publication: MATERIAL SCIENCE AND TECHNOLOGY
- Keywords: Solid type welding, Nonconsumable tool, Welding properties, FSW process analysis, Mechanical properties, Microstructural properties, Post weld heat treatment of the joints, Design of experiments, Corrosion of the joints
2. Abstract:
Friction stir welding is the solid type welding which uses best tool that is used to join two workpieces without melting the workpiece. Heat is produced by the friction between the workpiece and the tool. This heat only softens the metal but not melting it. The tool moves along the soften surface for joining purpose. The scope of welding is increasing day to day according to their needs. This paper reviews based on FSW process analysis, Mechanical properties, Microstructural properties, Post weld heat treatment of the joints, Design of experiments and Corrosion of the joints in Aluminium and its alloys.
3. Introduction:
Several advantages over fusion welding techniques have been attributed to friction stir welding's (FSW) use in joining materials that are difficult to weld with traditional methods, such as aluminium, magnesium, and copper alloys, as well as polymers. Notably, in FSW applications, flaws such solidification cracking, oxidation, distortion, and porosity -- all of which are frequent in traditional welding methods -- do not occur. Mechanical properties of friction stir welded joints may be influenced by a number of factors, including tool rotational speed, welding speed, axial force, tool pin shape, tool dipping, dwelling duration, etc.
4. Summary of the study:
Background of the research topic:
Solid-state welding, or SW, is a technique developed in 1991 by the TWI (Taiwan Welding Institute). This process is used to make a wide variety of structural additives, vehicle parts, ship components, and autos. Through this process, aluminium alloys such as AA5083, AA2024, AA7075, etc. were developed. Tool of pin shape, tool shoulder diameter, D/d ratio, rotational velocity, and welding speeds are all method parameters.
Status of previous research:
Ultimate tensile strength (UTS) and ultimate elongation (UE) of friction stir welded joints of identical and similar joints in AA6351 alloys were investigated utilising a variety of tool configurations. UTS and UE were shown to increase up to a certain ratio, then decrease above that ratio for joints of the same kind. Joint mechanical characteristics were analysed in respect to process factors, and correlations were established between the UTS, the UE, and the vertical force.
Purpose of the study:
The goal of this technique is to maximise a response surface whose values are dependent on a number of process factors. The response surface method consists of four main steps: (i) creating a design of experiments (DOE) to collect enough data about the process under study; (ii) developing a mathematical model based on a second-order polynomial surface that adequately fits the experimental results; (iii) determining which parameters can best optimise one or more responses; and (iv) analysing the relationships between the inputs and the outputs.
Core study:
The material investigated in the present work was AA6351 aluminum alloy, supplied in the form of 6 mm thick sheets. Blanks of AA6351 were cut to dimensions of 180 mm in length and 80 mm in breadth before being butted together using a friction stir welding procedure. During the course of the experimental campaign, a pin-shaped tool made of high carbon steel was used; this instrument had a shoulder diameter of 12 mm, a truncated cone pin with a base diameter of 3.5 mm, a height equal to 1.7 mm, and a pin angle of 30°.
5. Research Methodology
Research Design:
The suggested complete factorial design of experiments is summarised, which shows the design matrix including all 33 = 27 coded and uncoded conditions. Uncontrollable factors such as machine heating, ambient humidity, and temperature were taken into account by doing the experiments in a randomised sequence.
Data Collection and Analysis Methods:
Tensile tests were conducted at room temperature utilising the servo-hydraulic universal testing machine (MTS Systems Corporation, Eden Prairie, MN, USA) to measure two response variables, UTS and UE. Leica Microsystems (Berlin, Germany) Reichert-JungTM MeF-3s light optical microscopes were used to examine the microstructure of friction stir welded blanks.
Research Topics and Scope:
For uniting nonferrous metals and alloys, we developed a solid-state welding method called friction stir welding (FSW). Because it produces no waste and uses no resources, it offers numerous benefits over more conventional approaches. Multi-objective Taguchi-Grey-based optimisation of weld-quality-affecting process parameters for dissimilar aluminium FSW welds is shown here.
6. Key Results:
Key Results:
- UTS values increased with TP until a maximum value was attained. As TP got closer to the upper limit value used in this work (0.15 mm), the UTS went down
- Higher UTS was achieved when ω and TP were generally changed between 1800 and 2400 rpm and between 0.1 and 0.13 mm, respectively
- Higher UTS values were guaranteed by v values between 65 and 85 mm/min
- The UTS-related metamodel was shown to be more accurate, with a maximum deviation of 2.47%, compared to the UE-related metamodel's highest divergence of 11.34%
- Varying TP, ω, and v within the ranges of 0.1-0.13 mm, 1500-2500 rpm, and 150-220 mm/min, respectively, is optimal for increasing the tensile strength of AA6351-FSWed joints
Figure Name List:
- Figure 1 (microstructure of the base material)
- Various contour plots and surface plots showing parameter interactions
- Normal probability graphs for UTS and UE residuals
- Comparison between predicted and experimental values
7. Conclusion:
In this study, we change a number of parameters in order to get optimal results while using the friction stir welding technique on AA6351-T6 aluminium alloy. Two distinct second-order empirical formulations based on process variables including tool plunge, rotating speed, and welding speed allow for UTS and UE predictions to be produced. We improved the welded joint's UTS and UE by using a response surface method and three different metaheuristic methods to find the ideal FSW settings.
8. References:
- [List includes 75 references exactly as cited in the paper, from Altenkirch, J., et al. (2008) through Zadpoor, A. A., et al. (2009)]
9. Copyright:
- This material is a paper by "T. Vijay Kumar, Dr. P. V. R. Ravindra Reddy, Dr. Arkanti Krishnaiah". Based on "A REVIEW STUDY IN ENHANCING THE OPTIMISATION PROCESS FOR AA6351 ALLOY USING FSW TECHNIQUES - LITERATURE SURVEY".
- Source of the paper: DOI:10.10543/f0299.2023.41621 This material is summarized based on the above paper, and unauthorized use for commercial purposes is prohibited. Copyright © 2025 CASTMAN. All rights reserved.
Paper Summarize:
This comprehensive literature survey examines the optimization process for AA6351 alloy using friction stir welding (FSW) techniques. The research focuses on enhancing mechanical properties through process parameter optimization, utilizing response surface methodology and various experimental design approaches. The study demonstrates that optimal FSW parameters significantly improve ultimate tensile strength and elongation properties of AA6351 aluminum alloy joints.
Key questions and answers about the research:
Q1: What is the main advantage of friction stir welding over traditional fusion welding methods?
A1: FSW is a solid-state welding process that joins materials without melting them, using only the heat generated by friction to soften the material. This eliminates common defects like solidification cracking, oxidation, distortion, and porosity that frequently occur in traditional welding methods. Source: "A REVIEW STUDY IN ENHANCING THE OPTIMISATION PROCESS FOR AA6351 ALLOY USING FSW TECHNIQUES - LITERATURE SURVEY", Introduction section
Q2: What are the optimal process parameter ranges for achieving maximum tensile strength in AA6351-FSWed joints?
A2: The optimal parameter ranges are: tool plunging (TP) of 0.1-0.13 mm, rotational speed (ω) of 1500-2500 rpm, and welding speed (v) of 150-220 mm/min. Higher UTS was specifically achieved when ω and TP were changed between 1800 and 2400 rpm and between 0.1 and 0.13 mm, respectively. Source: "A REVIEW STUDY IN ENHANCING THE OPTIMISATION PROCESS FOR AA6351 ALLOY USING FSW TECHNIQUES - LITERATURE SURVEY", Key Results section
Q3: What experimental design methodology was used in this research?
A3: The research employed a complete factorial design of experiments with 33 = 27 coded and uncoded conditions, utilizing response surface methodology (RSM) to establish relationships between process parameters and response variables (UTS and UE). Source: "A REVIEW STUDY IN ENHANCING THE OPTIMISATION PROCESS FOR AA6351 ALLOY USING FSW TECHNIQUES - LITERATURE SURVEY", Research Methodology section
Q4: How accurate were the developed mathematical models for predicting joint properties?
A4: The UTS-related metamodel showed high accuracy with a maximum deviation of only 2.47%, while the UE-related metamodel had a higher divergence of 11.34%. Both models met the standards for modeling accuracy with minimal relative percent error and mean absolute errors. Source: "A REVIEW STUDY IN ENHANCING THE OPTIMISATION PROCESS FOR AA6351 ALLOY USING FSW TECHNIQUES - LITERATURE SURVEY", Validation of the Metamodels section
Q5: What tool specifications were used in the experimental campaign?
A5: A pin-shaped tool made of high carbon steel was used with the following specifications: shoulder diameter of 12 mm, truncated cone pin with base diameter of 3.5 mm, height of 1.7 mm, and pin angle of 30°. All welding procedures were carried out at a 2° tilt angle. Source: "A REVIEW STUDY IN ENHANCING THE OPTIMISATION PROCESS FOR AA6351 ALLOY USING FSW TECHNIQUES - LITERATURE SURVEY", Overview of the Experimental Campaign section
Q6: What are the key factors that influence the mechanical properties of friction stir welded joints?
A6: The mechanical properties are influenced by multiple factors including tool rotational speed, welding speed, axial force, tool pin shape, tool dipping, dwelling duration, tool plunging depth, and the heat input generated during the process. The interaction between these parameters determines the final joint quality and mechanical characteristics. Source: "A REVIEW STUDY IN ENHANCING THE OPTIMISATION PROCESS FOR AA6351 ALLOY USING FSW TECHNIQUES - LITERATURE SURVEY", Introduction and UTS and the Impact of FSW Parameters sections