1 Introduction In recent years, in order to reduce the weight of aircraft and auto parts, the use of aluminum alloy has increased year by year. Although the cutting resistance when machining aluminum alloy is smaller than that when cutting steel, since the aluminum alloy is relatively soft, the blade edge of the tool blade is likely to be viscous during cutting, thereby affecting the surface roughness of the workpiece to be processed. In order to increase the strength of the aluminum alloy material, a large amount of silicon is usually added to the aluminum alloy. However, since the silicon element is dispersed in the form of particles in the aluminum alloy material, and the hardness of these silicon particles is high (about 1000 HV), the cutting edge of the tool may be severely worn during the cutting process. Therefore, such a high silicon aluminum alloy material is a material that is very difficult to machine.
The single crystal diamond turning tool can be used for precision turning of aluminum alloy to obtain good surface quality. When machining high-silicon aluminum alloy materials, diamond tools can prevent tool wear caused by silicon particles in the material, resulting in a longer tool life. If a single-crystal diamond is used to manufacture a blade having a spiral groove and a complicated shape, the milling of the aluminum alloy material can also obtain a satisfactory effect. On the one hand, due to the high price of single crystal diamond, on the other hand, the three-dimensional shape of the milling cutter blade is complicated, and the geometrical dimensional accuracy is high. If single crystal diamond is used, the forming process of the milling cutter blade is very difficult, so the single crystal diamond is used. Milling cutters have not been widely used.
In recent years, many research institutes and tool manufacturers at home and abroad have conducted a lot of research on the development and application of synthetic diamond coating technology, and have achieved many new results. The synthetic diamond coating technology has developed rapidly in hard alloy milling. A large number of applications have been applied to the surface coating of tools such as knives, drills, taps, and blades. The successful application of synthetic diamond coating technology has made synthetic diamond coated knives popular, and the market demand is increasing year by year. Despite this, synthetic diamond coated tools have disadvantages: although diamond is the hardest substance in nature, its toughness is very low, so it is easy to cause film brittleness when processing difficult materials. In addition, synthetic diamond film is diamond grain. The polycrystalline body has a rough surface, and the rough surface affects the roughness of the surface of the aluminum alloy workpiece to be processed, and the aluminum alloy adheres easily in the pit portion, resulting in early wear of the diamond film.
In order to solve the above problems, Japan OSG Co., Ltd. recently developed ultrafine crystal diamond coating technology and successfully applied it to the coating of milling tools.
2 Cutting performance of ultra-fine crystal diamond coated milling cutter In order to study the cutting performance of ultra-fine crystal diamond coated milling cutter, ultra-fine crystal diamond coated milling cutter and uncoated superhard milling cutter are processed by cutting test. The advantages and disadvantages of surface roughness, anti-adhesion and film toughness were analyzed and compared.
2.1 Surface roughness to be processed The synthetic diamond coating is a diamond polycrystalline aggregate in which crystal nuclei (fine diamond particles) are formed on the surface of the substrate and crystal nuclei grow in a columnar shape. The surface of the diamond-coated film is uneven, and the surface roughness is usually Ry 4 to 10 μm. When a diamond-coated cutting tool is used to process an aluminum alloy, the uneven surface shape affects the roughness of the surface to be processed, so that it is difficult to obtain a smooth surface that is expected to be finished. Although the uncoated superhard alloy tool can obtain a relatively smooth surface, the blade edge will cause a sticking phenomenon in a short process, which will affect the surface roughness of the workpiece and cause early wear of the blade. Less than expected life. The ultrafine crystalline diamond film developed by OSG is not only flat and smooth, but also has a very good gloss on the surface of the ultrafine crystal diamond film coated milling cutter compared with the surface of a conventional diamond coated milling cutter.
The aluminum alloy material A7075 was subjected to a cutting test using an ultrafine crystallized diamond coating φ10 mm double-edged milling cutter. The cutting conditions were: line speed 200 m/min, cutting feed rate 0.05 mm/blade, and cutting depth 0.1*10 mm. The test results show that the surface of the machined aluminum workpiece has the same level of finish as the surface of the uncoated superhard milling cutter.
2.2 Anti-adhesiveness Diamond tools have excellent anti-adhesion properties when dry-cutting aluminum alloys. Metal compound films (such as TiN, TiCN, TiAlN, CrN, etc.) have good processing characteristics, but the film wears quickly during the cutting process. After the film is worn, the surface shape changes or even the surface of the substrate is exposed, thereby causing adhesion of the aluminum alloy. The diamond-coated tool wears very little when processing aluminum alloy, and has good anti-adhesion and good cutting performance after long-term use.
Dry-cut roughing tests were performed on aluminum alloy ADC12 (12% Si content) using a diamond-coated superhard alloy milling cutter and an ultrafine crystal diamond coated cutter. The cutter diameter is φ10mm, and the cutting conditions are: line speed 300m/min, cutting feed rate 0.15mm/blade, and cutting depth 2.5*8mm. During the test, the superhard alloy milling cutter without diamond coating was stuck at the tip of the cutting edge at the beginning of the cutting process, the discharge of the chip was greatly affected, and the chip was clogged in the groove, and the sticking phenomenon was gradually serious; and the ultrafine crystallization occurred. The diamond film coated milling cutter has white marks rubbed by the aluminum alloy only at the tip end portion without sticking.
The tool life comparison test was carried out under the above cutting conditions. The uncoated cemented carbide milling cutter could not be used after a short time of cutting due to the sticking phenomenon; the ultrafine crystal diamond coated milling cutter was cutting. It can continue to be used after the length reaches 700m. It can be seen that the ultrafine crystal diamond coated tool has very good cutting performance for dry cutting of aluminum alloy.
In addition, the ordinary diamond film has coarse crystals and uneven surface. When dry-cutting the aluminum alloy, the tool coated with the diamond film is likely to adhere to the concave portion between the crystal grains and the crystal grains, thereby reducing the processing precision of the material to be processed. And surface roughness. On the other hand, the surface roughness of the ultrafine crystal diamond film was less than Ry1 μm, and no adhesion occurred in the cutting test.
2.3 Film toughness Since the ordinary diamond film is a polycrystalline aggregate formed by growing a crystal nucleus on the surface of the substrate and growing along the columnar shape, fine cracks are easily formed between the columnar grain boundaries to cause damage of the film. The ultrafine crystal diamond film has a small crystal grain, which can effectively prevent the expansion of fine cracks and thus has high toughness.
Wet cutting test of aluminum alloy ADC12 was carried out by ordinary diamond film coated milling cutter and ultrafine crystal diamond film coated milling cutter. The cutting conditions were: linear speed 400m/min, cutting feed rate 0.05mm/blade, cutting depth 0.1 *10mm. After the cutting test with a cutting length of 1108 m, the tip of the ordinary diamond film coated milling cutter was chipped; the ultrafine crystal diamond film milling cutter had only a little wear and the blade remained in a good state.
3 Conclusions The ultrafine crystal diamond film coating developed by OSG has excellent cutting performance. It has been proved by cutting test that the ultrafine crystal diamond film coated milling cutter has excellent anti-adhesion and high adhesion when milling aluminum alloy. Machining accuracy, durability and film toughness. Due to the defects of ordinary diamond film coating, ultrafine crystal diamond film coating technology has been widely used in diamond coating cutting tools developed by OSG and has been favored by more and more users.
The single crystal diamond turning tool can be used for precision turning of aluminum alloy to obtain good surface quality. When machining high-silicon aluminum alloy materials, diamond tools can prevent tool wear caused by silicon particles in the material, resulting in a longer tool life. If a single-crystal diamond is used to manufacture a blade having a spiral groove and a complicated shape, the milling of the aluminum alloy material can also obtain a satisfactory effect. On the one hand, due to the high price of single crystal diamond, on the other hand, the three-dimensional shape of the milling cutter blade is complicated, and the geometrical dimensional accuracy is high. If single crystal diamond is used, the forming process of the milling cutter blade is very difficult, so the single crystal diamond is used. Milling cutters have not been widely used.
In recent years, many research institutes and tool manufacturers at home and abroad have conducted a lot of research on the development and application of synthetic diamond coating technology, and have achieved many new results. The synthetic diamond coating technology has developed rapidly in hard alloy milling. A large number of applications have been applied to the surface coating of tools such as knives, drills, taps, and blades. The successful application of synthetic diamond coating technology has made synthetic diamond coated knives popular, and the market demand is increasing year by year. Despite this, synthetic diamond coated tools have disadvantages: although diamond is the hardest substance in nature, its toughness is very low, so it is easy to cause film brittleness when processing difficult materials. In addition, synthetic diamond film is diamond grain. The polycrystalline body has a rough surface, and the rough surface affects the roughness of the surface of the aluminum alloy workpiece to be processed, and the aluminum alloy adheres easily in the pit portion, resulting in early wear of the diamond film.
In order to solve the above problems, Japan OSG Co., Ltd. recently developed ultrafine crystal diamond coating technology and successfully applied it to the coating of milling tools.
2 Cutting performance of ultra-fine crystal diamond coated milling cutter In order to study the cutting performance of ultra-fine crystal diamond coated milling cutter, ultra-fine crystal diamond coated milling cutter and uncoated superhard milling cutter are processed by cutting test. The advantages and disadvantages of surface roughness, anti-adhesion and film toughness were analyzed and compared.
2.1 Surface roughness to be processed The synthetic diamond coating is a diamond polycrystalline aggregate in which crystal nuclei (fine diamond particles) are formed on the surface of the substrate and crystal nuclei grow in a columnar shape. The surface of the diamond-coated film is uneven, and the surface roughness is usually Ry 4 to 10 μm. When a diamond-coated cutting tool is used to process an aluminum alloy, the uneven surface shape affects the roughness of the surface to be processed, so that it is difficult to obtain a smooth surface that is expected to be finished. Although the uncoated superhard alloy tool can obtain a relatively smooth surface, the blade edge will cause a sticking phenomenon in a short process, which will affect the surface roughness of the workpiece and cause early wear of the blade. Less than expected life. The ultrafine crystalline diamond film developed by OSG is not only flat and smooth, but also has a very good gloss on the surface of the ultrafine crystal diamond film coated milling cutter compared with the surface of a conventional diamond coated milling cutter.
The aluminum alloy material A7075 was subjected to a cutting test using an ultrafine crystallized diamond coating φ10 mm double-edged milling cutter. The cutting conditions were: line speed 200 m/min, cutting feed rate 0.05 mm/blade, and cutting depth 0.1*10 mm. The test results show that the surface of the machined aluminum workpiece has the same level of finish as the surface of the uncoated superhard milling cutter.
2.2 Anti-adhesiveness Diamond tools have excellent anti-adhesion properties when dry-cutting aluminum alloys. Metal compound films (such as TiN, TiCN, TiAlN, CrN, etc.) have good processing characteristics, but the film wears quickly during the cutting process. After the film is worn, the surface shape changes or even the surface of the substrate is exposed, thereby causing adhesion of the aluminum alloy. The diamond-coated tool wears very little when processing aluminum alloy, and has good anti-adhesion and good cutting performance after long-term use.
Dry-cut roughing tests were performed on aluminum alloy ADC12 (12% Si content) using a diamond-coated superhard alloy milling cutter and an ultrafine crystal diamond coated cutter. The cutter diameter is φ10mm, and the cutting conditions are: line speed 300m/min, cutting feed rate 0.15mm/blade, and cutting depth 2.5*8mm. During the test, the superhard alloy milling cutter without diamond coating was stuck at the tip of the cutting edge at the beginning of the cutting process, the discharge of the chip was greatly affected, and the chip was clogged in the groove, and the sticking phenomenon was gradually serious; and the ultrafine crystallization occurred. The diamond film coated milling cutter has white marks rubbed by the aluminum alloy only at the tip end portion without sticking.
The tool life comparison test was carried out under the above cutting conditions. The uncoated cemented carbide milling cutter could not be used after a short time of cutting due to the sticking phenomenon; the ultrafine crystal diamond coated milling cutter was cutting. It can continue to be used after the length reaches 700m. It can be seen that the ultrafine crystal diamond coated tool has very good cutting performance for dry cutting of aluminum alloy.
In addition, the ordinary diamond film has coarse crystals and uneven surface. When dry-cutting the aluminum alloy, the tool coated with the diamond film is likely to adhere to the concave portion between the crystal grains and the crystal grains, thereby reducing the processing precision of the material to be processed. And surface roughness. On the other hand, the surface roughness of the ultrafine crystal diamond film was less than Ry1 μm, and no adhesion occurred in the cutting test.
2.3 Film toughness Since the ordinary diamond film is a polycrystalline aggregate formed by growing a crystal nucleus on the surface of the substrate and growing along the columnar shape, fine cracks are easily formed between the columnar grain boundaries to cause damage of the film. The ultrafine crystal diamond film has a small crystal grain, which can effectively prevent the expansion of fine cracks and thus has high toughness.
Wet cutting test of aluminum alloy ADC12 was carried out by ordinary diamond film coated milling cutter and ultrafine crystal diamond film coated milling cutter. The cutting conditions were: linear speed 400m/min, cutting feed rate 0.05mm/blade, cutting depth 0.1 *10mm. After the cutting test with a cutting length of 1108 m, the tip of the ordinary diamond film coated milling cutter was chipped; the ultrafine crystal diamond film milling cutter had only a little wear and the blade remained in a good state.
3 Conclusions The ultrafine crystal diamond film coating developed by OSG has excellent cutting performance. It has been proved by cutting test that the ultrafine crystal diamond film coated milling cutter has excellent anti-adhesion and high adhesion when milling aluminum alloy. Machining accuracy, durability and film toughness. Due to the defects of ordinary diamond film coating, ultrafine crystal diamond film coating technology has been widely used in diamond coating cutting tools developed by OSG and has been favored by more and more users.
Basic Cage Accessories,Street Lamp Parts,Light Pole Rebar Cage,Light Pole Base Rebar Cage
Jiangsu Yunya Optoelectronics Technology Co., Ltd. , https://www.yunyalighting.com