How to check the quality of blade welding

How to check the quality of blade welding?

In order to ensure the welding quality, the turning tool after welding shall be carefully inspected to find out the causes of defects and improve them. Before inspection, the turning tool shall be sandblasted or lightly ground to remove the solder and impurities adhering to the blade surface, and cleaned with kerosene. The inspection items and requirements are as follows:

1、 Check the weld strength: grind the back of a turning tool with a green silicon carbide grinding wheel, and check the thickness of the solder layer, which is required to be less than 0.15 mm. There shall be no air hole or insufficient solder at the bottom surface of the tool tip support, and the weld not filled with solder shall not be greater than 10% of the total weld length. If there are air holes, the blade will fall off during cutting.

2、 Check the position of the blade in the tool groove: if the blade is misaligned and sagged beyond the technical requirements, re weld it.

3、 Check the welding strength: use a wooden hammer or a copper hammer to knock the blade with medium force, or use a hammer I to knock the cutter bar with strong force. If the blade does not fall off from the cutter groove, it RCGT Insert is qualified. Check the welding strength of the blade, not necessarily one by one, but also by sampling.

4、 Check the flatness of the blade: if there are obvious pits on the blade, it indicates that the blade is overheated and deformed, and the new blade should be burned and re welded.

5、 Check for cracks: after the blade is cleaned with kerosene, if the blade has cracks, kerosene will penetrate into the cracks and black lines will appear, which can be observed with the naked eye. It can also be observed with a 10-40x magnifying glass.

To check blade cracks, color flaw detection method can also be used: a solution made of 65% kerosene, 30% transformer oil and 5% turpentine, with a little Sudan red added. Put the part of the turning tool blade in the solution for 10-15 minutes, wash it with clean water, apply VBMT Insert a layer of white clay (kaolin), bake it for 1000 minutes, and observe its surface. If there are cracks on the blade, the color of the solution will be exposed on the white clay, which can be seen with the naked eye. The cracked blade cannot be used and needs to be re welded.

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When to Use Wet Milling or Dry Milling？

Milling process is essentially a kind of intermittent processing process. This causes the temperature at the cutting edge to fluctuate between high temperature (about 1000 ℃) and low temperature.

Contents hide 1Effect of cutting fluid 2dry milling 3wet milling with cutting fluidEffect of cutting fluid

When the cutting edge cuts in and cuts out, the temperature change will increase. Cutting Tool Carbide Inserts As a result, the cutting edge is subject to thermal shock and periodic stresses, which may result in cracks and, in the worst case, premature end of tool life.

The higher the temperature of the cutting area, the less suitable the cutting fluid is.

In the finishing process, the use of cutting fluid will not shorten the tool life as much as in rough machining due to the reduced heat generated.

Hot cracks on cutting edgedry milling

Dry milling can prolong the life of cutting edge. The temperature does change, but it will remain within the design range of cemented carbide materials.

Rough milling should always be carried out without cutting fluid.

wet milling with cutting fluid

There are some exceptions to the use of cutting fluid:

1) Finish machining of stainless steel and aluminum alloys – used Carbide Drilling Inserts to prevent metal particles from sticking to the surface structure

2) Milling superalloys at low cutting speeds – for lubrication and cooling of parts

3) Cast iron milling, used to wet and remove dust to protect the environment and health and ensure the accuracy of parts

4) Milling of thin wall parts to prevent geometric deformation

5) When machining deep cavity, micro lubrication system (i.e. compressed air containing a small amount of special oil) can be used to assist chip removal

Use compressed air and oil mist

In the micro lubrication system, the “oil mist” is only a few milliliters of oil per hour, and is discharged through the ordinary filtering ventilation system.

Use a large flow of internal and external coolant

If wet milling must be carried out, a sufficient amount of cutting fluid should be used.

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4 Common Metal Surface treatments to Date

Contents hide 1The Concept of Metal Surface Treatment 2Classification of Metal Surface Treatment Technologies 3Common Metal Surface Treatments 3.1Metal Surface Modification 3.2Metal Surface Hardening 3.3Metal Surface Sandblasting 3.4Metal Surface Rolling 3.5Wire Drawing of Metal Surface 3.6Metal Surface Laser Strengthening 4Metal Surface VCMT Insert Alloying Technology 4.1Blackening and Phosphating of Steel Metal Surface 5Metal Surface Coating Technology 5.1TiN Coating and TiCN Coating on Metal surfaceThe Concept of Metal Surface Treatment

It refers to the process of changing the surface condition and properties of parts and optimizing its combination with matrix materials to meet the predetermined performance requirements by using the edge new technologies of modern physical, chemical, metallurgy and heat treatment disciplines.

Classification of Metal Surface Treatment Technologies

1. Surface modification

The surface chemical composition of the material is not affected by changing the surface microstructure and stress state of the material.

2. Surface Alloying Technology

Adding new materials into the matrix to form alloying layer.

3. Surface film technology

Chemical reaction between additive and matrix to form conversion film

4. Surface Coating Technology

Common Metal Surface TreatmentsMetal Surface Modification

Contains the following methods: surface hardening, sandblasting, knurling, wire drawing, polishing, laser surface strengthening

Metal Surface Hardening

It refers to a kind of heat treatment method that austenitizes the surface layer and cools it rapidly without changing the chemical composition of the steel, so as to harden the surface.

Metal Surface Sandblasting

The surface of workpiece is impacted by high-speed sand and iron particles, which is used to improve part mechanical properties and change surface state. This operation can effectively improve mechanical strength, wear resistance, and eliminate residual stress.

Metal Surface Rolling

It is to press the surface of the workpiece with a hard roller at room temperature so that the surface of the workpiece can be hardened by plastic deformation to obtain an accurate and smooth surface.

Wire Drawing of Metal Surface

Under the action of external force, the metal is forced through the die, and the cross-sectional area of the metal is compressed so as to change its shape and size. The method is called wire drawing. Wire drawing can be made into several kinds of threads, such as straight, curly, wave and threaded, according to decorative requirements.

Metal Surface Polishing

Polishing is a finishing method to modify the surface of parts. It can only get smooth surface without improving the processing accuracy. The Ra value of polished surface can reach 1.6-0.008 um.

Metal Surface Laser Strengthening

A focused laser beam is used to heat the workpiece rapidly and then rapidly cool the workpiece to obtain a hardened and strengthened surface. Laser surface strengthening has the advantages of small deformation, easy operation, and local strengthening.

Metal Surface Alloying Technology

By physical methods, the additive material is added into the matrix to form an alloying layer. Common carburizing and nitriding belong to this kind of technology. It makes the metal and the Infiltrator placed in the same sealed chamber, activates the metal surface by vacuum heating, and makes carbon and nitrogen enter the metal matrix in the form of atoms to achieve the purpose of alloying.

Blackening and Phosphating of Steel Metal Surface

Blackening: Black or blue oxide film is produced to insulate the air from corrosion of the workpiece.

Phosphating: An electrochemical metal surface treatment method for protecting the base metal by depositing a clean phosphate insoluble in the water on the surface of the workpiece immersed in phosphating solution.

Both of them do not affect the internal structure of the workpiece. The difference is that blackening of iron and steel will make the workpiece shiny, while phosphating will increase the thickness of the workpiece surface and make the surface dull. Phosphating is more protective than blackening. Blackening is generally more expensive than phosphating in terms of price.

Metal Surface Coating Technology

The layer of coating or coating is formed on the surface of the substrate by physicochemical method. This is widely used in cemented carbide tools.

TiN Coating&WNMG Insert nbsp;and TiCN Coating on Metal surface

A few microns thick TiN material is usually golden on the cutting tool for cutting softer copper or low carbon steel.

Black TiCN coatings are mostly used in occasions with small friction coefficient but high hardness requirements.

Above is our brief introduction of metal surface treatments. If you have more information about this topic, please leave a message below to discuss with us.

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Smooth Technology Is New Concept for CNC

Smooth Technology is the umbrella term Mazak (Florence, Kentucky) is using to describe its new concept for the programming and control of complex, multi-axis machine tools. Smooth Technology is a complete package of control unit, machine hardware and servo systems. All of these components have been engineered to work together for enhanced functionality, speed and ergonomics, the company says. The concept combines part programming, setup, the actual metal removal operations, integrated automation, and monitoring through the collection and transfer of performance data.

The most prominent component of the Smooth Technology package is the new Mazatrol SmoothX CNC. With this CNC, Mazak says that it has quadrupled interpolation speed over CNC Inserts previous-generation controls. This development is said to shorten machining times and enhance such operations as full simultaneous five-axis machining and complex mold machining. New functions of the control include Intelligent Pocket Milling (to maintain a constant angle of tool engagement), Seamless Corner Control (to avoid burying a cutter when entering a 90-degree corner) and Real-Time Tuning (to optimize turret indexing when tool loads are uneven).

On the part programming side, new software functions include Quick Mazatrol, Quick EIA and full five-axis 3D simulation. Neil Desrosiers, applications engineer/developer at Mazak, describes Quick Mazatrol as a hybrid born from the marriage of a CAM system and conversational programming. “Shops are now able to use a solid model to obtain part geometries, but still CCMT Insert program conversationally. This means that with Smooth Technology, users don’t have to know how to use a CAM system to work from a solid CAD model to create programs,” he says.

Quick EIA enables users to rapidly generate any tool path prior to running the program and view it in full simulation. According to Mr. Desrosiers, the secret behind the blazing fast simulation speed of Quick EIA is that the software uses advanced graphics technology—the same type used to generate the graphics for today’s gaming systems. Mazak also has applied these advanced graphics to the five-axis 3D simulation function to check for errors and machine interferences. These extremely realistic and accurate simulations use the same machine movement parameters as actual Mazak model machines.

Another programming function, View Surf, will soon be added to the software. This feature will enable the programmer to analyze and optimize G code faster and more thoroughly by quickly pinpointing the exact line of code that has an error.

At the human-machine interface (HMI) level, the new control features a multi-touch home screen that, within a single page view, presents all critical data to operators. This enables them to jump from the home screen to any other area or section within the CNC. They can use a fingertip to pan, rotate, zoom or otherwise manipulate a 3D rendering of the component being machined. Or they can flick an area of the screen to scroll through the displayed program G code. Navigation is very similar to using a tablet device.

Mazatrol SmoothX CNC consoles are the same size for all machines. In the past, control units were physically larger or smaller, depending on the number of buttons, options and features required for the machine model. The new controls have a common bank of buttons, which makes it easier for operators to go from one Mazak machine to the next.

For digital manufacturing functionality, Smooth Technology supports MTConnect and includes an NC Data Library—an Ethernet interface to a library of data-accessing functions for programmers if they wish to write software to communicate with the machine via an Ethernet network. This also means machines can have an MTConnect adapter and that users can collect data from the CNC. 

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What are carbide milling cutters？

Carbide milling cutters are milling cutters made of cemented carbide. To understand the cemented carbide milling cutter, we must first know what is a hard alloy. The cemented carbide is based on the carbide (WC, TiC) micron powder of high hardness refractory metal, with cobalt (Co) or nickel (Ni). Molybdenum (Mo) is a binder and is a powder metallurgy product sintered in a vacuum furnace or a hydrogen reduction furnace.

Contents hide 1Carbide milling cutter classification 2Carbide milling cutter’s application 3Carbide milling cutter milling method 4Carbide milling cutter’s maintenance 5Carbide milling cutter‘s selectionCarbide milling cutter classification

Carbide milling cutters are mainly divided into: solid carbide milling cutters | carbide straight shank milling cutters | carbide saw blades milling cutters | carbide auger milling cutters | hard alloy machine reamer milling cutters | Carbide end mills | Carbide ball end mills

Carbide milling cutter’s application

Carbide milling cutters are generally used in CNC machining centers and cnc engraving machines. It can also be loaded onto a conventional milling machine to process some hard and uncomplicated heat treatment materials.

1. Carbide cylindrical milling cutter: used for horizontal milling machine processing plane. The teeth are distributed on the circumference of the milling cutter and are divided into straight teeth and spiral teeth according to the tooth shape. According to the number of teeth, there are two kinds of coarse teeth and fine teeth. The spiral tooth coarse-tooth milling cutter has a small number of teeth, high tooth strength and large chip space, which is suitable for rough machining; the fine-tooth milling cutter is suitable for finishing.

2. Carbide face milling cutter: It is used for vertical milling machine, end milling machine or gantry milling machine. It has cutter teeth on the end face and circumference, and also has coarse teeth and fine teeth. The structure has three types: integral type, insert type and indexable type.

3. Carbide end mill: used to machine grooves and step surfaces, etc., the teeth are on the circumference and end faces, and can not be fed in the axial direction during operation. When the end mill has a tooth that passes through the center, it can be fed axially.

4. Carbide three-face milling cutter: used to machine a variety of grooves and step surfaces, with teeth on both sides and circumference.

5. Carbide angle milling cutter: used to mill a groove at a certain angle, there are two kinds of single angle and double angle milling cutter.

6. Carbide saw blade milling cutter: used to machine deep grooves Cemented Carbide Inserts and cut workpieces, with more teeth on the circumference. In order to reduce the friction during milling, there are 15’~1° secondary declinations on both sides of the cutter. In addition, there are keyway milling cutters, dovetail milling cutters, T-slot milling cutters and various forming cutters.

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Carbide milling cutter milling method

The milling direction of the carbide milling cutter relative to the workpiece and the direction of rotation of the milling cutter are mainly the following two milling methods:

The first is down-cutting. The direction of rotation of the milling cutter is the same as the direction of feed of the cutting. At the beginning of the cutting, the milling cutter bites the workpiece and cuts the last chip.

The Cemented Carbide Inserts second type is up-cut milling. The direction of rotation of the milling cutter is opposite to the direction of feed of the cutting. The milling cutter must slide over the workpiece before starting the cutting. The cutting thickness starts at zero and the cutting thickness reaches the end of the cutting. maximum.

When milling, the cutting force presses the workpiece against the table, and the cutting force causes the workpiece to leave the table during up-cut milling. Since the cutting effect of the down-milling is the best, the down-cutting is usually preferred. Only when the machine has a thread gap problem or if there is a problem that can not be solved by the down-milling, the up-cutting is considered.

Each time a cemented carbide milling insert enters the cutting, the cutting edge is subjected to an impact load, which depends on the cross-section of the chip, the material of the workpiece and the type of cutting. Ideally, the diameter of the milling cutter should be larger than the width of the workpiece. The centerline of the milling cutter should always be slightly separated from the centerline of the workpiece. When the tool is placed against the center of the cutting, burrs are easily generated. The direction of the radial cutting force will change continuously as the cutting edge enters and exits the cutting. The machine tool spindle may vibrate and be damaged. The blade may be broken and the machined surface will be rough. The carbide milling cutter will be slightly off center and the cutting force direction will be No longer fluctuating, the cutter will get a preload.

Carbide milling cutter’s maintenance

When the cemented carbide milling cutter axis line and the workpiece edge line coincide or approach the edge line of the workpiece, the situation will be very serious, the operator should do the relevant equipment maintenance work:

1. Check the power and stiffness of the machine to ensure that the required cutter diameter can be used on the machine.

2. The overhang of the tool on the spindle is as short as possible, reducing the influence of the axis of the milling cutter and the position of the workpiece on the impact load.

3. Use the correct milling pitch suitable for this process to ensure that there are not too many blades to engage the workpiece at the same time to cause vibration during cutting. On the other hand, ensure that there are enough blades when milling narrow workpieces or milling cavities. Engages with the workpiece.

4. Make sure that the feed per blade is used to achieve the correct cutting results when the chips are thick enough to reduce tool wear. The indexable insert with positive rake groove shape provides smooth cutting results and lowest power.

5. Use a milling cutter diameter that is appropriate for the width of the workpiece.

6. Use the correct lead angle.

7. Place the milling cutter correctly.

8. Use cutting fluid only when necessary.

9. Follow tool maintenance and repair rules and monitor tool wear.

Proper maintenance of carbide milling cutters can extend tool life and increase work efficiency.

Carbide milling cutter‘s selection

Milling stainless steel except end mills and some end mills and carbide as milling cutter materials, all other types of milling cutters are made of high-speed steel, especially tungsten-molybdenum and high vanadium high-speed steel have good effect, the tool Durability can be 1 to 2 times higher than W18Cr4V. Carbide grades suitable for making stainless steel milling cutters are YG8, YW2, 813, 798, YS2T, YS30, YS25 and the like.

The effect of spray cooling is the most significant, which can increase the durability of the milling cutter by more than one time; if it is cooled by a general 10% emulsion, the cutting fluid flow should be sufficiently cooled. When milling carbide with carbide milling cutter, take Vc=70～150m/min, Vf=37.5～150mm/min, and adjust it according to the alloy grade and workpiece material.

The adhesion and fusion of stainless steel are strong, and the chips are easy to adhere to the cutting edge of the milling cutter, which deteriorates the cutting conditions. When the milling is performed, the cutting edge first slides on the hardened surface, which increases the tendency of work hardening; impact during milling The vibration is large, which makes the milling cutter blade easy to chip and wear.

When milling stainless steel, the cutting edge must be sharp and bear the impact, and the chip pocket should be large. Large helical angle milling cutters (cylindrical milling cutters, end mills) can be used. The screw angle b is increased from 20° to 45° (gn=5°), and the tool durability can be increased by more than 2 times because the milling cutter works at this time. The rake angle g0e increases from 11° to over 27°, and the milling is light. However, the b value should not be large, especially the end mill should be b ≤ 35 °, so as not to weaken the teeth.

The stainless steel pipe or thin-walled parts are processed by the wave edge end mill, the cutting is light, the vibration is small, the chips are brittle, and the workpiece is not deformed. High-speed milling with carbide end mills and milling of stainless steel with indexable end mills have achieved good results.

Milling 1Cr18Ni9Ti with silver end mills with geometric parameters gf=5°, gp=15°, af=15°, ap=5°, kr=55°, k′r=35°, g01=-30° , bg=0.4mm, re=6mm, when Vc=50～90m/min, Vf=630～750mm/min, a′p=2～6mm and the feed amount per tooth reaches 0.4～0.8mm, the milling force is reduced. Smaller 10% to 15%, milling power is reduced by 44%, and efficiency is greatly improved. The principle is that the negative chamfer is ground on the main cutting edge, and the built-up edge is artificially generated during milling, so that it can be cut instead of the cutting edge. The front angle gb of the built-up edge can reach 20~~302, due to the lead angle The effect is that the built-up edge is caused by the thrust generated on the rake face parallel to the cutting edge to become the auxiliary chip, thereby taking away the cutting heat and lowering the cutting temperature.

When milling stainless steel, it should be processed by the same method as possible. The asymmetrical cross-milling method can ensure that the cutting edge is smoothly cut off from the metal, and the contact area of the chip bonding is small, and it is easy to be smashed under the action of high-speed centrifugal force, so that the chip impacts the rake face when the tooth re-cuts into the workpiece. Peeling and chipping improve the durability of the tool.

Stainless steel materials are widely used and can be encountered in machining, milling, drilling and tapping. But because stainless steel has different characteristics than other general materials, processing stainless steel has become a big problem for technicians!

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