Metal Industry News, Welding Tips & Articles

Friction Stir Welding (FSW) is a welding process invented by TWI in 1991. The process involves a spinning tool, in contact with the material to be welded, with sufficient down force to create frictional heat in the material (about 80% of the material's melting point). This causes the material to become soft, allowing the spinning tool to create the weld.

FSW has significant advantages over other joining techniques including good mechanical properties, low distortion, and an ability to weld some materials that cannot be welded by other methods. Most current uses involve the joining of Aluminium alloys, for applications including:

• airframes
• aircraft components
• ship decking
• structures
• rail carriages
• automotive components
• bridge components
• pressure vessels
• space launch systems

In addition to Aluminium components, development of FSW has recently been reported for the joining of magnesium, copper, steels, and titanium alloys

Industrial take up of friction stir welding has been limited to those industry sectors that have sufficient capital to invest in the high technology costs. The need for purpose built ‘FSW’ machines can make it difficult for product manufacturers to justify implementation of the technology. An alternative approach is to adapt milling machines.

LOWSTIR Project

Unlike other friction stir welders, the LOWSTIR friction stir welding system includes a unit that attaches to most standard milling machines via an ISO taper, making it an affordable option for smaller enterprises. It is supplied with software to calibrate the system, monitor the welding process and log welding parameters for later analysis.

However, standard milling machines lack the process monitoring capabilities required to ensure high quality friction stir welded joints. LOSTIR (no ‘w’), the original project part funded by the European Commission in 2005 developed a low cost FSW monitoring system for retro fitting to milling machines to facilitate their application to FSW.

This process used a bespoke sensing head incorporating the tool holder, electronics, a ceramic heat shield and rotating antenna for transmission of the data to a stationery receiver, mounted onto the frame of the machine. The receiver is connected via cables to a signal processing module, computer and mains power supply.

Whilst this system has been used successfully for a number of years, the use of telemetry for the signal transmission means an antenna / receiver arrangement is necessary complete with cable connections. Additionally the electronics mounted within the sensing head are subject to severe vibration and heat.

Original system in action incorporating revolving antenna and static receiver

Bluetooth Data Transmission

To ensure the forces from the welding process do not affect the electronics and gain the benefit of a wireless system, the sensor head has been modified to use a battery power supply and a Bluetooth connection to transmit machining data to a stationery receiver I.E. a notebook computer fitted with a standard Bluetooth module. This modification means that the sensitive electronics and rotating antenna for the telemetry transmission is no longer required, nor are the stationery receiver or the signal processing unit, power supply or associated trailing cables.
The original design has been considerably revised to accommodate these changes, resulting in a reduction in the size of the sensor head, making it both lighter and stiffer.

The LOWSTIR system now comprises of just one hardware and one software component excluding the FSW tool, with the wireless link designed to support two way communications for calibration and data collection.

BAE’s Experience

Andy Wescott of BAE’s Advanced Technology Centre says one of the biggest problems with welding aluminium is distortion. However with the appropriate clamping in place and due to there being less heat generated by the process, this problem is largely overcome. A further benefit of using FSW is that high strength aluminium alloys can be welded, a process not possible using traditional techniques. Also recent trials have demonstrated FSW can be used to repair localised damage to large panels. Rather than replacing a large area with a single sheet of material at the existing weld or join, just the damaged area is repaired with a slug of new metal which is welded ‘in-situ’ leaving no step or change in the contour of the original material. This saves time and money compared to larger repairs requiring more specialised equipment or a return of equipment to workshops.

Another advantage of the stir welding technique is that no consumerables are used and as there is no arc drawn, there is no radiation, fume or spatter present. Additionally as it uses vastly less energy in the process, all told it is a very ‘green’ technique.

The ability to go wireless is a huge leap over the previous technology says Andy. Not having to worry about trailing cables to the laptop reduces set up time and makes measurements during welding very straightforward. The Bluetooth switch is a simple jack-plug arrangement, pull out the plug and the Lowstir device will search for the laptop. Once finished, simply replace the plug – that’s all there is to it. Also as the power supply is now built-in using a rechargeable battery, it makes it a very versatile system.
What was once a highly specialised measurement using equipment costing many hundreds of thousands of pounds, is now a relatively inexpensive process using equipment available in most engineering workshops, all driven by easy to use software.

Weld Monitoring System

A weld monitoring system has been developed to accurately measure the vertical and horizontal forces and torque on the tool. The sensor is machined from one piece of high grade stainless steel, heat treated for maximum strength and stability. The sensor design allows for various taper sizes to be attached to accommodate the requirements of the user. The data gathered can be directly linked to the acceptance or otherwise of the weld. In addition, the device has the capability to monitor two user defined temperatures via thermocouples, one to be attached to the FSW tool, the second will serve as a safety cut out to protect the integral telemetry circuit, monitoring the temperature at the interface between the tool holder and the weld monitoring system.


Control and Logging system

The information gathered by the LOWSTIR device is displayed to the operator using a notebook PC running NI Labview. The instrument panel displays real time numerical values of forces, torque, the temperature adjacent to the system electronics and (if desired) the tool temperature. The system also has the capability to add real-time event markers to allow correlation between process conditions/stages and the recorded data. The main display screen has buttons to start and stop recording of data. Alternatively an automatic trigger facility exists for initiating the recording of data.

The display also shows the current captured data values for the weld in progress and indicates whether they are within the acceptable range for satisfactory welding. The display also has a multi-graph facility where the user can select which sensor values are displayed.

Specifications:

Sigmapi Systems designs and builds automated control and monitoring systems. We have experience in several industry sectors – so, whatever problem you are looking to solve (maybe increasing production line speed, reducing scrap, testing new products, keeping items in controlled temperature environments or logging high speed events) we have engineers who can talk to you about the best solution.

Metal fabrication is a process of producing a metal component by modifying a raw piece of material in a machine shop. These materials are processed on different temperatures and depending on the range of temperatures; the process is classified as cold, warm and hot. Precision sheet metal fabrication describes various different processes that form sheet metal into finished products. Objects that are fabricated and used for machinery and other instruments are among the daily used objects like paper clips, computers, bolts, nails, automotive parts and many more.

There are various factors like rate of production, desired geometry, and other physical requirements that influence the fabrication process. The benefits of the metal fabrication process are far and wide because it is used by all industries. Every precision sheet metal fabrication process undergoes three primary processes that include forming, cutting and finishing. Forming is a process that alters the form of the flat metal sheet. Forming can be done using various different processes like annealing, bending, cold rolling, drawing, forging, mechanical working, press forming, roll forming and welding. After forming, a metal sheet is cut to alter the shape by removing some unwanted material. The cutting process includes stamping, shearing, sawing, drilling, blanking and punching.

Finally, the last stage is the finishing process. In this process, the shaped metal sheet is given a finished and soft surface using sanding and vibration techniques. Aesthetic considerations like painting and visual design applications are also few of the method applied to give the finishing touch. Some of the latest techniques in metal fabrication involve laser cutting, electro discharge machining, water jet cutting and wire cut EDM. In some cases CNC machining is also used.

There are various products that are created during precision sheet metal fabrication. The most common objects produced are metal cabinets, enclosures, ventilation shafts, hoods, exhaust systems, tanks and prototypes. Metal fabrication is also used by various other industries for food dispensing, food storage, communications, automotive, computer, medical, electronics, aerospace, telecommunication, pharmaceutical, residential and construction.

Some of the types of Precision Sheet Metal Fabrication include processes like Annealing (heating), Bending (straining), Cold forming, Cold rolling (shaping sheet metal using rollers), Drawing (material is forced into a die with a punch to form a cup-like shape), Forging hammering or pressing), Rolling (reducing thickness of the material), Extrusion (producing cylindrical bars or hollow tubes by forcing round billets through one or more dies) and Spinning (forms axially symmetrical shapes).

Metal fabrication equipment is used in important facets of the manufacturing industry. It serves the structural steel industry very well as it helps in other metal fabricating industries. Producers of this equipment have clients ranging from small and medium size enterprises to iron and fabricating shops and large construction companies.

The most common types of metal fabrication equipment include hydraulic press brakes, pinch rolls, plate shears, bending machines, tube benders and plate rolls. All these machines will help the entire workload easier. Look into the features of these types of equipment.

Hydraulic press brakes

Hydraulic press brakes are created to deliver the kind of ease and comfort an operator is looking for in the product. They are equipped with a ram system to provide maximum efficiency on operator control. Down stroking ram systems are favored over up stroking systems because they lessen operator fatigue. The system with a thick ram makes it easier to move in between extra heavy frames. Alongside with this component, a steel torsion is also utilized. At times, the hydraulic press brake contains limit switches and overload protection systems. Speeds of the press brakes are adjustable and controllable as well.

Hydraulic shears

This is yet another type of metal fabrication equipment used in order to make the job of individuals easier. Looking for those with foot pedals and emergency stops is highly favorable for the company. Programmable axes may help control blade gaps, stroke length, back gauge and shearing times. At times, the shears are also commendable for its capacity to transfer balls and load metal sheets. It also possesses a full protection guard system. Shears are used in order to provide smooth and quiet operation while cutting or manufacturing metal parts.

Plate bending machines

Plate bending machines vary according to specifications of the particular industry making use of this industrial product. There are goods that are best suited for small to medium production requirement for pipes, angles, flats and tubes. Ornamental and job shops will surely favor this type of bending machine. There are plate bending machines that are versatile enough with hydraulic forming features. This is commendable in industries were pipe, tube and aluminum extrusion bending is required.

There are other types of metal fabrication equipment sold by a lot of manufacturers. At times, this equipment may be available from second hand machine stores. What matters is that the machine will work for the particular manufacturing process it has to serve.

Visit the US-Asian Industrial Directory and Trade Portal to view offerings from Asian Manufacturers and exporters of industrial machines, equipment, tools and materials for industrial applications. Gain access to Asia's leading suppliers of metal fabrication equipment and other industrial products and services.

Forge welding is said to be the oldest welding technique ever used by early blacksmiths, dating back to the Iron Age when ancient Egyptians and people from Eastern Mediterranean began to refine the craft of welding iron metals together.

Also known as “fire welding,” this method attempts to fasten together two or more metal components through a process of heating, hammering and striking. It is also the “simplest” solid-phase bonding method that utilizes heat and pressure to create the weld.

Being able to join a host of similar and dissimilar materials, forge welding is very versatile. Although this technology has been around for centuries, it was not until the first half of the second millennium A.D when forge welding was formalized upon the publication of Vannoccio Biringuccio’s book entitled “De la pirotechnia” in 1540. This book contains descriptions of early forge welding techniques. However, due to the advent of industrialization which gave birth to more sophisticated welding methods, this technique has been replaced.

There are two ways of doing forge welding. One way is through solid-state diffusion which is applied to bond two similar metal components. This results in a weld that contains only the welded metals with no bridging materials or fillers. This application requires tedious surface preparation because too much oxidation of the faying surfaces would lessen the joint strength significantly. Another method of forge welding is by the formation of a lower melting temperature eutectic. This is being done between dissimilar materials, allowing you to make weld that is stronger than individual metals.

One of the most popular applications of forge welding is the manufacturing of pattern-welded blades. In this process, steels are repetitively drawn out, folded back and welded upon itself. Another lesser known application is the production of shotgun barrels. In this method, metal wire is coiled onto a mandrel before forging it into a barrel.

For a forge welding job to be successful, 50-90% of the melting temperature is recommended. Take note that steel welds at a much lower temperature than iron. Utmost care must be taken to prevent overheating the metals.

Learn setting up the welding machine from an expert in arc, tig and mig welding in this free DIY video.

Expert: Malcolm MacDonald
Bio: Malcolm MacDonald graduated from Connestoga College in 1968 from the Fitter Welding Program. He currently teaches a welding apprenticeship program.
Filmmaker: Melissa Schenk

PORT SAINT LUCIE, FL -- Tommy and Sabrina Creel, Father and Daughter at Custom Welding Diversified, Inc., recently launched a new product known as the Boat Storage Stand.

This revolutionary product will aide and revitalize marinas and boat storage facilities. It will help reduce the costs that are involved when storing boats.

The Boat Storage Stands are SELF leveling, light weight, and made from a high quality aluminum alloy. The aluminum material gives the stand a long life span, and the ability to survive the brutality of salt water. The patented stand uses two movable arms to self level the boat as it is lowered onto the stand. When the boat is removed the arms automatically rise into position immediately ready for the next boat.

The company is impressed with the demand for the stands and will continue production.
Please visit the company's website at http://www.Customweldingdiv.com for more information.

About Custom Welding Diversified, Inc.

Custom Welding was founded in 1992 by Sherri and Tommy Creel. It is a family owned and operated business located in Port Saint Lucie, FL. They specialize in welding, structural steel fabrication and erection, gas cylinders, and trailer and welding supplies. They perform both shop and portable (on site) assistance. Custom Welding's vision and mission is to provide speed, efficiency, accuracy and quality. The owners strive to aide their customers and greatly appreciate the business. The welding and fabrication background was key in the success of the idea and production of the Boat Storage Stand.

Contact: Sabrina Creel, Business Administrator
Custom Welding Diversified, Inc- 772.879.6928

As an authorized agent of the American Welding Society (AWS) since 2005, SGS, the world’s leading inspection, verification, testing and certification company offers Certified Welding Inspectors (CWI) seminars and examinations on behalf of AWS, and trains welding inspectors in five Latin American countries.

The training program prepares candidates for the AWS Certified Welding Inspector examination. Participants receive comprehensive welding inspection education and practical experience in welding processes and procedures. This training includes, among other topics, welding inspection technology and visual inspection workshops.

The AWS/CWI course schedule for 2009 is as follows: Columbia - Bogota, 20-25 April, 6-11 July, 30 November to 5 December; Peru - Lima, 16-21 March; Ecuador - Quito, 25-30 May; Panama - Panama City, 11-17 May; Venezuela - Caracas, 2-8 March, 13-19 July, 9-13 November.

The AWS/CWI Certification is recognized and accepted worldwide in the welding industry as it represents the quality of skills and knowledge in the field of welding.

SGS not only provides AWS Certified Welding Inspector Training and Examination but also provides Non-Destructive Testing (NDT) Training Courses and Certification Services as well as NDT Services. Non-Destructive Testing is a term used to describe the method of testing and inspecting materials or products for defects without damaging or destroying the items, for example with Time of Flight Diffraction (TOFD), which is a widely-used tool for flaw detection in welds, or with Dye-Penetrant Examination (PE) to detect welds.

The SGS Group is the global leader and innovator in inspection, verification, testing and certification services. Founded in 1878, SGS is recognized as the global benchmark in quality and integrity.