Talking about the problems existing in the popularization of thermal spraying technology

       Recently, there are many consultation calls from all walks of life. Facing the questions and concerns of customers, I will make a summary here.



1. Most customers do not understand the thermal spraying process and think that the thicker the better. Too much of anything is a good thing, for different products, the requirements are different, the thickness is 0.05-0.5, I spray the thickness of 1.5 mm, but there are special cases. I recommend a thickness of no more than 0.3.



2. Thermal spray bonding strength is not high. This bonding strength is only a relative concept, not a concept. Using high-performance supersonic spraying equipment, the bonding strength should be at least greater than 60MPa. What is this concept? 1MPa=10kg/cm2, which means that it can withstand a tensile force of 600 kg per square centimeter, so in general, such bonding strength is sufficient. The big problem is the brittleness of the thermal spray coating. The toughness of the same nickel-based alloy, spray welding and spray coating is very different, which is determined by the process itself. Therefore, the thermal spray coating will not have impact, hardness, and bond strength problems, which are the problems of the process itself.



3. Thermal spraying is too expensive. The reason for the high price is:



1) The price of raw materials is high, and the prices of the same raw materials in the market will vary greatly. We use domestic brand products with strict ingredient control, stable quality and high price.



2) When spraying powder, the powder output rate is low. Some people say that you are not using imported equipment, why the deposition rate is low. Due to the fast flow of the flame of the imported equipment and the serious rebound, the deposition rate is lower than that of the domestic equipment.



3) The use cost is high. Imported equipment uses oxygen and jet fuel and costs much more per hour than domestic equipment.



4) Expensive accessories. All imported equipment accessories are imported, and the loss of accessories is higher than that of domestic equipment.

5) High labor cost. Our crews need more skills, not only to operate spray equipment, but also to program robots.

6) Equipment depreciation is high. Both imported equipment and robots are close to 2 million units, and the price of robots equipped with many domestic equipment will not be less than 100,000 units.



Therefore, the cost of using imported equipment is higher than that of domestic equipment. Many low-end products only need domestic equipment, and more products need imported equipment to meet the requirements.



4. Low-end spraying enterprises have caused adverse consequences. Some customers have used spray paint before, but because the industry is more complicated. Some spraying companies do not have advanced equipment and strong technology, and they brag too much about the performance of the coating. As a result, they fail to meet the requirements for use, causing many customers to directly suspect that it is a technical problem. Some domestic spraying equipment has poor performance. The same sprayed tungsten carbide coating has a bonding strength of only 20 MPa or more and a hardness of only HV800. Such a tungsten carbide coating is not as wear-resistant as nickel-based alloys.



5. The customer cannot accept this price. The spraying company reduces the price in order to accept the order, but can only reduce the quality to gain profits. Everyone knows you get what you pay for, and some customers just like to keep prices down. We all understand the consequences of this, and such consequences are passed on to customers and affect their use. The customer's use effect is not good, and it is suspected that it is a technical problem. In fact, the analysis is that the money is not in place. Similar sprayed tungsten carbide, there are 2,000 yuan a square, 12,000 yuan a square, if you choose 2,000 a square, you need to ensure the quality, this is a joke.



6. Not all products are available. Although thermal spraying technology is widely used and has strong applicability, it cannot be used in some working conditions. Thin-walled parts, small parts, sharp edges, and impact parts are not suitable for spraying.