In recent years, the rapid development of CNC machining technology has promoted basic scientific research on CNC tool structure and the development of new products. There are many types and specifications of cutting tools for CNC machine tools produced by major manufacturers in the world, and the quantity is often dazzling and confusing. Now we briefly describe the essentials of popular science knowledge about CNC cutting tools and new products, technological status and development trends in the fields of CNC cutting tool materials, structures, and applications in recent years, so as to understand and master relevant new CNC cutting tool product information. The main points.
1. Brief classification of CNC cutting tools
2. Current technological status and development trends of new CNC tool material products
1. Overview:
In recent years, the results of basic scientific research on CNC tool materials and new products have been concentrated in the fields of high-speed (ultra-high-speed), hard (including heat-resistant, difficult-to-machine), dry, and fine (super-precision) CNC machining technologies. The research and development of new tool material products are based on superhard materials (diamond, surface modified coating materials, TIC-based cermets, cubic boron nitride, Al203, Si3n4-based ceramics), W, CO-based coatings and fine particles (super The fields such as fine particles) cemented carbide matrix and Go-containing powder metallurgy high-speed steel are progressing rapidly.
2. In the field of superhard materials:
Diamond (brazed polycrystalline, single crystal) tools have been rapidly used in high-hardness, high-strength, difficult-to-machine non-ferrous gold (alloys) ) and non-ferrous metal-non-metal composite material parts in the high-speed, efficient, dry (wet) mechanical cutting industry. Its overview is as follows:
Automobile and motorcycle industry: polycrystalline, artificial single crystal diamond face milling cutters, boring tools, turning tools, reamers, composite (combination) hole processing and other CNC tools, etc. Largely used in automatic production lines of high-strength, high-hardness Si--Al alloy parts;
Bamboo flooring, furniture industry: polycrystalline, CVD thick film deposition diamond (composite sheet) end mills, three-sided Cutting tools such as edge forming milling cutters and face milling cutters are being widely used in automatic production lines for high-hardness composite bamboo wood flooring, furniture, doors and windows, etc.;
Aviation, aerospace, automobile and electronic information technology industries : Diamond CVD film-coated CNC tools (mainly solid WCO carbide tools) are mostly used in milling, turning, drilling, reaming and countersinking to process high-strength aluminum alloys (casting, forging), fiber-metal layers Plates, carbon fiber thermoplastic composites, magnesium alloys, graphite, ceramics... and other components meet the technical requirements of high speed, long life, and dry machining. Various manufacturers are constantly improving diamond coating technology to improve the bonding fastness and density of diamond films and tool substrates;
Fine (super-precision) machining technology field: single crystal natural and artificial diamond tools It is used in fine (ultra-precision, nano-level) turning processing of various precision instrument lenses, mirrors, computer disks, copy machine (video recorder) drums, etc.;
Single crystal diamond tools are also used in Fine cutting of ophthalmic cornea surgery and fine engraving of printing plates... and other industries.
Various manufacturers are constantly improving the sharpening technology, sharpening accuracy and sharpening efficiency of various types of diamond tools.
●Surface modification coating materials mainly include: TiN, TiCN, TiALN, ALTiN, Al2O3, CrN, ZrC, MoS2, WS2...etc., using computer-controlled PVD, PCVD, and CVD coating process technologies. The above coating materials are used for end mills, reamers, drill bits, composite (combination) hole processing tools, gear hobs, gear shaper cutters, shaving cutters, forming pull (push) cutters and various machine clamps that can be indexed The surface modification coating treatment of the blade (the base material is high-speed steel, WCo-based cemented carbide, and Ti-based cermet) meets the requirements of high-speed, long-life cutting and processing of high-strength, high-hardness cast iron (steel), forged steel, stainless steel, and titanium. The production technology of workpieces made of alloys, nickel alloys, magnesium alloys, aluminum alloys, powder metallurgy, bamboo, etc. has different requirements. Tool surface modification coating technology has the characteristics of low cost and quick results for greatly improving the cutting performance of CNC tools. This technology can flexibly change coating materials according to various cutting processing technical requirements. The technology is relatively excellent.
Various manufacturers are continuously improving coating process technology, improving coating materials and developing nano-scale multi-functional coating materials, aiming to continuously improve the coating bonding fastness, wear resistance, impact toughness, etc., and strive to expand the scope of applications.
●Ti-based cermets (TiCN series) various machine-clamped indexable turning tools, boring tools, reamers, milling cutters, composite (combination) hole processing CNC tools and integral vertical (ball) CNC tools such as head) milling cutters and reamers are being used in automatic production lines of high-strength, high-hardness cast iron (steel) alloys, forged steel alloys, quenched steel alloys, heat-resistant alloys, and powder metallurgy parts to meet the needs of high-speed, high-efficiency, Technical requirements for hard, dry (wet) precision machining. Various manufacturers are using different trace elements and sintering process technologies to develop new cermet material products, aiming to continuously improve their bending strength, impact toughness, and wear resistance. Japan's cermet cutting tools already account for 30% to 40% of the total carbide cutting tools. In the world, the application scope of this type of cutting tools is also showing a trend of rapid expansion.
●Cubic boron nitride polycrystalline composite sheet milling cutter (face milling cutter, corn tooth end milling cutter, ball end milling cutter), boring cutter, turning tool, reamer, composite (combination) hole Machining and other CNC tools (brazing and machine clamp indexable structures) are widely used in automatic production lines of high-strength, high-hardness cast iron (steel) alloys, forged steel alloys, quenched steel alloys, powder metallurgy and other parts to meet the needs of High-speed, efficient, hard and fine machining technology requirements.
●Al203, Si3N4 based ceramics (whisker toughened type), various machine clamps, indexable turning tools, milling cutters and other CNC tools are used in high strength, high hardness, wear-resistant cast iron (steel) , forged steel, high manganese steel, quenched steel, powder metallurgy, engineering plastics, wear-resistant composite materials and other parts production lines to meet the technical requirements of high-speed, efficient, hard and dry machining. Currently, various manufacturers are developing new medium- and fine-grained ceramic materials and functionally graded (multiphase) ceramic material products by adding different trace elements and innovative production technology to Al203 and Si3N4-based ceramic materials, aiming to continuously improve their flexural strength. , impact toughness.
3. W, CO type coatings and fine particle (ultrafine particle) cemented carbide materials:
W, CO type fine (medium) particle carbide matrix The material is developed by adding various trace elements to adapt to the coating process technology requirements of various surface modified coating materials, and to meet the cutting performance requirements of various machining process technologies for indexable inserts; ultra-fine particle carbide The research and development and application of base materials are divided into two aspects: in the electronics and information technology industries, micro drills and end mills are used to process fiber-metal composite laminate material workpieces. The base materials are developed in the direction of high toughness, and the surface is coated with a diamond film. To increase the surface hardness and wear resistance of the tool; in the mold industry, aircraft, steam turbine, automobile... and other manufacturing industries, it is used for cutting and processing high-strength, high-hardness cast iron (steel), forged steel, aluminum alloy (casting, forging), powder metallurgy CNC tools such as integral vertical (ball head) milling cutters, special extrusion tools, reamers (Φ30mm
4. Leading field of Co-containing powder metallurgy high-speed steel materials:
Innovative powder metallurgy high-speed steel (containing Co) based on improved pulverization, hot pressing process, and adding trace elements Materials, made into various forming broaches (integral, combined), high-speed hobs, shaving (inserting) gear cutters, taps, corrugated edge end mills, forming end mills and rolling (extrusion, rolling) tools , widely used in manufacturing industries such as cars, motorcycles, aero engines, steam turbines, etc., to process high-strength, high-hardness cast iron (steel) alloys, alloy structural steel (forging), heat-resistant alloy steel, stainless steel, and overall aluminum alloys (hot forging) ), high Si--Al alloy material workpieces. According to the different requirements of cutting processing technology, its surface is coated with coating materials such as TiN, TiCN, TiALN, CrN, MoS2, ZrC... to meet the technical requirements of high-speed, efficient, hard precision machining.
CNC tool materials are a relatively active field of materials technology. The launch of each new product will bring machining technology to a new level. Manufacturers have always attached great importance to the research and development technology in this field.
3. Current status and trends of scientific and technological development of new structures and new varieties of CNC cutting tools
1. Overview:
In recent years, the scientific and technological achievements of CNC cutting tools are mainly reflected in In terms of developing multiple cutting functions in one tool and improving its cutting performance, it can adapt to the technical requirements of high-speed (ultra-high-speed), hard (including heat-resistant, difficult-to-machine), dry, fine (super-precision) cutting and high-efficiency CNC machining. With the advancement of part blank manufacturing technology, the geometric dimensions and cutting allowance control of part blanks are more precise. The research and development of new structures and new varieties of CNC tools are mainly concentrated in the light and medium load cutting range, and special hole processing, broaching, rolling The five types of cutting tools (extrusion, rolling), milling and turning are undergoing relatively active changes, and their corresponding insert chip-breaking geometries are being developed accordingly.
2. CNC tool system:
In recent years, there has been an international development trend of using "HSK" tool system to gradually replace other types of tool systems developed by various manufacturers. Developed countries in Europe follow the German DIN69893-1 HSK tool system standard, and the International Standardization Organizing Committee formulated the ISO/DIS standard for it. The HSK tool system has the characteristics of high dynamic and static stiffness, good positioning (rotation) accuracy, and high allowable rotation speed (≤150000p.r.m). It not only facilitates planning and tool management, but also saves tool costs and reduces production costs overall. It was first used in machining centers, CNC boring and milling machines, and gradually expanded to various types of lathes (turning centers), grinders (grinding centers), CNC special machines and CNC machining automatic production lines. The scope of use covers almost all tool fields.
3. Hole processing tool category:
Among the tool categories, hole processing tools are a large family with endless small improvements and innovations. Here are its main prominent new structures , The new varieties are briefly described as follows:
● CNC drill bits:
Integral drill bits: The cutting edge of the drill tip is improved from a symmetrical linear type to a symmetrical arc type (r=1/2D ) to increase the cutting edge and improve drill tip life; the drill core is thickened to improve the drill body rigidity, and the "S"-shaped chisel edge (or spiral center edge) is used to replace the traditional chisel edge to reduce axial drilling resistance and improve Chisel edge life; using stepped drill tips with different apex angles and negative chamfers to improve chip separation, chip breaking, drilling performance and hole machining accuracy; inlaid with modular hard (superhard) material tooth crowns; cooling in the oil hole and Large helix angle (≤40°) structure, etc. Recently, integral fine-grained ceramic (Si3N4) and Ti-based cermet material drill bits have been developed.
Machine-type drill bit: The drill tip adopts a rectangular special-shaped symmetrical cutting edge, the drilling force is radially self-balanced, the indexable insert replaces other geometric shapes, and the drilling force is radially balanced overall. Indexable inserts to reduce drilling vibration and improve drill tip self-centering performance, service life and hole machining accuracy.
● Composite (combined) hole processing CNC tool:
It integrates the new structure and new technology of drill bit, reamer, hole expansion (countersinking) tool and extrusion tool, and is integrated , machine-clamp type, special composite (combination) hole processing CNC tools are developed very quickly. Generally speaking: the use of inlaid modular hard (super-hard) material cutting edges (including tooth crowns), internal cooling of oil holes, large spiral grooves and other structures is its current development trend.
● CNC reamer:
The structure of large helix angle (≤45°) cutting edge, edgeless extrusion reaming and oil hole cooling is its overall development direction. The maximum reaming hole diameter has reached φ≤400mm.
● Boring tools:
Single-edge fine-tuning precision boring tools are being replaced by multi-edge expansion (countersinking) hole cutters, reamers and special CNC tools for compound (combination) hole processing. A CNC intelligent precision boring tool has been developed abroad that uses the axial movement of the push-pull rod inside the tool system or the movement of the balance slider with high-speed centrifugal force to complete the boring of spherical surfaces (curved surfaces), inclined surfaces and reverse cutting of the back of parts in one pass. It represents The development direction of boring tools.
● Tap:
A tap with a large helix angle (≤45°) has been developed. Its cutting cone is designed with special edge inclination and rake angle depending on the soft and hard conditions of the material being processed. wait.
● Hole expansion (countersinking) cutter:
The structure of multi-blade, equipped with various CNC tool handles and modular adjustable micro tool holder is the current hole expansion (countersinking) tool. development direction.
4. CNC milling cutters:
Integral end mills: The side edges of carbide end mills adopt a large helix angle (≤62°) structure. The over-center edge of the head is often in the shape of an arc (or spiral center edge) with a negative edge angle, which increases the length of the cutting edge and improves cutting stability, workpiece surface accuracy and tool life. Adapt to the requirements of CNC high-speed and stable three-dimensional space milling processing technology.
Machine-clamped end mills: Side teeth, end teeth and over-center teeth composed of various types of machine-clamped end mills that are composed of indexable inserts (often equipped with three-dimensional chip breaking grooves) The blade end teeth (all short cutting edges) can meet the technical requirements of CNC high-speed and stable three-dimensional space milling processing.
CNC milling cutters have been manufactured using computer-aided design, cutting simulation and CNC machining technology.
Machine-clip CNC face milling cutter: The cutter body tends to be made of lightweight and high-strength aluminum and magnesium alloys. The cutting edge adopts a large rake angle, negative edge angle, and indexable inserts (with various geometric shapes). ) with three-dimensional chip breaking groove.
CNC milling cutters and special composite hole machining tools all apply high-speed rotating body dynamic balancing and safety clamping technology. Some high-speed rotating cutter bodies also apply aerodynamic principles and use cyclone cooling cutting edges. During dry cutting, the temperature of the cutting edge is reduced and the tool life is improved.
5. Turning tools,
Grooving and cutting-off turning tools have developed a multifunctional tool that can handle end face, outer circle, profiling, grooving, cutting and chamfering. Turning tool, the insert clamping method adopts an inlaid elastic cutter body and a self-fixing structure of cutting force, which is very practical and novel.
6. Broaching tools:
With the support of modern CNC machining technology, various special outer contour precision forming, combination broaches and turning-drawing combined forming and drawing tools have been developed. Cutting tools, equipped with special CNC machine tools. The batch production efficiency of some automobile workpieces is increased dozens of times, and the product quality and accuracy are very stable.
7. Other cutting tools:
The batch production process of small module involute external gears and spline shaft parts specially used for automobiles and motorcycles adopts rolling and rubbing extrusion without chips. Processing technology, special tools and special CNC machine tools have been developed, which can increase the batch production efficiency of specific workpieces dozens of times, and the quality and accuracy are very stable.
IV. Conclusion
The innovative results of broaching, rolling, extrusion tools and composite (combination) hole processing CNC tools often lead to huge changes in machining concepts. Innovative scientific and technological achievements in the field of integrated tool materials and special CNC machine tools have also produced huge social and economic benefits.
In recent years, the rapid development of technology for NC processing technology of NC machine tool structure of basic scientific research and new product research and development. All major manufacturers of the world many kinds of cutter for NC machine tool production, specifications, the large number of often dizzying, to no avail. Now the NC cutting tools of science knowledge and application in recent years CNC tooling materials, structures, new product, present situation and development trend of science and technology in areas such as its essentials, this summary as described, numerical control tool to understand the relevant new product information. Classification brief second, NC, CNC tool material new product overview of the current situation and development trend of science and technology 1,: in recent years, the results set for basic scientific research and new product CNC cutting tool materials in high speed (high speed), hard (including heat-resistant and hard machining), dry, fine (Super fine) CNC machining technology. Tool material new product research and development of superhard materials (surface modification of diamond, coating materials, TIC-based metal ceramic, CBN, Al203, Si3n4 ceramic base class), w, CO classes, coatings and fine particles (ultrafine particles) Go-containing powder metallurgy high-speed steel and cemented carbide substrate areas of progress more quickly. 2, super hard materials: Diamond (brazing polycrystalline, monocr
ystalline) tool was quickly applied to high hardness, high strength, difficult to process color gold (alloy) and non-ferrous metals-non-metallic composite material parts and components of high speed, high efficiency, dry (wet) in the mechanical machining industry. Their profiles are as follows: automotive and motorcycle industry: polycrystalline, synthetic single crystal diamond face milling cutters, boring, turning tools, reamers, composite (combined) holemaking NC cutting tools are used, such as Si--Al of high strength , high hardness alloy parts on automatic production line; Bamboo flooring and furniture industry: poly Crystal, CVD diamond thick film deposition (PDC) Mills, three side milling cutters, cutters, and other such tools are widely used in high hardness combined with bamboo wood floors, furniture and door forth Parts on automatic production line; Aviation, aerospace, automotive and electronic and information technology industry: CVD diamond thin film coated CNC tool (WCO class cemented as a whole) applied to milling, turning, drilling, reaming and with feedout heads machining high strength aluminum alloy (casting, forging), fiber-metal plates, carbon fiber reinforced thermoplastic composite material, magnesium alloys, graphite, ceramics forth Parts for high speed, high life expectancy, dry machining technology requirements. All the manufacturers are constantly developed diamond coating process technology, improving the fastness and the combination of d
iamond-like carbon films with tool substrate density; Fine (superfinish) machining technology: single crystal lens with natural and synthetic diamond cutters used in precision instruments, mirrors, computer disks, copiers (VCR) drum SB Work fine (Super fine and nanometer) turning; Single crystal diamond cutting tool has also been applied to the eye cornea surgery fine cutting and fine printing plate engraving sth And other industries. Manufacturers are constantly improving grinding technology of diamond cutting tools, sharpening ...