Thermal spray is used to help protect materials during the manufacturing of industrial equipment. Applying thermal spray is often one of the last steps in the manufacturing process. Thermal spray goes by several names. Some refer to is as plasma, flame, HVOF, or arc spray. Usually, thermal spray coating is used during the manufacturing of metal equipment. However, it can also work on plastics.
The Most Versatile Spray
Manufacturers often choose thermal spray for their coating because it can be used on a variety of different metal and platic substrates. It is also an excellent replacement for plating. It is just as good, if not better than, nickel weld and chrome plating and overlay.
Thermal spray also offers a thicker barrier. The thickness can depend on how the thermal spray is applied, and the materials that the thermal spray is made out of. usually, it offers a shield that is .002 to .025 inches deep.
What Does Thermal Spray Do?
Thermal spray can enhance the material it is applied to. It often results in a better performance when the material that’s been treated with thermal spray is put to work. The spray also offers protection to the component.
Are There Different Types Of Thermal Spray?
Thermal spray can come in different forms. HVOF, and arc spray coating are not just alternative names for thermal spray. They’re also descriptive. HVOF is used to melt and apply metals that have much higher melting points then the materials spread with arc spray. That’s because a HVOF sprayer has the ability to melt with components with combustible oxygen.
Coating With Metal Makes The Product Cheaper And Durable
Metals can be expensive. To slash production cost, it’s often wise to have materials coated with metals and plastics, rather then making them out of it. That’s mainly why manufacturers use thermal sprays. Metals add a lot of strength to a product. Stainless steal can make a product practically unbreakable.
Why Is It Called Thermal Spray?
Thermal spray gets its name because it uses heat to liquidize metals and plastics so they can be sprayed onto a material. These metals and plastics are usually, but not always, in powder form before they’re melted. They’re then sprayed onto a surface at an extremely high velocity. This allows the product to stay liquid until it has reached its target.
Who Uses Thermal Spray?
People who are in the field of welding often use thermal spray to finish products, materials and equipment they’re producing. Those who use thermal spray have some sort of technical education which allows them to utilize it safely and efficiently. It can be hazardous to those who have not been trained.
A Lot Of Equipment And Products Are Treated With Thermal Spray
You may not realize it, but it’s likely you see something everyday that’s been treated with thermal spray. If you work in an office building, some of the components of that elevator you use have been treated by sprayed materials. Thermal spray is an important industry practice that’s used to complete the objects and equipment we depend on.
Arc spraying is an important process that provides a variety of benefits over similar techniques – and in this guide we’re going to reveal some of the key uses of the arc spraying technique. With this in mind, let’s get straight to it.
First of all, perhaps one of the biggest benefits of arc spraying is the fact that it’s highly resistant to corrosion, which means it can be used in situations that simply wouldn’t be suitable for an alternative technique. Now, let’s take a look at the many uses that arc spraying is useful for.
1 – Wind turbines
As you may expect, wind turbines are vulnerable to corrosion due to their exposure to the environment in all weathers – and this makes them perfect candidates for the arc spraying technique. In fact, most manufacturers of turbines will finish them with a resilient blend of zinc and aluminum alloy that provides unrivaled protection towards corrosion. Of course, it also renders a wonderful finish, too.
2 – Bridges
Similar to wind turbines, a bridge is often exposed to severe weather – and for safety reasons – it needs to be tough and resilient at all times. In general, thermal spraying techniques are used to finish the platform structures of most bridges, with the application of thermal sprayed aluminum, via the process of arc thermal spraying. The spray will instantly solidify on contact with the surface, and leave a dense coating that should last for many years to come.
3 – Petrochemical plants
Another popular use for arc spraying is within petrochemical plants, where the process is favored over any alternative due to the incredible resilience and durability it offers, especially when it comes to corrosion. One of the biggest maintenance costs for any petrochemical plant is something known as ‘corrosion under insulation’ that occurs when the effects of corrosion are increased under wet insulation.
Of course, the arc spraying technique provides a powerful way to resist corrosion, which ultimately means the expensive piping systems used in these plants will last longer without needing maintenance or complete replacement.
4 – Movies sets
One of the most interesting and unusual uses for this technique is to finish polystyrene props that are commonly used on movie sets. While these items may lack a great deal of realism when they’re seen up close, with the use of an arc-sprayed metallic finish, it’s possible to achieve an incredible level of realism at a very cost-effective price.
In general, the polystyrene will be finished with a combination of steel and zinc, which gives the prop improved strength, as well as making it resistant to the bumps and scrapes it’s likely to incur while it’s being used on a movie set.
Overall, it’s safe to say that the arc spraying process is a key technique in a variety of industries, and thanks to it’s fantastic anti-corrosion properties, it’s one of the most important finishing techniques used in the modern world. So if you’re considering the possibility of using this technique for your project, you’ll be making a great decision.
Are you looking for the best technique for material coating? If so, you’ve probably done at least a bit of research about the different thermal spray processes. Each comes with its advantages and disadvantages. Plasma spraying has become increasingly popular over recent years, thanks to the versatility it offers. With this thermal spray process, you have plenty of controls and it allows you to have a coating that offers far superior performance compared to other types of thermal spray procedures.
The three basic states of matters are thoroughly discussed in grade school. But there’s a fourth state of matter called plasma. It’s a gas that has become tremendously hot. Plasma closely resembles the look of gas, but it has distinct properties that set it apart. Most notably, plasma is capable of conducting electricity. Thanks to advancements in technology, new coating systems can use this energy for plasma spray coatings.
There are several advantages to choosing plasma coatings over other thermal spray processes. One primary advantage is that it can be used for virtually any type of material. For instance, ceramics requires a great amount of energy to transform into a desirable coating. This shouldn’t be an issue with the plasma spray process because the powder materials can reach an astonishing 16,500 degrees Celsius.
As mentioned, this thermal spray procedure also offers a great level of versatility and control, allowing for the deposition of a wide variety of spray materials. These include alloys, metals, and ceramics. Plasma coatings offer outstanding resistance to corrosion, extreme temperatures, and abrasion. There are also coatings with non-stick qualities.
The versatility of plasma coatings extends to the type of materials for which it can be used. Since the substrate’s temperature can be controlled, overheating shouldn’t be a problem. This is a huge advantage compared to other types of thermal spray processes in which the substrate could overheat and cause the object being coated to get damaged or distorted.
The plasma spray process is particularly known for creating ceramic coatings. Plasma coatings are extremely durable and resistant to wear and tear. Extreme temperatures aren’t an issue as well. In this regard, the plasma spray process far outperforms other spraying solutions such as anodizing and chroming. Ceramic coatings provide a diverse range of finishes as well, allowing you to choose the one that best matches your needs.
Plasma spray solutions can be all you need to protect your products or the parts in your manufacturing plant that are prone to wear. Regardless of the industry, you’re in; you can guarantee that the plasma spray process can be used to offer a high level of protection for your products.
As a well-established coating process, you can’t go wrong by choosing plasma as your go-to thermal spray solution. It’s widely available, and you should have no problems finding a company that offers this type of coating. Just be sure that the company you choose has the necessary equipment to produce high-quality plasma spray coatings that comply with different application requirements.
High-velocity oxygen Fuel, abbreviated as HVOF, is a thermal spray coating process that is quite common nowadays. HVOF is the same process as the combustion spray process/LVOF only that it has been developed to give out a high spray velocity. It is used for the manufacture of high grade and dense layers of carbides. It is a distinct thermal spray covering process where the powder particles are transported to a workpiece at high velocity using a gas or oxygen flame. This process generates a layer that is attached to the surface at a molecular level. The result is a dense homogeneous layer that has a very high bond strength.
The gas and oxygen flame with a temperature of almost 3000 degree Celsius hits the workpiece with powder flecks like tungsten carbide. The flame travels at a speed of over 1000 meters per second, a speed nearly five times the rate of a conventional thermal spray. High velocity oxygen fuel thermal spraying makes the production of very dense and homogeneous coverings that have low internal stresses, high adhesion value and high bond strength possible, which is ideal for a linear.
Well, there are several types of HVOF guns that employ various methods to achieve the high velocity spraying. The first method is high-pressure water-cooled (high-velocity oxygen-fuel) combustion chamber with a long nozzle. In this process, oxygen and fuel are fed into a chamber, and the combustion produces a high-pressure flame that is then forced down the nozzle. Another method employs a simpler system of an air cap and a high-pressure combustion nozzle. Oxygen and the fuel gas are supplied at high pressure, and combustion happens outside the nozzle. However, this happens within an air cap fed with compressed air. This compressed air accelerates the flame and ideally works as a coolant for the gun.
As you can already guess, there are two obvious differences between conventional thermal spraying and HVOF coating. HVOF employs confined heating along with a longer nozzle to heat and speed up the covering material that is in the form of a powder. The conventional thermal spray devices work at Hypersonic gas acceleration. Extreme velocities give higher energy, and this leads to HVOF coating sprays being more dense and long lasting.
The technology seen in High-Velocity Oxygen Fuel thermal spraying is among the most important processes employed in applying carbide based coating. High velocity oxygen fuel(HVOF) has been changing from gas-fueled towards liquid fueled systems.
So, What Are The Benefits HVOF Coating?
First and foremost, it gives a stronger bond of 10,000 psi or more.
The particle velocity of this process achieves less porosity and fewer oxides.
The quality and the mass of the coatings gives the ability to obtain Ra finishes of 8 or even less.
Depending on the type of High-Velocity Oxygen Fuel spray that is being applied, an RC-quality of above 60 can be obtained through this process.
Tungsten Carbide spray coatings through HVOF thermal process have the best resistance to wear and distress.