In many cases, cold spray tools or products have replaced hot spray applications for many different types of drilling and workers need to be aware of the cold spray dangers. The hot spray uses compressed air or nitrogen to quickly and efficiently spray metal into tight areas with enough force to bend the tool to the metal being drilled.
This unique feature of the hot spray also called a solid-state technique, allows the efficient processing of soft metals which are more susceptible to crack during the thick rapid crystallization of hot metal. For more details on Cold Spray and why it’s a first choice for many, please follow the link.
Although this process does not allow a large temperature increase in the drill bit, the ability to use the cold spray to rapidly apply an adequate cool heat to drill into the hard to reach places makes this method a popular choice among drill operators.
Because of the fast-acting nature of the cold spray, the work can continue while the cold spray cools down the working parts. The cold spray uses the application of a high-pressurized gas to rapidly accelerate metal particles on a substrate.
The gas used will be one that has been specifically designed for the application process to ensure that it provides a superior result over the hot method. Often called a “lubricated gas,” this kind of gas has the potential to provide a higher degree of molecular attraction than other lubricants commonly used for the application of pressure to metal materials.
With the proper pressure and temperature, the fast molecules of the cold spray can attach themselves to any metallic surface including stainless steel, brass, copper, aluminum, and even zinc. The substrate of the cold spray is typically a hard rubber or plastic-like material.
The feedstock, also typically rubber or plastic-like material, is the actual material that will be injected into the holes drilled by the cold spray equipment. The feedstock is usually a mixture of polyethylene and acrylic resins, with it usually being a liquid or gas such as argon, krypton, xenon, or nitrogen.
When selecting an appropriate feedstock, you should look for a material that will have the highest thermal conductivity possible. This will ensure that the cold spray dyes can maintain a constant temperature throughout the deposition process. Additionally, the thickness of the feedstock will impact the speed with which the dye molecules are deposited.
The more layers the feedstock has, the faster the temperature of the coating and therefore the faster the dye will be deposited onto the substrate. Depending upon the job need, you may need to conduct additional research in order to determine the correct feedstock thickness and material specification.
During the cold spray process itself, you will find that different methods are utilized to deposit the color and/or metal oxide onto the substrate. One method commonly used is known as the direct application technique. This technique uses a small electrical current to transfer an electric blue dye through a small hole.
The fluorescent dyes are deposited on the metal by electrochemical means and this method is generally a good choice for coated metal alloys, aluminum, copper, brass, stainless steel, and nickel. Another option for coating is the transfer method wherein gas molecules are used. The gas used here is generally argon, neon, or krypton.
This method is used for coating metallic foils, plastics, and other non-metallic materials. The gas used here is responsible for giving the coating its elasticity because it absorbs the incident particles that are released during the spray application. A third method used in cold spray applications is called supersonic particle deposition (SPD).
Using this powdery coating, you have the ability to cover a wide range of alloys, plastics, and even ceramics. The powdery coating thickness will depend on the particular alloy and the manufacturer’s specific needs.
All these are just some of the instances when cold spray technology is being utilized. In metallurgical applications, the cold spray technology has been very helpful in making things easier and cost-effective. Aside from that, it gives you a chance to create precise and accurate results as you do your job.
There are also many companies that have seen the huge benefits these kinds of metallurgical techniques can bring to their company. Whether it is for coating metals or other purposes, this is one type of technology that will surely help you make things easier and cost-effective at the same time.