Example analysis of material selection and surface

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Example analysis of die steel material selection and surface treatment

we are the production department of a hardware factory in Shenzhen, starting from the standpoint of automobile manufacturing and development. Last year, we began to produce digital camera shell parts for a foreign manufacturer

in the production process, we have encountered some problems that affect the production efficiency. In the process of punching parts, due to the wear failure or fracture of the punching needle of the die used for punching, and there is a great randomness, it is necessary to shut down and change the needle more frequently, which will affect the production. To this end, we tested two kinds of die steel, asp23 from Sweden and SKD11 from Taiwan. Asp23 has high hardness, so it is not easy to wear, but its toughness is slightly poor before consolidation; SKD11 has good toughness and is not easy to fracture, but its hardness is low and it is easy to wear out. In terms of price, asp23 is significantly more expensive than SKD11. Asp23 costs hundreds of yuan per kilogram, and SKD11 costs dozens of yuan per kilogram

in order to better improve the performance of die punching needle, we have found many companies engaged in surface treatment. Among them, a company in Shenzhen plated titanium nitride (TIN), and a Hong Kong company plated diamond-like carbon (DLC) film. In addition, a Beijing company also provided amorphous diamond (ta-C) film for demonstration projects. We are all familiar with titanium nitride (TIN). It is a mature technology and has a wide range of applications. In recent years, the application of diamond-like carbon (DLC) film is also gradually rising, and amorphous diamond (ta-C) coating is a new technology. For the test results of three companies, we made a comparison: the effect of titanium nitride (TIN) plated parts is not obvious, which is not as advertised in the market; The effect of diamond-like carbon (DLC) film plating is slightly better than that of titanium nitride (TIN); We are quite satisfied with the effect of amorphous diamond (ta-C) coating. During the first amorphous diamond (ta-C) coating test, the average life of all SKD11 plated parts was increased by 3 times, and the average life of asp23 plated parts was increased by 1 time, and the increase of the life of all plated parts was very average. Generally, the new technology has the problem of unstable process. In order to verify the stability of this technology, we conducted a second test, This time, mold steels made of asp23 and SKD11 were also used, and the number of plated parts was more than that of the first test. The test results surprised us. The average life of asp23 plated parts was increased by 2 times, while the average life of sdk11 plated parts was increased by nearly 7 times. For this, we asked the company's technicians, who explained that the coating process was optimized and adjusted, so the coating effect was better

because the cost of SKD11 is significantly lower than that of asp23, and the coating effect is better than that of asp23, we adopted the SKD11 coating product provided by this surface treatment company in Beijing

later, we asked the technicians of this company in Beijing why the effect of diamond-like carbon (DLC) and titanium nitride (TIN) was not ideal. They said that their technical working temperature was at room temperature, usually lower than 80 ℃, while the film-forming temperature of diamond-like carbon (DLC) and titanium nitride (tin) was usually a few Baidu. The higher temperature made the steel produce annealing or tempering effect, reducing the quality of the original steel; The adhesion between the film and the substrate is also an important factor affecting the effect. Diamond like carbon (DLC) and titanium nitride (TIN) coatings are usually deposited by chemical vapor deposition (CVD), and the film is only deposited on the surface of the plated part. The amorphous diamond coating adopts advanced surface ion activation technology, so that the coating goes deep into the surface of the substrate, and the bonding force between the film and the substrate is significantly improved. During the stamping process, the film is not easy to fall off; In terms of surface hardness, the hardness of diamond is higher than that of titanium nitride (TIN). At this time, the content of pure diamond in the manual measurement mode can be switched to more than 70%, and the content of diamond-like carbon film is usually only 20%, up to 60%. Therefore, the hardness of amorphous diamond-like carbon film is the highest among the three; In terms of surface finish, the friction coefficient of amorphous diamond film is less than 0.10, titanium nitride (TIN) film is 0.55, and diamond-like carbon (DLC) film is 0.15

after the use of amorphous diamond film punching needle, we carried out the coating test of tap. The test results are as follows: the effect of coating on tap with oxide layer is not obvious, while the service life of tap without oxide layer coating is increased by 3 times on average, and the effect is obvious

traditional technology has its advantages, mainly because the process is mature and stable, but the test results let me realize that new technology requires us to try, and will bring unexpected results. (end)

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