Posted by: jasonagnes at 03:07 AM | No Comments | Add Comment
Post contains 9 words, total size 1 kb.

Posted by: jasonagnes at 07:06 AM | No Comments | Add Comment
Post contains 9 words, total size 1 kb.

Cemented carbide(hardmetal) is a general term for alloys composed of carbides, nitrides, borides, or silicides of high melting point metals (W, Mo, Ti, V, Ta, etc.). Divided into two major categories of casting and sintering. The cast alloy has high brittleness and low toughness, and has little practical application value. Widely used are sintered alloys, which are generally sintered from tungsten carbide or titanium carbide and cobalt powder and have high hardness, wear resistance and hot hardness. Mainly used to manufacture high-speed cutting and processing of hard materials, in recent years, the use of carbide in the mold industry is also increasing, so it is of practical significance to discuss and study the hard alloy heat treatment.1. Features of Cemented CarbideCarbide is made by the method of powder metallurgy from the refractory metal hard compound and the metal bonding phase. The commonly used hard compounds are carbides. As the hard alloy for cutting tools, commonly used WC, TiC , TaC, NbC, etc., the binder is Co, and the strength of the cemented carbide mainly depends on the content of Co. Because the carbide in the cemented carbide has a high melting point (Carbide Turning Insertssuch as a melting point of 3140° C. of Ti C), a high hardness (such as a hardness of 3200 HV of TiC), a good chemical stability, and a good thermal stability, the hardness and wear resistance thereof are high. Sex and chemical stability are much higher than high-speed tool steels. The commonly used cemented carbide hard phase is mainly WC, which has good wear resistance. Although some carbides have similar hardness as WC, they do not have the same wear resistance. WC has a higher yield strength (6000 MPa), so it is more resistant to plastic deformation. WC’s thermal conductivity is also good, and thermal conductivity is an important performance index of the tooling. WC has a lower coefficient of thermal expansion, about 1/3 of that of steel; its modulus of elasticity is 3 times that of steel, and its compressive strength is also higher than that of steel. In addition,gun drilling inserts WC has good resistance to corrosion and oxidation at room temperature, good electrical resistance, and high bending strength.Fig.1 The quasi-equilibrium diagram of WC-Co alloy2. Heat treatment and alloy organizationIt has been studied on the bonding phases of WC-Co alloys with different C/W ratios of 5% to 35% WC. The conclusions are drawn as follows: γ-phase or (γ+WC) phases are generated in the alloy at slow cooling; When there are (γ+η) phases appear. However, since the (γ+η) phase is unstable, the (γ+η) phase will transform into a stable (γ+WC) phase after annealing. According to the test results, the quasi-equilibrium phase diagram shown in Fig. 1 is drawn (the solid line is the phase diagram of the stable system, and the dashed line is the local phase diagram illustrating the η characteristics of the quasi-stable phase). The annealing (slow cooling) of the typical cemented carbide depends mainly on the carbon content: when C/W>1, the free carbon precipitates on the WC-Co phase boundary; when the C/W<1, the microstructure of the alloy has In both cases: One is in the three-phase region (WC + γ + η). It is inevitable that the η phase appears after the alloy is slowly cooled. If such a large amount of η phase exists in the cementitious phase, branched crystal grains appear, and the small grains are unevenly distributed; if there is a large grain of η phase, the grains are separated by a long distance, so there is information that the η phase is Higher temperatures have begun to form. In the other case, when the alloy is in the two-phase (WC+γ) region, the W alloy will be precipitated as Co3W from the bonding phase after the low-carbon alloy is annealed. The reaction process can be expressed by the following formula. Co Face-centered cubic → Co Face-centered cubic + Co3W Therefore, this low-carbon two-phase WC-Co alloy will be transformed into a three-phase (WC + γ + CoW) structure after annealing. Figure 2 shows the dissolution curves of W for two-phase WC-Co alloys at different annealing temperatures. The curve is the critical temperature curve for two-phase alloys transformed into three-phase (WC+γ+CoW) alloys: above the curve temperature Annealing results in a two-phase microstructure alloy; annealing at temperatures below the curve yields a three-phase structure containing Co3W.3. Effect of heat treatment process on mechanical properties of hardness alloy(1) Effect on Strength Since WC has different solid solubility at different temperatures in Co, it provides the possibility of precipitation hardening of the binder phase by solid solution temperature quenching and subsequent aging. Quenching can inhibit the precipitation of WC and the homotropy transition of Co (Co dense hexagonal, Co face centered cubic). It has been reported that the strength of the alloy containing 40% cobalt can be increased by about 10% after quenching, but the strength of the alloy containing 10% cobalt is reduced after quenching. Considering that the amount of cobalt contained in cemented carbides commonly used in engineering is generally 10% to 37%, the effect of heat treatment on the alloy strength is very small. So someone dared to assert that quenching is not a way to increase strength for W-Co alloys. Annealing also causes a decrease in the strength of the alloy, as shown in Tables 1 and 3. The properties of tungsten carbide vary with the amount of Co contained and the thickness of the grains, as shown in Figure 4.Fig. 2 The solid solubility curve of tungsten in WC-10%Co two-phase alloyFig.3 Effect of annealing at 800°C on the flexural strength of WC-10%Co contentTable 1 Effect of annealing at 650 °C on bending strength of WC-11% Co alloy(2) Effect on Hardness When WC-Co alloy ages, Co3WCX and Co3WCX precipitate in dense tissue phase, so the hardness of the alloy will increase, but the hardness of the alloy will decrease when it is subsequently converted to Co3W. The H.Jonsson test data is shown in Figure 5 and Figure 6. Although the existence of Co3WCX after heat treatment slightly improves the hardness of the alloy, considering the longer heat treatment time and lowering of the flexural strength, it is thought that the precipitation of Co3WCX phase to make the binder phase disperse and harden is not an effective method for the development of new grades. Another way should be found. .(3) The typical heat treatment of cemented carbide is shown in Table 2.Table 2 typical heat treatment process of hard alloyFigure 4 The properties of WC cemented carbide vary with the amount of Co and grain sizeFig. 5 Relationship between hardness and aging time of WC-Co alloy binder phaseFig. 6 Relationship between hardness and aging time of WC-Co alloy4. Hard alloy coatingIn order to further improve the wear resistance of the hard alloy, a hard material such as TiC or TiN may be vapor-deposited on the surface thereof. The coating material should meet the following requirements:1 It should have high hardness at low temperature and high temperature.2 has good chemical stability.3 should have permeability and no air hole.4 The material to be processed should have a low friction factor.5 To bond firmly with the tool body. 6 It is economical and easy to produce. In today’s world, cemented carbide is also the main material of cutting tools. It is also expanding its application share in molds, measuring tools and other fields.To sum up, it is mainly used in the following aspects:1 Turning in continuous cutting.2 Profiling turning with little change in knife depth.3 require intermittent vehicles with low intensity.4 High-speed face milling of steel or gray cast iron.The advantages of coated cemented carbide are many and summarized as follows:1 Good versatility.2 can improve the accuracy of the workpiece cutting surface.3 The cutting speed is greatly increased at the same tool life.4 At the same cutting speed, tool life can be increased.(1) Coating material Most foreign manufacturers use TiC coating for coated inserts, followed by TiN coating. TiC-TiN composite coating and Ti (C ? N) solid solution coating gradually increased. In recent years, many new composite coatings have also been developed.TiC is currently an ideal coating material, its advantages are high temperature hardness, high strength, good oxidation resistance and crater wear resistance; its disadvantage is that the coefficient of thermal expansion and the body is larger, and the side wear resistance is poor. Compared with the TiC coating, the TiN coating has the following advantages: the coated blade has a low tendency to form a crater when cutting, and its coefficient of thermal expansion is close to that of the substrate, and has a low sensitivity to thermal shock and is not likely to form a tumor. Anti-side wear is good, and it is easy to deposit and control. The disadvantage is that the adhesion to the substrate is less solid. TiC-TiN composite coating and Ti(C?N) solid solution coating are new coatings developed in the 1970s and have been successfully applied in production.The composite coating hard coating has a promising future.(2) Coating process The process and equipment for producing TiC coating inserts at home and abroad are similar. The common feature is that the treated cemented carbide inserts are placed in a deposition reaction chamber, and then H2 is used as a carrier to introduce TiCl4 and methane into the reaction chamber. Deposition reaction. The reaction temperature is roughly controlled at about 1000°C. The heating method is almost always the same high-frequency induction heating, and the deposition pressure is mostly negative pressure. Although a good quality coating can be deposited under normal pressure, the use of negative pressure deposition is more efficient and the coating is more uniform and dense. Especially when the number of deposition blades is large, the advantages of using negative pressure deposition are particularly significant.(3) Coating thickness The thickness of the TiC coating is usually 5~8μm for coating inserts produced at home and abroad. The thickness of TiN coating is in the range of 8~12μm. (4) The coating matrix coating performance is greatly affected by the matrix composition, the coated blade matrix should meet the following requirements: 1 has good toughness and resistance to plastic deformation. 2 has a high hardness. 3 Its chemical composition must match the coating material, and the mutual adhesion should be firm. 4 is not damaged at high deposition temperatures. 5 The coefficient of expansion is similar to that of the coating material. 6 has good thermal conductivity. When machining steel materials, WiC-TC-Co or WC-TiC-TaC-Co alloys should be selected; when machining cast iron or non-ferrous metals, WC-Co alloys should be selected. Different processing materials, the requirements of the coating alloy matrix is also different, meaning that the coating should also be personalized, any heat treatment process is not a panacea, as long as under the specific conditions to maximize their effectiveness.5. Application of Cemented Carbide in Tool and Die Production(1) In the field of cutting tools, cemented carbide maintains excellent cutting performance even at high temperatures of 800-1000°C. It is suitable for rapid cutting at high temperatures and has practical significance for improving economic efficiency. Therefore, it is gradually replacing high-speed tool steels. Make tools. In 2017, it has been widely used not only in lathes, planers, boring knives, three-blade cutters, die cutters, and end mills, but also with the continuous promotion of smart manufacturing and industrial 4.0. Broader, looking forward to the future Tool material is undoubtedly the world of hard alloys.(2) In the field of molds, various types of wire drawing die and wire drawing die are basically made of cemented carbide. The progressive die for making zipper teeth uses YG8 and YG15 hard alloys to make large-diameter drawing dies and YG20C hard dies. Alloys for multi-position progressive die. Non-magnetic mode is generally made of YG15 and YG20 cemented carbide. The service life of YG8 nitrogen ion implanted wire drawing die is more than doubled. In short, the application of cemented carbide in molds is becoming more and more common. It is also used in the gage and other tool industries and will not be described in detail.6. ConclusionAfter the appropriate heat treatment of the hard alloy, although it can improve a little hardness, but taking into account the longer heat treatment time and detrimental to the bending strength, so heat treatment should have a certain degree of specificity. The surface coating strengthens the new path for the use of cemented carbide, and the coating substrate, material, process, and thickness should also be individualized.
Source: Meeyou Carbide

Posted by: jasonagnes at 04:06 AM | No Comments | Add Comment
Post contains 2089 words, total size 13 kb.

Some CNC milling cutters that CNC machining must master, such as round nose knives, ball knives, etc.

 1. Introduction of the tool

CNC machining tools must adapt to the high speed, high efficiency and high degree of automation of CNC machine tools. CNC milling cutters are mainly divided into flat-bottomed knives (end mills), round nose knives and ball knives, as shown in Figure 1-1. They are divided into white steel knives, flying knives and alloy knives. In the actual processing of the factory, the most commonly used knives are D63R8, D50R6, D35R5, D35R0.8, D30R5, D25R5, D20R4, D20R0.8, D16R0.8, D12, D10, D8, D6, D4, D3, D2. , D2, D1.5, D1, D0.5, D10R0.5, D8R0.5, D6R0.5, D4R0.5, R5, R4, R3, R2.5, R2, R1.5, R1 and R0.5 .

Figure 1-1 CNC milling cutter

(1) Flat bottom knife: mainly used for roughing, plane finishing, shape finishing and clear angle processing. The disadvantage is that the tip is easy to wear and affects the machining accuracy.

(2) Round nose knife: It is mainly used for roughing, plane finishing and side finishing of mold blanks, especially suitable for roughing of molds with high hardness.

(3) Ball knives: mainly used for non-planar semi-finishing and finishing.

2. Tool use

In CNC machining, the choice of tool is directly related to the processing accuracy, the quality of the machined surface and the processing efficiency. Choosing the right tool and setting reasonable cutting parameters will enable CNC machining to achieve the best machining quality at the lowest cost and in the shortest time. In short, the general principle of tool selection is: easy installation and adjustment, good rigidity, durability and high precision. Under the premise of meeting the processing requirements, try to choose a shorter tool holder to improve the rigidity of the tool processing.

When selecting a tool, the size of the tool should be adapted to the size of the blank. If the size of the cavity is 80×80, the tool such as D25R5 or D16R0.8 should be selected for roughing; if the size of the cavity is larger than 100×100, the D30R5 or D35R5 flying knife should be selected for opening; if the cavity The size is larger than 300 × 300, then you should choose a flying knife with a diameter larger than D35R5 for roughing, such as D50R6 or D63R8. In addition, the choice of tool is determined by the power of the machine. For example, a CNC milling machine or machining center with a small power cannot use a tool larger than D50R6.

In the actual machining, the end mill, the boss, the groove, etc. of the contour of the plane part are often selected by the end mill; the surface, the side surface and the cavity of the rough machining of the milling cutter with the cemented carbide insert are selected; the ball end milling cutter is selected. The round nose knife has an angled contour shape.

3. Tool cutting parameter setting

The principle of reasonable selection of cutting amount is: when roughing, it is generally to improve production efficiency, but economical and processing cost should also be considered; in semi-finishing and finishing, under the premise of ensuring gun drilling inserts processing quality, taking into account cutting efficiency , economy and processing costs. The specific values should be based on the machine manual, the cutting amount manual, and the experience.

With the wide application of CNC machine tools in production practice, CNC programming has become one of the key issues in CNC machining. In the process of programming the NC program, it is necessary to select the tool and determine the amount of cutting in the human-computer interaction state. Therefore, the programmer must be familiar with the selection method of the tool and the principle of determining the amount of cutting, so as to ensure the processing quality and processing efficiency of the part, give full play to the advantages of the CNC machine tool, and improve the economic efficiency and production level of the deep hole drilling inserts enterprise.

Table 1-1 and Table 1-2 list the parameter settings of the flying knife and the alloy knife respectively. These cutting parameters are for reference only. The actual cutting amount should be determined according to the specific machine performance, part shape and material, clamping condition, etc. Make adjustments).

The larger the diameter of the tool, the slower the speed; for the same type of tool, the longer the tool bar, the smaller the knife size will be, otherwise it will be easy to slash and cause overcutting.

Table 1-1 Flying knife parameter settings

The above flying knife parameters can only be used as a reference, because the parameters of different flying knife materials are also different, and the length of the flying knife produced by different tool factories is slightly different. In addition, the parameter values of the tool are also different depending on the performance of the CNC milling machine or the machining center and the material to be machined. Therefore, the parameters of the tool must be set according to the actual conditions of the factory. The flying knife has good rigidity and a large amount of knife, which is most suitable for the opening of the mold blank. In addition, the quality of the sharp surface of the flying knife is also very good. The flying knife is mainly made of knives and has no side edges. As shown below
                                                              

                

Table 1-2 Alloy knife parameter settings

The alloy knife has good rigidity and is not easy to produce a knives. It is the best for finishing the mold. The alloy knives have the same side edge as the white steel knives. The side edges are often used when finishing the copper straight wall.

Posted by: jasonagnes at 05:53 AM | No Comments | Add Comment
Post contains 1182 words, total size 11 kb.

How to choose a suitable end milling cutter in processing?
A. Classification by Material
1. White steel milling cutter: also known as high-speed steel, it has soft and hard properties. High speed steel cutting tools are cheap and have good toughness, but their strength is not high, making them easy to cut. Their wear resistance and thermal hardness are relatively poor. The hardness is approximately 600 degrees. When using white steel to mill harder materials, if the coolant is not in place, it is easy to burn the tool. This is one of the reasons for the low thermal hardness.
2. Hard alloy milling cutter: Hard alloy (tungsten steel) has a series of excellent properties such as good thermal hardness, wear resistance, good strength and toughness, heat resistance and corrosion resistance. Especially, even at 500 degrees, the high hardness and wear resistance remain basically unchanged, and still have high hardness at 1000 degrees.
3. Ceramic milling cutter: also known as oxidation milling cutter, it has extremely high hardness, heat resistance up to 1200 degrees, compressive strength is extremely high, but brittleness is too high, so the strength is not high, so the cutting amount cannot be too large. Therefore, it is more suitable for final precision machining or other high wear resistant non-metallic processing products.
4. Superhard material milling cutter: it has enough toughness whether it has excellent hardness, wear resistance or heat resistance. Its temperature can withstand up to 2000 degrees because it is too brittle and not solid. More suitable for final finishing.
B. Classification according to the manufacturing method of end mills
1. Grinding blade: This type of blade has better dimensional accuracy, so the positioning accuracy of the cutting edge in milling is higher, which can achieve better machining accuracy and surface roughness. Grinding Inserts with large front corners can be used for milling viscous materials TCGT Insert such as stainless steel. Through the shearing effect of sharp Inserts, the friction between the blade and the workpiece material is reduced, and the chips can leave the front of the blade faster.
2. Pressing blade: It is best to choose a pressing blade for rough machining, which can reduce processing costs. The dimensional accuracy and sharpness of the pressed blade are worse than those of the ground blade, but the edge strength of the pressed blade is better. It has impact resistance and can withstand greater cutting depth and feed.
3. Combination blade: Install the pressed blade in the blade seat of most milling cutters, and then configure the polishing scraper blade to remove rough machining marks.

D. According to the cutting edge of the milling cutter
1. Flat bottom milling cutter: Machining Carbide Inserts also known as end milling cutter, smooth cutter, gong cutter, and purple cutter. They are usually used for precision machining, semi precision machining, precision machining, and milling cutter Inserts for machining flat surfaces, side planes, grooves, and mutually perpendicular step surfaces. The more numbers, the better the effect after completion.
2. Rough milling cutter: also known as wave edge cutter, used for rough machining of workpiece surfaces. According to the tooth profile of the wave edge, it is divided into coarse teeth, medium teeth, and fine teeth. Different tooth shapes result in different machining parameters. Generally speaking, this type of milling cutter allows for a large cutting amount, so roughening of the workpiece is the preferred choice.
3. Ball end milling cutter: Due to the spherical shape of the blade, it is called a ball end milling cutter, also known as a computer ball cutter or R milling cutter. It is usually used for semi precision machining and precision machining of various curved surfaces and curved grooves.
4. Round nose milling cutter: also known as cow nose milling cutter or rounded milling cutter. It is commonly used for processing right angle step surfaces or grooves with R angles, and is often used for semi precision and precision machining.
5. Copper aluminum milling cutter: mainly manufactured for the characteristics of copper aluminum materials. Its characteristics are large front corner, large rear corner (sharp teeth), large helix, and good chip removal effect. It is processed from copper and aluminum. Preferred.
6. T-groove milling cutter: mainly used for processing T-groove and side groove.
7. Chamfer milling cutter: mainly used for chamfering the inner holes and shape of molds. The chamfers are 60 degrees, 90 degrees, and 120 degrees.
8. Internal R milling cutter: also known as concave end milling cutter or reverse R ball cutter, commonly used as a specialized milling cutter for milling convex R-shaped surfaces.
9. Countersunk milling cutter: mainly used for processing hexagonal socket screws, mold thimbles, and mold nozzle counterbore holes.
10. Oblique cutter: also known as conical cutter, it is commonly used for ordinary blade processing, draft allowance processing, and conical surface processing after concave surface processing. The slope of the tool is the degree on one side.
11. Swallowtail groove milling cutter: Shaped like a dovetail, mainly used for machining dovetail groove contour workpieces.

As the core enterprise in the China Minmetal Group，ZCC·CT has 741 million Yuan of the registered capital and more than 1800 employees. ZCC·CT also holds two wholly-owned sales subsidiaries in the U.S. and Germany. The combination of production、development、and sales brought ZCC·CT at the leading position of the cemented carbide cutting tools as an integrated supplier. Meanwhile, ZCC·CT built up the world class production lines of indexable CNC inserts、indexable cutting tools、solid carbide drilling tool、and ceramics inserts. However, ZCC·CT is more than a manufacturer, but also a national innovative-oriental high-tech enterprise. The R&D personnel of ZCC·CT accounts for more than 25% of the total number of employees. It creates a research and development centre which is the core components of the Key State Laboratory of cemented carbide.

Zhuzhou Cemented Carbide Cutting Tools Co., Ltd

Tel: +86-731-22887457

Fax: +86-731-22889023

Zhai Lili: +86-731-22887833

E-mail: globe@zccct.com

Add: Huanghe South Road, Tianyuan zone, Zhuzhou, Hunan, China

Posted by: jasonagnes at 07:52 AM | No Comments | Add Comment
Post contains 1001 words, total size 7 kb.

Global leader in metal cutting, Sandvik Coromant, has earned the 2022 IndustryWeek Best Plants Award for its Westminster, South Carolina, production site. The award is given to North American manufacturing plants that lead their industries in outstanding operational excellence, customer service and employee engagement.

IndustryWeek’s (IW) evaluation and selection process for the award includes an in-depth questionnaire and supporting statement that details candidate achievements. Selected by a panel of IW Shoulder Milling Inserts editors and outside experts, participants are judged on practice and performance factors such as performance measurement, management practices, employee empowerment, customer focus, manufacturing operations, flexibility and environmental and safety programs.

For over 20 years, Sandvik Coromant has continuously improved its  Westminster facility and empowered its people. The company has reportedly invested over $200 million in the production center, which has positioned Sandvik Coromant to serve its customers’ metalworking and machining application needs and provide customer support when needed. According to the company, the 328,000-square-foot production unit reconditions solid round cutting tools and manufactures more than 2,300 standard article and customized cemented carbide inserts, as well as more than 50 grades BTA deep hole drilling inserts of ready-to-press powder and press tools.

The factory, which primarily serves the automotive and aerospace industries, features high automation and advanced technologies. As part of its Green Factory initiatives, the facility and its production equipment have undergone digital transformation to better meet its 2030 energy reduction goals. Renewable energy credits will power its total electricity consumption through 2024, supporting its goal to halve its carbon emissions, while efforts such as ethanol recycling contribute to its goal of greater than 90% waste circularity. The company has also reportedly recycled 245 tons in 2019 and 219 tons in 2020.

Sandvik Coromant’s Westminster site is also said to invest in the continuous improvement of its people. All employees have a learning and development plan, and the company offers ongoing learning opportunities. A mature safety program ensures employees know how to work as safely as possible, and personnel are encouraged to report unsafe conditions into a global database so the conditions may be corrected and preventive actions implemented. The company says its strong safety cultures contributes to industry-leading results in regard to OSHA recordables and lost-time injuries.

Posted by: jasonagnes at 06:39 AM | No Comments | Add Comment
Post contains 384 words, total size 3 kb.

Posted by: jasonagnes at 04:03 AM | No Comments | Add Comment
Post contains 6 words, total size 1 kb.