Manufacturers often maximise different metals and alloys to generate quality parts and products. They likewise carry out various processes so that their parts and products will obtain the needed qualities.

Most parts and products that are processed by manufacturers often boast improved qualities for the subsequent processes. Those that have undergone quenching may become hard but brittle. Cold working metals can then make them stronger but more difficult to deform. But once the parts and products have achieved the needed final qualities, they are often subjected to processes that enhance their surface.

One great process that enhances the surface of metal parts and products is black oxide coating.

A Quick Introduction to Black Oxide Coating

Black oxide coatingis the process of changing the surface of a metal part or product through a chemical treatment. This process often applies an extra layer of protection to the part or product that is mostly made from stainless steel, copper, copper-based alloys, zinc, powdered metal, and silver solder.

The process of black oxide coating can generally enhance the corrosion resistance and appearance of the part or product. It can likewise minimise light reflection. 

Conducting the Black Oxide Coating Process

Black oxide coating can be done in three ways.

  1. Hot Bath: Black oxide coating through a hot bath can be achieved by dipping the product into various tanks while frequently placing it in water. Once the dipping process is done, the porous top layer of the product is applied with oil. The application of oil improves the corrosion resistance of the product. 
  2. Mid-Temperature Bath: Mid-temperature bath may be conducted similarly to the hot bath, but it does not release the same amount of toxic fumes as the latter. Through a mid-temperature bath, the product’s surface is expected to be converted to magnetite at a lower temperature. 
  3. Cold Coating: Cold coating, ultimately, is done by the application of a copper selenium compound to the product at room temperature. Compared to the hot bath, the cold coating does not require tons of chemicals and a hot environment just to conduct the black oxide coating process. Enhancing the corrosion resistance of the product can then be achieved by applying oil or wax to its surface.

Advantages of Black Oxide Coating Process

The black oxide coating process can bring tons of benefits to the products being processed by manufacturers. With this process, the products can effectively become more resistant to corrosion and abrasion. Black oxide coating can also add an appealing decorative finish to the products. It is even cheaper and more affordable than other finishing processes. Another great advantage of the black oxide coating process is that it allows manufacturers to process many products in one go.

To know more about black oxide coating, you can call us at Alpha Detroit Heat Treatment. We provide a wide range of services for all your heat treatment needs. Our expertise allows us to suggest the most appropriate process for your heat treatment requirements.

Tons of industries maximise tools and products that are made from metal parts and components. But before they can be processed further, they must all be subjected to heat treatment first.

Heat treatment is a process wherein the properties of the metal materials are strengthened and improved. This specific process is often conducted by putting them in various heating and cooling operations. Most of the time, heat treatment activities can easily relieve the stresses of the parts, allowing them to be machined or welded easily. Other changes that heat treatment activities can introduce to the materials are increased strength, wear resistance, and improved electric and magnetic properties.

Various metals can attain these qualities. One of these metals is aluminium.

Common Properties of Aluminium

Aluminium is known to be the most abundant metallic element on the planet, which makes it one of the most utilised nonferrous metals today.

As stated, this specific metallic element belongs to the classification of nonferrous metal, which means that it does not contain appreciable amounts of iron. This specific quality makes aluminium more resistant to rust and corrosion compared to ferrous metals. Aside from its respectable corrosion resistance, aluminium is also notable for its high ductility, valuable hardness, high malleability, excellent conductivity, and appealing looks.

To make aluminium more useful for industrial applications, it will often be mixed and combined with other elements. Some elements that can be added to aluminium are copper, magnesium, silicon, and zinc. The addition of elements further improves its strength, workability, corrosion resistance, and conductivity.

The Importance of Stress Relieving

One heat treatment activity that can be utilised in processing aluminium parts and products is stress-relieving. Stress-relieving is a heat treatment activity that subjects the aluminium to a constant temperature below its critical temperature. After the heating process, the aluminium parts or products will then be exposed to controlled cooling. Through stress relieving, any accumulated internal or residual stresses that they possess will be removed. 

Internal or residual stresses often come from previous manufacturing processes. Without removing these stresses, the aluminium parts or products may deform, corrode, or experience fatigue. 

Other types of stresses that this particular heat treatment activity deals with are structural stress and thermal stress. Structural stress is defined as the tensile strength of the material whenever it is under applied conditions or forces. Thermal stress, alternatively, develops whenever an extremely high temperature is present, which can lead to metal contraction or expansion.

Stress Relieving Aluminium Parts

Different operations can be conducted to ensure that aluminium parts can relieve unnecessary stresses. 

One of these operations is annealing. During annealing, the aluminium materials will be exposed at a temperature of around 50% of their melting point. With annealing, their microstructures are expected to change, leading to the reduction of hardness, increase in ductility, and elimination of internal stresses.

Another operation that can relieve unnecessary stresses of aluminium parts is solution heat treatment. This operation is done by soaking the parts in a high-temperature solution before quenching them. Any dissolved elements will be trapped and precipitated out, leading to an age-hardening effect.

To know more about stress-relieving aluminium, you can call us at Alpha Detroit Heat Treatment.

Many heat treatment processes are designed to effectively heat metal materials without exposing them to melting temperatures before cooling them. The activities involved in these processes are intended to obtain certain mechanical properties of the materials. Some of the materials may become more malleable, while others may become stronger, more ductile, or more resistant to abrasion.

One heat treatment process that is popular to manufacturers today is the salt bath heat treatment.

Salt bath heat treatment is a process wherein treated parts or components will be immersed into a molten salt or salts mixture. What is great about this specific process is that it can provide a faster heating setup. It can likewise provide adequate control over the cooling conditions of the parts as well as low surface oxidation and decarburisation. Some applications associated with salt bath heat treatment are as follows:

Aerospace Industry

One of the most common applications associated with salt bath heat treatment involves the aerospace industry. Through salt bath heat treatment, various parts and components of aeroplanes can become resistant to fatigue. They can likewise become more durable against damaging elements present in the surroundings, especially at high speeds. Some aerospace parts that can take advantage of the salt bath heat treatment process are helicopter frame parts, aeroplane engine components, and many more.

Automotive Industry

Just like the aerospace industry, the automotive industry can likewise maximise the advantages present with salt bath heat treatment. The process of salt bath heat treatment does not only make parts resistant to fatigue, but it can also make them resistant to chemicals and high temperatures. Some of the most notable parts of vehicles that can take advantage of salt bath heat treatment are gears, axles, fasteners, camshafts, crankshafts, and other metal parts and components.

Electronics Industry 

The parts needed for various machines and equipment pieces to run effectively must be made from materials that are durable, reliable, and long-lasting. Without these types of materials, they could easily reach the end of their service life and even risk dangers to the people using them. Heavy machines, in particular, are often made from parts out of iron, steel, titanium, nickel, copper, and aluminium. Through salt bath heat treatment, these materials can be processed so they can be strong and dependable.

The process of salt bath heat treatment and its associated benefits become possible thanks to its utilisation of a salt bath furnace. Through the addition of nitrates, nitrites, chlorides, carbonates, cyanide, and caustic soda, the process can ensure that parts and components will become wear-resistant, durable, and long-lasting. Salt bath heat treatment likewise ensures that the parts and components can be utilised again in other manufacturing steps, which cannot be done by other processes.

To know more about salt bath heat treatment, you can contact us at Alpha Detroit Heat Treatment. Our expertise allows us to suggest the most appropriate process for your heat treatment requirements.

Businesses under the metalworking industry can opt for a wide array of processes to ensure that their products can attain notable properties and characteristics. One of these processes is hardening.

Hardening is a metalworking process that can increase the hardness of metal products. This process is normally conducted by exposing the products to a specific amount of heat before proceeding with controlled cooling. The main purpose of increasing the metal products’ hardness is to ensure that they obtain higher resistance to plastic deformation.

Two types of hardening processes that can be utilised in working with metal products are case hardening and induction hardening.

Case Hardening

Case hardening is a hardening process that exposes metal workpieces to carburisation. This process is done by heating the workpieces to over 880°C so they can become austenitic. Subsequently, a carbon-emitting medium will transfer the coal to the workpieces so they can receive more carbon without affecting their carbon density. The transfer of carbon, which is known as carburisation, enables the hardening of the workpieces. Once the workpieces have completed the carburisation process, they will be annealed to restore their much-needed plasticity.

The primary purpose of case hardening is to increase their surface hardness and vibration resistance while retaining their ductile and elastic core microstructure. This process can ensure that metal products can boast increased lifetime, enhanced wear-resistance, and improved flexibility and weldability, making them useful under stressful conditions. Some notable applications of case hardening include the production of cooking utensils and the reinforcement of metal girders.

Induction Hardening

Induction hardening, on the other hand, entails the heat treating, quenching, and annealing of workpieces separately. The parts are exposed to an electromagnetic alternating field through a current-carrying coil. The field used for the induction hardening can produce eddy currents, which are known for flowing in the opposite direction to the currents that generate heat. Once the parts are placed inside the coil, they are then heated within or above their transformation temperatures before exposing them to the quenching process. This specific process is monitored by a control system to yield great results.

The primary purpose of induction hardening is to increase the mechanical properties of metal workpieces. One of the advantages of induction hardening is that it can increase the wear resistance of the workpieces. The workpieces are likewise expected to gain increased strength and fatigue life once induction hardening is applied. Workpieces can also be tempered even after the induction hardening process so their hardness level can be adjusted on the fly.

Both case hardening and induction hardening can be beneficial for industries that want high-quality metal workpieces. To know more about these processes, you can contact us at Alpha Detroit Heat Treatment. We provide a wide range of services for all your heat treatment needs. Our expertise allows us to suggest the most appropriate process for your heat treatment requirements.

Metal workpieces often undergo numerous processes to obtain substantial changes in their properties. One of these processes is the heat treatment process.

Heat treatment is a term used to describe activities that can alter the physical properties of a metal workpiece. This specific process typically involves heating or cooling in introducing changes to the involved part or component. Some properties that are affected by the heat treatment process include hardness, ductility, strength, toughness, and resistance to elements.

One great thing about the heat treatment process is that it can be done in numerous ways. It can even be done in various locations, ensuring that a workpiece can obtain its needed changes.

Issues with Heat-Treating Metal Workpieces

Before its processing, a metal workpiece is often exposed to various surrounding elements such as oxygen, carbon dioxide, and moisture. And with prolonged exposure to these elements, the metal workpiece may obtain changes and reactions, especially if it is processed with intense heat.

Now, to minimise undesirable reactions, professionals would often eliminate the source of the reactive elements from the heat-treating environment. One way of doing this is to replace the air in the heat-treating chamber with nitrogen, argon, or other gas combinations. Another way would be the exposure of the metal workpiece in a non-reactive molten salt bath. These processes may deter most of the undesirable reactions from the elements, but the workpiece would still contain low levels of impurities.

Vacuum Heat Treatment is the Key Solution

Vacuum heat treatment, fortunately, can remove most of the reactive elements from the heat-treating environment or heat-treating chamber. With the help of a vacuum pumping system, it can get rid of most air elements inside the heat-treating chamber that cause undesirable reactions and discolouration to the workpiece. Sometimes, an oil diffusion pump is installed alongside the pump system so that it can further eliminate elements and allow more sensitive metal workpieces to be heat treated.

The furnaces used for the vacuum heat treatment, however, can only be effective if they are maintained regularly. Without proper maintenance, they might develop some leaks, which can only lead to contamination during the heat treatment process.

The Processes of Vacuum Heat Treatment

Vacuum heat treatment starts with the positioning of the workpieces in a special chamber. With a vacuum pumping system and other related components, the elements inside the chamber will be removed and replaced with argon gas or other similar elements. Once these steps are done, the chamber will be subsequently heated up to as much as 1,300 degrees Celsius before lowering it for some time. The entire cycle of the vacuum heat treatment may take three hours to one day, depending on the needed material.

A fully maintained vacuum heat treatment furnace can easily produce workpieces with boosted strength and improved thermal efficiency. It can likewise avoid oxidation, decarburisation, and carburisation.

To know more about this process, you can call us at Alpha Detroit Heat Treatment.

Sources:

Benefits of vacuum heat treatment. Jones Metal Products. (2020, June 11). https://www.jmpforming.com/blog/vacuum-heat-treating/benefits-of-vacuum-heat-treatment.htm.

MetalTek International. (2021, June 2). Heat Treatment | Metal Processing. MetalTek. https://www.metaltek.com/capabilities/heat-treatment/

VAC AERO International. (2019, May 15). Why Heat Treat in a Vacuum?Vacaero. https://vacaero.com/information-resources/vac-aero-training/650-why-heat-treat-in-a-vacuum.html