Modern technological solutions for the chemical-thermal treatment

Many experts on the heat treatment will agree with the fact that the equipment for chemical-thermal treatment is much older than the equipment in the sections of the blade processing. Common practice shows that the main tools in modern enterprises spent on modernization and purchase of new machinery for mechanical treatment, and scarce funds remain in the maintenance of existing thermal equipment.

HTO

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Milling machine CNC for tool production

The task was to run and help with the implementation of a router CNC in tool production. The choice of milling machine with CNC was pretty good.
General view of milling machine


I for the last 4 years have not seen a milling machine with CNC, which was better suited for work in the tool shop than DNN400а manufactured by DOOSAN.

the Main advantages of this milling CNC machine for the tool proizvodstva

1 Milling operation in tool production associated with the use of a huge number of cutting tools, the use of kulachkova mechanism, this milling machine CNC allowed to reach of tool change time of 1.3 s, which is not bad.

Change tool

2 the Eternal problem with the cleaning of the small chips obtained when machining large parts not solved quite simply — compressed air is supplied.

3 High speed milling machine with CNC, passport 40m/min (not measured with a stopwatch), which is enough.

4 Drop in the working area temperature for 5 days was 0.3 degrees, which I really liked, i.e. tuned and working without interruption. There is no need to worry that the size of the float.

5 Milling CNC machine gives high accuracy of processing:

Deviation from the roundness of 5.4 µm when machining end mill holes with a diameter of 16 mm in aluminum alloy milling CNC machine

the roundness of a surface

Roughness of machined surface of aluminium with a speed of 8000 rpm, a feed rate of 1000 mm/min is not more than 0.12 µm

the Roughness of the resulting surface

6 Increased rigidity of the frame and rack milling machine with CNC (frame and a monolithic reinforced ribs), which allowed me to handle on it dies and molds. Stand securely supports the table at any point of the stroke without hanging the console.

the Rigidity of the frame for milling CNC machine

All 7 axis milling CNC machine is equipped with rigid precision linear guides

8 High speed spindle: 20,000 rpm

9 Expansion Y-axis reduced by approximately 30% due to the withdrawal of air from the belt drive by using a standard fan

10 most milling CNC machine liked that it is equipped with a cooling system of coolant.

11 device for the automatic measurement of the items received, without removing details (without it you can work not present)

Measurement received

In my Opinion these are the most important parameters by which you want to choose a modern milling CNC machine for high production

In General machine I liked

Coatings of hard alloys for cutting tools

the processing of metals has shown that one effective way of increasing performance is the use of new tool materials.

coated Tool


the Coating of the cutting tool must increase:

hardness, in order for a long time to save cutting properties of the tool;

— ability to maintain necessary hardness when cutting Mella;

— tool.

Cover can be the tool of any geometrical complexity

currently, approximately 75% of the world’s cutting tool made of hard alloy.

Qualitatively new stage of production of cutting tools associated with the opening at the end of the last century, technologies of ion-plasma wear-resistant coatings. In the world of technology for hardening is represented by two methods: chemical vapor deposition method (Chemical Vapour Deposition — CVD) method and physical vapor deposition coatings (Physical Vapour Deposition — PVD). In Russia, the widespread industrial application has received PVD-methods of applying protective coatings on cutting tools. This is because CVD technology involve the use of expensive high-purity chemical reagents (TiCl4, NH3, etc.) and precise control of the products of chemical reactions in the chamber. And the application of PVD coatings using arc or glow discharge (magnetron) has a better performance and not so sensitive to slight deviations of technological parameters.

The Variety of currently used methods of physical vapour deposition of wear-resistant coatings is reduced to evaporation or ion sputtering of titanium or its alloys, the ionization and heterogeneous reaction on the surface of the tool atoms and metal ions and the reaction gas, leading to the formation of a nitride, carbide, carbonitride.

coated Tool can be found in any industry

Structure and the adhesion of the coating tool and their cutting properties defines many parameters: increasing the degree of ionization, velocity, and flux density of the sprayed particles, optimization of the temperature of the coating, the use of ionic cleaning of the substrate, the accelerating voltage, Rvarious industry modes of application, the configuration tooling, conducting advanced tive ion etching or doping, and many others features determine the structure of the coatings and formationtion of the interface «coating — substrate».

In the early 80s of the last century started to be applied and immediately showed the economic efficiency of TiN coating. The next step was the creation of two-layer coatings consisting of successively deposited layers of titanium carbide TiC or titanium carbonitride TiCN and a thin surface layer of aluminum oxide Al2O3.

The Alternative served as a multi-coating type TiCTiCNTiN. It should be noted that the concept of «layered» in many cases, very arbitrary, since the methods of spraying can achieve the absence of distinct phase boundaries between the layers and between the coating and the substrate. Multilayer hard wear resistant coatings have a high crack resistance, improved adhesion, high impact strength, a lower level of internal stresses and strains on the boundary «coating — substrate» due to the alignment of coefficients of thermal expansion. For example, the TiCN coating has a layered two-phase structure of TiN–TiCN that increases the strength and viscosity characteristics compared to TiN coating.

Coated cutting tool point method

In the last decade developed and widely usedare different combinations of coatings with the use of a thin external hard lubricant coatings (such as TiAlN/MoS2) provide good chip removal. Low coefficient of friction and high wear resistance.ut very hard diamond-like coatings (diamondlikecarbon coatings — DLC). However, they have a serious wealth: very high level of internal stress, leading to embrittlement and flaking at high constroke stress which limits the thickness ofwell, coatings up to 1 ám. Another problem of such coatings — low thermal conductivity, which can lead to them local graphitization with subsequent leaching. Toptions operating temperature limit is restricted to 250 °C, and treit is necessary to use lubricating coolants (GM). Coating cubic boron nitride (CBN) aboutladyt high level of internal stresses and the thickness of the coating is not more than 0.1 microns.

In the face of competition companies are forced to constantly improve their processes in the area of reducing the complexity, improving the quality and efficiency of the equipment.

During the cutting process, the maximum efficiency is achieved when the integrated use of high-tech equipment, equipped with CNC machining and modern metal cutting tool, providing greater cutting speed and performance.

Most versatile group of cutting materials, allowing the to complete the processing of the vast majority of metal non-metallic materials. Carbide tools are designed for cutting speeds up to 300 m/min (drill 50-70 m/min, cutting-edge developments to 90-180 m/min); used, in bulk, on machine manufacturers with spindle speed average up to 10,000 rpm To improve the properties (increase of hardness, decrease of the radius of curvature of the cutting edge and, consequently, to increase the resistance of the tool) manufacturers are committed to reducing the grain of alloys.

Manufacturers offer a wide range of designs, geometries processing of all metallic materials. From foreign suppliers in Russia work: Sandvik Coromant, Iskar, Wolf, Seco, Mitsubishi, Walter, Korloy, Kennametal, Dormer.

Among Russian producers note of LLC «SKIF – M» (Belgorod) — developer and manufacturer of milling cutters with interchangeable cutting plates of hard alloy and JSC «Serpukhov tool plant «Twintos». Plant «Twintos» also undertook the original development of designs of cutters, software, and manufactures milling method visitvirginia of carbide blanks manufacturers.

Setting spray

One of the drawbacks of almost all the vendors listed above is the lack of services for regrinding solid carbide milling cutters and carbide recycling plates and working parts of the cutters. It should also be noted that all of these providers focused primarily on the sale of the tool for the new, modern equipment, and the selection of carbide tools with SMP for the equipment of domestic production being extremely reluctant.

For dry processing of well-established TiAlN coating. This coating allows to improve adhesion, increase impact strength, reduce the coefficient of friction, have high tremendoustomato.

At the same time, the coating increases the radius of curvature of the cutting edges that have adverse impacts, for example, when removing a small allowance.

Comparative table of coating a cutting tool

Some coatings are characterized by high internal stresses leading to delamination of the coatings. The most applicable coating on the profile tools and inserts, as when regrinding coating on parts subjected to grinding, completely destroyed.

In Russia, the coating is OOO «Technological coverage» (Moscow), NPF «Elan Practitioner»(Nizhny Novgorod).

the Main types of PVD coatings (characterized by a thickness of 1-3. 5 µm, therefore, applied to cutting edges with a small radius to reduce cutting forces, improve breaking, prevent vibration) and CVD coatings with a thickness up to 20 µm (Al2O3). The main difference between these coatings is the method of application: PVD coating (400–500oC) used physical vapour deposition, CVD (1000–1100оС) chemical.

Shock mechanical destruction of the tool also adversely affects the coatings, and therefore their effectiveness may be reduced when using imperfect equipment.

In addition to wear-resistant coatings (the most common nitride TiAlN, TiAlCrN, TiN) have been used hard lubricant coating having a very low coefficient of friction and reducing the cutting forces and the chip evacuation (TiO2, WO3V2O5).

Tool with brazed carbide inserts or replaceable carbide knives for end mills, the most spoken in Russia. Its advantages: simplicity, low cost. The main drawback is its low performance, the need for high-quality sharpening. The cutting speed rarely exceeds 100 m/min

the Tool with coating and without it

Solid CVD-coated grade

the Reliable contact of the coating with high strength.
the Obstacle is the formation of build-up and high wear resistance.
the Optimal choice for roughing of stainless steels
High performance in low carbon and structural steels.
High durability when machining hard materials.

Hard alloys without coating

Hard alloy tool materials are obtained by powder metallurgy which are based on tungsten carbide, titanium, tantalum with the use of cobalt binder (TaC, TiC and WC). Vacuum sintering improves physical characteristics (strength, wear resistance, heat resistance, etc.) of the materials and extends their field of application.
the benefits of a Wide range of manufactured brands of alloy for the groups R,M,K the Resistance to the formation of thermoresin.VOZMOZhNOSTI manufacturing SMEs with a high degree of accuracy of the geometric dimensions.

Hard alloys coated РVD

High efficiency machining of cast irons, carbon, stainless and heat resisting steels.
fine-Grained structure has high hardness and toughness, which prevents spalling and enhances durability of the cutting edge.
Advanced technology РVD coating provides high hardness and prevents oxidative deterioration at high temperatures.

Solid alloy coated РVD

the

Ultra-fine grained cemented carbide

Ultra-fine grain hard alloy has higher mechanical strength in comparison with hard alloy having an average grain size. This allows significantly increase cutting speed.

Ultra-fine grained cemented carbide

the

Hard alloys diamond-coated

Increases tool life by 150%.
Reduced coefficient of friction between the chip and the front surface of the SMP coating (~ 10 microns) reduces the heating plates.
Reduced built-up edge
improves the quality of the treated surface.

Solid alloy plated with diamond

the

Hard alloys with DLC coating

Low friction coefficient on the front surface (<0,1) provides high-quality processing.
ensuring a high resistance when machining non-ferrous metals can be Applied to process aluminum, plastic, wood Coating used for turning SMP, drills and end mills.

Hard alloys with DLC coating

the

Polycrystalline diamond (PCD)

Plastiny of PKA (polycrystalline artificial diamond) sintered at high temperature on the basis of the medium and small diamond crystals and have a high hardness and wear resistance.
materials:
Aluminum and copper alloys
Aluminum alloy with high silicon content
plastic materials

Drilling deep hole

will Try in detail to explain the essence of the process of deep drilling.

Drill for deep hole drilling


 

Defekty deep hole drilling:

the tilt of the axis of the hole at the ends of the billet;

the curvature of the hole axis in cross-sections of billet;

raznoshennoy of the workpiece in cross-section;

ledges of holes at the interface for two-sided drilling;

kink axle, drilled from two sides of the hole;

ellipticity (out-of-round) holes.

These defects obtained during deep drilling, in addition to ellipticity, associated with the withdrawal of the drill from the desired direction. Under the disposal of the axis of the hollow cross-section or at the ends of the workpiece after drilling refers to the deviation of the axis of the hole from the axis of the holes outlined in the drawing.

 the Defects obtained during deep drilling and properly drilled hole (without withdrawal); b — drift is in the plane X—K; b — the pull is located between the planes X—Ki X—Z; g — the curvature of the axis of the hole caused by the slip; d is the curvature of the axis of the hole, caused by warping; e — ledge-bilateral drilling, fracture to the bore axis from bilateral drilling; z — taper; and — bochkoobraznoj holes

curvature Correction of the hole in deep drilling is carried out either by pressure or by boring to the depth of the hole.

Corrigendum of raznoshennoy when deep drilling received from the disposal of drill, carry out external machining of the workpiece. The centering of the workpiece thus produced from the hole.

curvature Correction to the bore axis should make a edit of the workpiece or the boring of a hole, permitting the allowance.

If the withdrawal for two-sided drilling is developing in relation to the workpiece in one direction, there will be a fracture to the bore axis, if in the opposite direction — you get the ledge.

Both of these defect very unpleasant when deep drilling and can be fixed only by boring. In some cases, multiple, requiring the increased allowance.

the Ellipticity of the holes caused by the phenomenon of «copying» when boring holes with uneven. To eliminate the ellipticity can be, if you allow the seam allowance, finishing or rough boring. Sometimes ellipticity eliminate pulling.

defects in the cut, are vibrating then formed on the surface of the hole of the workpiece due to the vibrations of the drill.

Taper holes when drilling occurs because of the increased wear basic guides drills, or their bearing edges. So if you have taper special attention should be paid to the material of the cutting and guide elements of drills and coolant. It is noticed that instruments with external chip removal tend to form a greater taper than the tools with internal chip removal.

Bochkoobraznoj holes occurs only if the drill is losing support in the hole and quickly fails.

the Average drift of the axis of the holes for drilling odnocletocnami drills was 1.5 mm, while the average slip when drilling choose from double-lip drills was 4.5 mm, ie was three times higher than odnokletochnykh drills.

experiments were conducted with drill, covering virtually every possible combination of drills: drills with absolute certainty-based (odnokratnye drill) to drill without certainty-based (twin-edge drill, the working methods of dividing flow). Wanting to test the specificity of certain types of tools in respect of cutting speed, drilling was conducted at high and low speeds.

cutting Speed, no matter what size she may be, is not the cause of the withdrawal of the drill, however, this factor can reduce cross raznoobrazhivaet and significantly reduce the drift.

When drilling with the rotation of the workpiece the angle between the axis of rotation of the workpiece and the axis of the drill and has an effect on withdrawal, but much less than with a stationary workpiece. This mismatch can be corrected easily when drilling rotating workpiece.

currently, the permissible slip of the drill for deep hole shall be taken as 0.3 mm per 1 m length of drilling.

For drilling with small withdrawals, you need the following:

1) to run at high speeds;

2) used as workpiece materials for possible high-alloy, fine steel prokalyvayutsya;

3) conduct operations thoroughly heat treatment of the blanks before drilling, preventing large lateral raznoobrazhivaet;

4) to make drilling possible with the rotation of the workpieces;

5) use a more rigid drill;

6) external pre-drilling of workpieces such as bodies of rotation to provide uniform allowance to eat;

7) to accurately center the blanks and fill the holes under the length of the tool.

Desktop milling machine CNC

let me Remind You that a desktop milling machine with CNC is a reduced copy of a large machine, and in principle, it performs the same function and has an identical design. Desktop milling machines CNC have a size of less 910х880х880. Thanks to its compactness, these milling machines can be installed in a domestic environment, for example at the cottage, garage or even in the shop for the production and sale of Souvenirs.

table milling machine

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