CHAPTER-1
INTRODUCTION
1.1 Introduction
These days, the focus of researchers is more on developing high-speed and environment-friendly technology in manufacturing techniques and this includes friction stir welding. Friction stir welding is a solid state joining process used for applications where the original melt characteristics must remain unchanged as far as possible. It was discovered in December 1991 and experimentally proven by Wayne Thomas and his team at welding institute in the UK. A rotating, non-consumable welding tool is used in FSW to soften the work material by producing heat due to friction and plastic work, thus permitting the tool to stir the joint surfaces. The weld is formed at temperatures below the melting temperature the workpiece. This technique has been used to weld a variety of similar and dissimilar alloys. The most effective part of FSW is the design of welding tool. Although many variations have been done recently to this basic tool shape to improve the quality and effectiveness.
1.2 Welding
Welding is an operation in which two or more parts or metals (similar or dis-similar) are united by means of pressure in such a way that there is continuity in the nature of the material (metal) between these parts. A filler metal, whose melting temperature is of the same order as that of the parent material, may or may not be used.
1.3 Classification of Welding:
Fig. 1.1 classification of welding processes
1.3.1 Friction Stir Welding
Friction stir
Welding is a process used to join metal parts by producing a coalescence, called a weld, at a joint. Advances in welding technology have opened the way for innovative designs in structures and machinery. Of modern welding processes, the greatest number fall under the general classifications of arc welding, gas welding and cutting, resistance welding, and brazing.
Since its development in the middle of the 20th century, MIG welding has become commonplace in many manufacturing operations. For example, it is commonly used in the automobile industry because of its ability to produce clean welds, and the fact that it welds metals quickly.
Welding dates back to ancient times! The early examples come from the bronze age when they used pressure welding to hold to gather small gold boxes. Pressure welding is used when two pieces of metal are heated up and pressed together and then rapidly cooled then the joints form together. This process is also known as forge welding and it was
Welding is the process of joining pieces of metal or other parts by heating the surfaces to the point of melting using a blow torch, electric arc, or other means. This careers demand has skyrocketed in recent years. According to Tri-County Technical College, welding is ranked as one of the top ten fastest growing career fields in South Carolina by the US Department of Labor (“Welding Associate's Degree”). Welding is a very meticulous career, to be a welder you have to be focused, careful and you have to have an extensive knowledge of the field to be successful. Welding requires a variety of skill sets. If a person has a variety of skills and experience doors will open up for positions such as: shipbuilding, automotive repair, and construction.
Gas metal arc welding, or most commonly referred to as MIG welding is a very common and sometimes preferred method of welding. Gas metal arc is personally one of the easiest and controllable welding types there is.
Welding must be done carefully to avoid contamination and machining must be done precisely. Titanium is very reactive to atmospheric gases and can result in degradation in the material. Titanium is weldable in annealing conditions but provide limited weld ductility and heat affected zone ductility. It can also be significantly strengthened by cold working.
The different gases produce a different weld because of the way the electricity flows through the arc contacting the base metal
I have also learned about the different types of welding, certifications you can earn, and what some career options there are for welders. There are several different types of welding some of them are Gas Metal Arc (MIG),Gas Tungsten Arc (TIG),Shielding Metal Arc (Stick), and Flux Cored welding.A few types of welding certifications are Certified Welding Engineer that is where they contract documents, buildings, or jurisdiction laws may require technical services to be performed under a certified engineer. There is Certified Robotic Arc Welding that is where it allows welding personnel in various sectors to measure themselves against standards for their occupation, and there is a Certified Welding Supervisor who
Pipeline welding is a job that consists of welders joining industrial sized pipes to each other in order for them to transport gasses, oil, and many other various substances across the country. The pieces of pipe are joined by electrically fusing molten metal to make the two pieces one. These pipes can stretch for thousands of miles and can be found all around the world. This job may overlooked in today’s time, but it is a very important feature that keeps this country running.
Pipe welding is a person with high professional skills that join pieces of metal to make one piece whole piece of metal. Welding is one of the most jobs that means that you join multiple sections of pipe and involves heating pieces of metal and joining them so that
Welding is evolving. It is adjusting, dynamic, and testing. It applies new information and logical standards, and it continually is growing its wildernesses.
If you want to be a welder, and actually have a career, you can go to a welding school and learn how to weld, or you can try to be a welders helper and just learn the trade. Welding can be a tough job if you don’t know what you are doing or you do not enjoy doing it. Welding is a fabrication or sculptural process that joins materials together (Modern Welding). This is the process that uses fuel gases and oxygen to make a molten pool of metal to fuse together two pieces of metal, called puddeling (oxy-fuel welding and cutting. Wikipedia). If you decide to weld as your profession, most welding school students have little trouble finding jobs and finding people certified to weld correctly (Welding.Wikipedia).
The history of welding has traveled from all around the world and has improved so much.Welding has believe to have started from 4000 B.C. and is still going on right now.
Welding is one way to join metals. In other words, welding is the process of joining metals by melting the parts and then using a filler to form a joint. It can be done
GMAW (Gas Metal Arc Welding) is more economic; Springer reports that “ GMAW is an economic process because it has higher speeds and higher deposition rates than manual arc welding. There is also no need to constantly change electrodes” ( Page 11). GMAW has a higher speed, which means that you can get the job done faster. It also has high deposition rates which makes the weld look clean and smooth.” This method can be used for a high range of work, but it is not suited for repair work because of it’s weld quality” (Page 4). This process can be used for many variations of work including root welds, joints, T’s, butts, laps, and many more applications. Even though its used for many practices, it is not recommended to use this method for