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Charlotte Allen: Reflecting On My Apprenticeship So Much

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1st calendar year Apprentice at Alpha Production Charlotte Allen has thrown herself into her Apprenticeship from day a single, and subsequent on from her past blog site, Charlotte updates up on what is she’s been up to these previous couple of months:

“So, the place to start out? I am now 8 months into my apprenticeship with Alpha Production and a good deal has improved due to the fact I 1st wrote about what it is like to be an Apprentice. Through these previous 8 months I have attended a amount of situations this sort of as Careers Fairs with our Apprentice Manager William Davies-Hill to explore with Calendar year 11 and 10s all about the astounding possibilities that can appear from going into an apprenticeship following leaving university. It is so inspiring to converse to the youthful folks, especially ladies who are in the similar posture I was in only a calendar year or so in the past, and find out about their thoughts on engineering and persuade these girls to consider the leap and join myself and so quite a few other folks in the industry.

“I have also ventured onto the factory flooring for the 1st time given that starting up the apprenticeship and – wow – there was so considerably to find out! From investing a week with some of the 2nd-12 months apprentices generating crawling boards for our sister organization Bri-Stor Units, to mastering all about how to match applications into the CNC Punch equipment. I have also had the privilege of doing work inside the model-new Chemical Technologies manufacturing facility below the supervision of the manager Justin Kelly, acquiring an perception to all the ground-breaking do the job that is heading to be having spot in the factory and supporting set up generation ready for June.

“During the Easter Holiday seasons, us initial 12 months apprentices took the yearly trip to Elan Valley. It was a superb week entire of workforce developing exercises to actually get us performing superior as a group. We climbed our reasonable share of Dames, tried to construct a raft to get throughout the river and heaps of orienteering things to do. On our final day we assisted the neighborhood nursery spruce up their outside the house backyard space. It was this sort of a enjoyment to give again to the wonderful group and give the young children a new and enhanced house to commit their time.

“On a private take note, I finished the 7 days off extremely delighted as I ultimately passed my driving check- so no much more early mornings and mentor outings to the JCB Academy for me. Hooray!

“Meanwhile at the JCB Academy, I have started off my welding class – I certainly consider a learn course with Alpha’s incredibly possess pro welder Chloe Sales is wanted! It is good to be in a position to glimpse back from wherever I started out and truly see the development, I’ve designed from staying terrified to make problems to mastering from them every single one working day with the assist from our tutors. I have cherished every next of the courses so far and I am certain it will only grow for the months remaining to arrive.”

MIG Welding Explained | Fractory

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MIG welding is an arc welding process that joins two metals together using a consumable wire electrode. As the wire strikes the welding arc, the welding area is protected by a shielding gas to prevent weld contamination. This process started gaining global popularity between the late 1940s and early 1950s as a tool for welding aluminum and other common metals.

Fast forward a few decades and MIG welding has become one of the most attractive welding techniques thanks to its unrivaled speed while offering consistency and quality at the same time. Given its simple and straightforward process, MIG welding is a great starting point for welders who can then later transition to other more complex welding techniques.

What Is MIG Welding?

Metal inert gas (MIG) welding is a subtype of gas metal arc welding (GMAW). In this welding process, the base materials are joined together through a welding current. Filler metal is constantly fed through the welding gun. As the electric arc melts the electrode wire it is then fused along with the base metals in the weld pool. Simultaneously, the shielding gas travels along the welding gun to keep the weld free from atmospheric contamination.

Although MIG and TIG welding are quite similar in several aspects, they have some key differences. MIG uses a consumable wire electrode which is fused with the base metals in the weld pool, whereas TIG uses a non-consumable tungsten electrode and the use of filler metal is optional and is added to the weld pool separately.

As the wire welding process has diversified and improved over time, different shielding gases have been taken into consideration for various types of metals and welding procedures. Metal active gas welding (MAG) has become another option alongside MIG, as it creates an avenue for different weld results and materials such as carbon steel.

Difference Between MIG and MAG Welding

Both metal inert gas (MIG) and metal active gas (MAG) are fusion welding processes and belong to the GMAW family. They’re often seen as one welding technique because apart from the shielding gas, the welding process is exactly the same. Both of these processes are performed using the same welding machine.

  • MIG welding uses inert shielding gases (argon, helium, nitrogen, or a mixture of the three). These inert gases are stable during welding, wherein it does not diffuse particles to the weld bead. MIG is generally used for welding aluminum, magnesium, copper, titanium, and other non-ferrous metals and alloys.

  • MAG welding uses active shielding gases or a mixture of active and inert gases (CO2, Ar + 2 to 5% O2, Ar + 5 to 25% CO2 and Ar + CO2 + O2). The two common active gases in MAG welding are oxygen and carbon dioxide. Due to the extreme temperature during welding, these active gases disintegrate and alter the chemical composition of the weld bead. This type of welding is generally preferred for carbon steel (especially mild steel) and stainless steel.

Between the two, MAG welding is desired if you need to alter the chemical and mechanical properties of the weld.

MIG Welding Process

First off, all the metals must be clean to weld. Rust and impurities should be removed using a metal brush. As with any other welding project, it is important to always wear appropriate safety gear. Now let’s proceed to the welding process itself.

How MIG Welding Works

MIG welding uses a constant voltage power supply to create an electric arc that fuses the parent material with the wire that is continuously fed through the welding torch. At the same time, an inert gas is extracted from a supply tank and flows towards the gun, allowing the shielding gas to evenly protect the weld pool from impurities.

There are a few things that need familiarising before using a MIG welding machine. Here are some details you’d certainly want to check out.

Metal transfer mode

MIG welding has some distinct modes for transferring the metal wire to the weld pool. These variations allow you to have quality welds depending on the application, type of metal or finish.

GMAW Modes of Transfer

GMAW Modes of Transfer

  • Short-circuit welding (aka dip transfer or microwire) – Electrical short-circuits are established as the metal wire touches the weld pool. To achieve this, MIG welding machines are operated with low voltage, keeping the size of the weld ball fairly small. The limitation in using short-circuit welding is its inability to weld thick materials.

  • Globular transfer – The welding current and voltages are raised above the recommended maximum values, creating an uncontrolled short circuit. Molten metal droops into the weld pool and typically has a higher diameter than the wire feed itself. This aggressive method causes erratic movement to the weld which in turn generates spatter. Its use is limited to flat and horizontal welds and lack of fusion in the weld is quite common. Globular transfer mainly finds use when welding thicker materials since large droplets and high heat input allow for good penetration. However, high temperatures lead to changes in the metal’s microstructure and to the formation of heat affected zone (HAZ).

  • Spray welding – Increasing the welding current and voltage further will cause a high deposition rate for the metal, almost similar to a water hose. This technique is optimal for joining thicker materials, allowing for greater penetration with tiny little droplets of molten metal. Spray welding offers strong, aesthetically good-looking welds with little spatter as no short circuits are occurring. High heat input restricts the use of this mode on thinner materials.

  • Pulsed mode – This mode is generally used for welding stainless steel and aluminum. It combines the advantages of other forms of transfer while minimising their disadvantages. The material is transferred in a controlled droplet form. The pulses create spatter-free welds and a lower heat input allows using this method on thinner materials.

Wire electrode

There are several types of wire electrodes available to tackle different projects and metals. As these electrodes run through the same wire feed unit, they behave differently during the welding process and leave distinguishable results.

  1. Hard wire is the general wire used by most MIG users as it is affordable and easy to control. This wire usually comes in large reels and can be used at different angles. Typical hardwires used are in a combination of 72/25 argon and Co2 ratio.

  2. Flux core wire requires no shielding gas for the welding project as the flux is built into the wire itself. Portability is a great bonus with flux-cored wires as there is no need to carry a gas tank around. The absence of an additional shielding gas makes flux-core more suited to working outdoors and in windy conditions. This is extremely convenient and user-friendly but on the downside, these wires create slag during welding. Investing in a good metal brush will come in handy for the cleaning procedure.

Inert gas

As the metals fuse in the welding zone, MIG welding gas is supplied through the welding torch to keep the weld pool free from contamination. These inactive gases have no effect or reaction to the weld, keeping the metal’s properties intact.

The most commonly used gases in MIG welding are argon and helium. Sometimes they’re mixed with other gases as these two noble gases are quite expensive.

Additionally, semi-inert gases can be used that contain small percentages of carbon dioxide (CO2). Cheaper than argon and helium, CO2 allows for deeper penetration while resulting in more spatter in the weld pool. This means that more cleanup is required to clean the welds after gas metal arc welding.

In specific situations, non-inert gases are used in very small percentages to further increase metal penetration. The downside is that oxygen creates rust and oxidation to the weld metal, which can affect the weld quality.

Welding torch

A welding torch or gun is a specialised tool for fusing and melting metals. MIG torches offer versatility in their application for a variety of metal thicknesses and types of metal. Similar to TIG, MIG torches are divided into two groups:

  • Gas-cooled welding torches are normally enough for the common welder doing minor projects. With larger projects overheating might become an issue.

  • Water-cooled welding torches can be used at higher amperages and provide more power. They also offer smoother control over the contact tip of the nozzle. However, they cost 20-30% more than gas-cooled torches and require the welding machine to have a water-cooled system installed in the unit.

Aside from choosing the welding torch, it is important to have the correct components installed for the project at hand. One of these components is the liners in the welding gun. Liners are guides that ensure the smooth feeding of the wire during welding. Their use is rather straightforward, as they need to match the type of metal along with the wire diameter of the spool.

Take note that there are four different nozzle types used in a welding torch: recessed, flush, protruding, and adjustable. The simplest way to decide which nozzle to use is to identify the type of wire electrode used in the project.

Power source

semi-automatic mig mag welding machine

The power source in a MIG welder is mostly set into DC as it offers constant voltage in contrast to TIG and stick welding which use alternating current for some materials. Modern MIG welding equipment auto-corrects the current when the arc length and wire feed speed change, allowing the MIG welder to create a stable weld puddle.

  • DC positive polarity – In DCEP (direct current electrode positive) or reverse polarity, the electrons flow from the contact tip of the electrode to the base metal. This is the most widely used setting since it offers a stable arc, ensuring better bead quality, weld penetration, and less spatter. Suitable for welding both thick and thin materials.
  • DC negative polarity – In DCEN (direct current electrode negative) or straight polarity, the electrons travel from the base metal to the tip of the electrode wire. This method offers faster deposition rates than DCEP but it has several drawbacks such as lack of penetration and not enough heat in the weld pool. Not suitable for thicker materials but is sometimes used for welding thin metals.
  • AC power – AC is hardly ever used in metal inert gas welding. It is used for welding non-ferrous metals while operating under a tight budget. Other welding methods are preferred instead of using AC power, as the trouble of losing arc control and spatter in the weld pool are bad as it is.

Advantages of MIG Welding

  1. The continuously fed wire allows for a fast, uninterrupted welding procedure.

  2. A MIG torch handles horizontal, vertical or flat welding positions with ease.

  3. MIG welding is cleaner than most welding processes, leaving little slag and minimal spatter compared to stick welding. The quality and looks offered by tungsten inert gas (TIG) welding are still unmatched though.

  4. MIG welding is one of the simplest welding techniques to learn.

  5. Suitable for a wide range of metals and alloys.

  6. The machine allows you to adjust a variety of weld settings, such as wire speed and amperage.

Disadvantages of MIG Welding

  1. There are other welding processes that offer more control to the weld (e.g. TIG).

  2. MIG welding equipment has a relatively high initial cost.

  3. MIG is generally unsuitable for outdoor welding with flux-cored arc welding being the exception here.

  4. Portability is an issue as MIG welders are heavy, considering the roll of wire and the tank containing the shielding gas.

  5. Spatter can form in the nozzle from the molten residue as the welding wire is fed into the torch.

Important Points to Remember

MIG welding is a cost-efficient and diverse welding process, making it one of the most attractive welding methods, especially in industrial environments. It is used extensively in the sheet metal industry but is quite commonly used for thicker workpieces as well.

MIG process can be automated by using welding robots and thus it is probably the most common welding method used in serial production. In the automotive industry, the process is often used as a substitute for resistance welding. As companies want to increase production capacity whilst keeping reasonable quality and efficiency, it makes sense that they most often resort to MIG/MAG welding.

With the continuous research and development into different combinations of shielding gases, polarities, etc, it is clear that the importance of MIG/MAG welding won’t be diminishing and these processes will continue to define the manufacturing industry for decades to come.

What is Tungsten Utilized For?

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Tungsten is a rare, obviously developing metal with the chemical image W – as it is also regarded as Wolfram. This versatile material has a variety of makes use of across many industries. So what are tungsten’s attributes, and how is it typically utilized?

In this post, Exclusive Metals – expert fabricators and suppliers of major good quality refractory metals for all programs – present a run-down of the features of tungsten metal and describe how it is most normally utilized.

Why Tungsten? Houses and Works by using

As a materials, tungsten is highly flexible and tough. It has a melting point of 3422°C – the best of any pure metal.

For this purpose, it is consistently employed in environments the place really large temperatures are typical. It is made use of to manufacture goods this sort of as jet engine components, gentle bulb filaments and crucibles.

It can also be made use of as aspect of an alloy in purchase to make other metals much more resistant to heat – in addition, it offers an incredibly very low amount of thermal expansion, meaning it is less probable to warp or swell when scorching.

It has a tensile power of 1510 megapascals, too – the greatest of all pure metals – and this, along with its minimal thermal growth, will make it ideal for the fabrication of superior-speed instruments.

Tungsten is also incredibly dense. At 19.3 g/cm3, its density is 1.7% higher than that of direct. This means that a smaller quantity of the metal weighs considerably more than greater amounts of less dense materials.

As a consequence, the metal is a great alternative when it will come to ballast – specifically for racing automobiles and plane. Its density also tends to make it perfect for use as a radiation shield.

Tungsten’s density is similar to that of gold, so jewellery designed from this significantly less high priced metal is significantly preferred.

Tungsten conducts energy really well, earning it the excellent material for the fabrication of electrical parts this kind of as electrodes, conductors and metallic movies.

Last but not least, the metal is prized for its corrosion-resistance. Thanks to its potential to endure saltwater devoid of becoming corroded, it is frequently employed in the shipbuilding and fishing industries. It can be conveniently applied outside for prolonged intervals of time, and is also resistant to solvents and acid.

Products and Solutions of Distinctive Metals

Distinctive Metals can fabricate and offer a range of high quality tungsten products, like tungsten wire and tungsten bar, as effectively as billets, sheets, crucibles and plenty of other products besides.

As effectively as tungsten, we supply products made from molybdenum, tantalum, niobium, zirconium and titanium.

You can also get in contact with us to use our expert expert services – such as machining, welding, aqua blasting, bead blasting and the fabrication of wrought products and alloys.

Regardless of whether you know particularly what you are looking for, or you are still creating your specification, do not hesitate to get in touch with Unique Metals to talk to for our suggestions and direction.

For even further information, only get hold of our knowledgeable crew now applying our useful on the net speak to sort. We will be happy to assist you.

Fibre Lasers – Working Principles, Applications & More

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Lasers have been around for a long time but their use in commercial applications is quite recent. It took engineers a while to strengthen laser capabilities to a point where they could compete with traditional manufacturing methods in terms of cost, time and ease of use.

The fibre laser technology, for instance, was first developed back in the 60s. Back then, this technology was still in its nascent phase. Only in the 1990s did it become fit for commercial use. Since then, the technology has come a long way in terms of its applications and efficiency. In the 60s it was possible to only generate a few tens of milliwatts, today we have fibre lasers that can generate over 1000 watts with reliable final properties.

In this article, we will discuss how a fibre laser works, where it is used and why it is often the optimal choice when compared to alternatives. But first, let us understand what it is.

What Is a Fibre Laser?

Fibre lasers are a type of solid-state lasers that use optical fibres as their active gain medium. In these lasers, a fibre made of silicate or phosphate glass absorbs raw light from the pump laser diodes and transforms it into a laser beam with a specific wavelength.

To achieve this, the optical fibre is doped. Doping refers to the practice of mixing a rare-earth element into the fibre. By using different doping elements, laser beams can be created with a wide range of wavelengths.

Some common doping elements in their increasing order of emitted wavelengths are neodymium (780-1100nm), ytterbium (1000-1100nm), praseodymium (1300nm), erbium (1460-1640nm), thulium (1900-250nm), holmium (2025-2200nm), and dysprosium (2600-3400nm).

Because of such a wide range of produced wavelengths, fibre lasers are perfect for a variety of applications such as laser cutting, texturing, cleaning, engraving, drilling, marking and welding. This also enables fibre lasers to find use in many different sectors such as medicine, defence, telecommunications, automotive, spectroscopy, electrical, manufacturing and transportation.

How a Fibre Laser Works

Schematic diagram of fibre laser

A fibre laser is named after its active gain medium which is an optical fibre. Any fibre laser machine that produces a well-collimated high-power laser does it in five main stages. These are as follows:

  • Creation of pump light

  • Collection and travel into the optical fibre

  • Pump light passes through the optical fibre

  • Stimulated emission in the laser cavity

  • Amplification of raw laser light into a laser beam

Creation of pump light

This is where the energy for the laser beam enters the system. In fibre lasers, we use electricity as the energy source. Diodes known as pump laser diodes convert electrical energy into light energy. In high-quality diodes, the conversion is reliable and efficient and produces light energy only with specific wavelengths.

Incidentally, low-quality laser diodes were one of the major obstacles that impeded the progress of laser technology for about 3 decades.

In most cases, this pump light or pump beam is produced in parts by multiple laser diodes and is then coupled in the fibre optic cable. For instance, there are 20w laser machines that combine pump light from 11 laser diodes in the fibre optic cable.

Collection and travel into the optical fibre

A coupler combines the light from multiple laser diodes into one. This coupler is a part of the optical fibre. It has multiple entry points on one side, each of which connects to a fibre from an individual laser diode.

On the other side, there’s a single exit point that connects to the main fibre. Once all the light is collected, it travels to the laser medium or the gain medium.

Pump light passes through the optical fibre

Total Internal Reflection in Optical Fibres

Total Internal Reflection in Optical Fibres

In the next stage, the laser diode’s light flows through the optical fibre to the laser medium. The fibre consists of two main components: the core and the cladding. The core is made of silica glass and provides the pathway for light. This core is covered by cladding. When the light reaches the cladding, all of it is reflected back into the core.

Fibre lasers invariably lose some power through heat, but the excellent surface area to volume ratio facilitates effective heat dissipation leading to very little heat-related wear and tear.

On further travel through the optical fibre, the light eventually reaches the doped part of the fibre. This part is known as the laser cavity.

Stimulated emission in the laser cavity

When the laser diode light reaches the doped fibre, it strikes the rare earth element’s atoms and excites its electrons to a higher energy level. In time, this leads to a population inversion which is necessary for the production of a standard laser.

Population inversion in laser refers to the state of a gain medium in which a greater number of electrons are in an excited state compared to those that are not. It is called population inversion because this is the opposite of the normal state where only a few atoms have excited electrons.

When some of these electrons naturally fall to lower energy levels, they emit photons of only a specific wavelength. These photons interact with other excited electrons, stimulating them to emit similar photons and retreat to their initial lower energy levels. This is the physical process of “stimulated emission” that is a part of the acronym LASER (Light Amplification by Stimulated Emission of Radiation).

The electrons that return to their original relaxed state are re-excited by the incoming light from pump diodes. Eventually, the process reaches an equilibrium between the excited and relaxed electrons, giving us a steady flow of raw laser light. This light needs to be refined for it to be used in different applications.

Amplification of raw laser light into a laser beam

Before using the raw laser light from the doped fibre in applications, it has to be strengthened first. In fibre lasers, this is done by using Fibre Bragg Gratings (FBGs). These gratings replace conventional dielectric mirrors by acting as mirrors of varying reflectivity.

The light jumps back and forth between the Bragg Grating. A portion of the laser light passes through in one direction while the remaining light is reflected into the laser cavity. The part that passes through the grating becomes the laser beam. This beam is then sent through an oscillator (and sometimes a combiner) to improve coherence and then delivered as output.

Fibre Laser vs CO2 Laser

The main difference between these two processes is the source where the laser beam is created. As explained earlier, fibre laser source is silica glass mixed with a rare-earth element. On the other hand, CO2 laser source is a mixture of gases with CO2 being the main component.

Fibre lasers beat CO2 lasers almost on every front except the initial investment cost. For instance, CO2 lasers cannot cut many materials that are reflective. Fibre lasers handle better a greater number of those reflective metals such as copper, brass, aluminium and stainless steel. A fibre laser also requires less power and provides higher efficiency. All this at half the operating costs and five times the cutting speed of a CO2 laser (when cutting thin metals).

Although when cutting thicker materials (above 5mm) CO2 lasers are still generally preferred, the constant advances in fibre laser technology are widening the instances where this technology has the edge. Thus currently, it makes sense if your laser cutting service provider has access to both of these types of machines to accommodate different projects in an efficient way.

A fibre laser also provides better beam quality, higher reliability, lower carbon footprint, faster startup time, longer service life and remote processing capabilities. It also requires less maintenance as there are no mirrors or lenses involved. Mirror alignment on CO2 laser machines usually requires a professional or special training of the operator.

It also does not require a ceramic marking compound for laser engraving like a CO2 laser does. Although fibre lasers require a greater initial investment when compared to CO2 lasers, they are still a more cost-effective solution in the long run due to the lower Total Cost of Ownership (TCO).

Fibre Laser Applications

Due to the wide range of possible power outputs, fibre lasers are effectively used in many different applications. Some of these are:

Laser marking

Generally, ytterbium-doped fibre lasers with an emission wavelength of 1064 nm are considered perfect for laser marking applications. These lasers can mark plastic and metals with permanent, high-contrast marks. OEMs, as well as suppliers, require laser marking machines for part identification such as barcodes, logos or other texts.

These machines may be manual or automated and can be customised to keep up with short production cycles. In addition to marking, fibre laser equipment can be used for annealing, etching and engraving.

Laser cleaning

Fibre lasers can effectively clean metal surfaces of paint, oxide, rust, etc. This process is known as laser cleaning. The process can be automated and customised for different production line parameters.

Laser welding

Another important application for these lasers is in welding services. Fibre laser welding is one of the most promising upcoming technologies that is gaining market share fast due to the various benefits the process offers. Laser welding provides faster speeds, greater precision, lower deformation, higher quality and efficiency compared to traditional methods.

Laser cutting

Laser cutting is one of the most researched areas of fibre laser application. It can handle complex cuts with impressive edge quality. This makes it optimal for parts with close tolerances. Its adoption is increasing across the board with fabricators due to its long list of benefits. Let us take a look at what these are in the next section.

Fibre Laser Cutting Benefits

Compared to other laser types, a fibre laser has several characteristics which make it ideal for wider commercial use. We have divided these benefits into four categories:

Process benefits

  • Greater stability

  • High efficiency

  • Superb beam quality

  • Easy integration

  • Non-contact process

  • Faster speeds (though, CO2 lasers cut faster in a straight line)

  • Safer as the beam is absorbed more readily preventing reflection damage

Cost benefits

  • More cost-effective in the long run

  • High energy efficiency (~75%, the number for CO2 lasers is ~20%)

  • Reduced wastage

  • Reduced power usage

  • Reduced operator redundancy

  • Low operating cost

Equipment benefits

  • Scalability

  • Versatility across industries

  • More compact with a smaller footprint

  • Long service life

  • No periodic mirror realignment

  • Reduced set-up and downtimes

  • Eliminated tooling charges

Part quality benefits

  • Less heat damage to details

  • Material diversity

  • Better edge quality

  • Lower residual stresses

  • Reduced part contamination

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