superabrasives star in high-speed milling.

by:kingtool aluminium machinery     2020-04-05
High grinding star
A famous lyric is written like this: \"A kiss on your hand may be quite economical, but diamonds are the best friends of girls.
\"If one of your production businesses is processing non-ferrous materials, diamonds,-
Especially polycrystal diamonds (PCD)tooling--
I might be your best friend, too. (
Your best friend is probably a crystal cube bn (PCBN)
Please use tools if you are milling black material).
Ultra-abrasive materials are used high
High temperature-
The stress process of GE development. Compax [R]
Diamond tool blanks are made up of a multi-Crystal Man. Made [R]
As a diamond layer and hard alloy substrate for overall blank production. BZN [R]
Multi-Crystal cubic bn blanks are a combination of [Borazon] LayersR]
CBN and hard alloy substrates.
To make polycrystal diamond into a disk blank (34mm dia).
The disk is cut into different blank shapes and sizes using a wire guide ,.
These blanks are sold to tool manufacturers for the manufacture of a wide variety of finished tools
User metal cutting applications.
Different grades of polycrystal diamond were manufactured.
These are directly related to the diamond crystal size used in the raw material.
For applications that require a good surface finish, it is generally recommended to use finer diamond particles.
Milling applications are usually thicker (
Grain size)grades.
It is usually used to process non-ferrous and non-metallic materials.
Polycrystal diamond is a very hard material, very wear-resistant.
Thanks to its consistent particle structure and the combination of diamond crystals with diamond crystals, it provides a very uniform and consistent wear-resistant cutting edge.
By adding carbohydrates, the totl blanks provide the excellent wear resistance and impedance required for successful milling applications.
The polycrystal cubic bn is also pressed into a disk blank, which is used as a full disk after online EDMing.
A surface insert or a worn-out tip insert.
This material is mainly used for the processing of non-ferrous metal materials such as steel and cast iron.
Observe that Diamond polycrystal diamonds compete with carbide in grinding operations.
Ceramics are trying to bridge the gap between polycrystal diamonds and carbide, but polycrystal diamonds clearly show the advantages of this.
In non-ferrous and non-metallic applications, milling with polycrystal diamond and carbide is very impressive.
It is common to increase tool life by 100 times, and other benefits include better Part tolerance control, better surface finish and less burrs.
This means less scrapping, more machine uptime and better tool cost adjustments.
If the user can get a tool life of 100 times, in some cases, it is difficult not to use polycrystal diamond in these applications.
With these types of results, high-yield applications of non-ferrous and non-metallic materials will be completed entirely through polycrystal diamonds.
The Carbide will be out of date when these milling applications are carried out.
However, hard alloys may still have a place in smaller work shops without high production lines or in areas where tools with lower costs are more practical.
In severe rough machining operations where toughness is required to maintain an ultra-high force, impact-resistant carbide is still valuable.
Due to the new composite materials, polycrystal diamond has become very important in the aerospace industry.
Face milling, end milling, drilling and hole expansion are common operations.
Aerospace materials such as metal matrix composites and graphite epoxy composites have great grinding properties.
Cemented carbide is also an existing cutting tool material, and it is currently being replaced by the one for many applications.
The polycrystal diamond has excellent wear resistance and the result is more stringent dimensional tolerance control and improved surface finish.
With the ability to maintain sharp edges for long periods of time, the tool enables a clean cut when the chip is formed.
This is conducive to the processing of complex microstructure of new composite materials.
The reduction of scrap and the excellent quality of parts sometimes even exceed the weight of the tool
Benefits of saving life costs.
Another new application is the milling of different metals (
Aluminum and cast iron)engine blocks.
At the GE Super grinding plant, we think this is a great opportunity for polycrystal diamond.
A great deal of research has been done internally and with car manufacturers.
Interest in processing these types of engine blocks comes from Europe, Japan and the United States.
The test of this reveals a significant trend in machining parameters (
Feed and speed).
In order to optimize the generation of milling tool geometry and surface finish, additional testing is being carried out.
At this point, there are very few facilities in production to process this type of engine block.
But automakers are also looking at this trend in the near future.
A key to success when applying polycrystal diamond is to pay close attention to the milling tool and blade geometry.
In many situation under Because carbide was applied to milling operation high rakeangles (20 [degrees])
High clearance angle (25 [degrees])wereused.
These geometries are no longer needed as milling applications are converted to polycrystal diamonds.
Simplify the front corner in many cases (+5 [degrees])
And clearance angle (+10 [degrees])
A strict setting has been given to allow successful application in milling through tough materials or severe interruptions and to produce excellent tool life.
Using the reduced geometry of polycrystal diamond continues to produce high quality parts at high speed. PCD Compax [R]
At work, replacing standard carbide blades with blades manufactured using GECompax tool blanks enables aluminum alloy fuel injection pump body manufacturers to reduce the cost of milling tools per piece of surface by 50%, substantially improve to maintain higher quality.
The operation is milling 8. 4\" X 1. 4\" (210 mm X 35 mm)face.
Usually, from 0. 140\" to 0. 160\" (3. 5 mm to 4 mm)
Remove ofstock during face milling operations.
Quality requirements are critical.
The inner surface must be flat]+or -]0. 0016\" ([+ or -]0. 04 mm).
The maximum allowable surface roughness is 48 micro-inches Ra (1.
2 Micron Ra).
The material is a cast aluminum alloy with a silicon content of 5 to 7%, which can quickly reduce the cutting edge of the carbide blade, resulting in reduced cutting efficiency and uncertain size control, unless the insert is replaced before these problems occur, the completion is poor.
When using a standard square rotatable carbide blade (
Eight-sided grinding)
The cutting edge life of the new blade is only 2375 pieces, and the cutting edge life of the re-grinding blade is 5000 pieces.
Frequent downtime for tool replacement reduces productivity.
The edge life of the Compax blank plug-in running under the same conditions is 402,500 pieces.
This is 169 times the life of the new carbide cutting edge and 80 times the life of the cutting edge.
The annual production demand is 420,000 pieces.
After initial installation, The Face mill with the PCD knife blade will remain on the machine for nearly a year.
In contrast, in the same period, the surface steel with carbide blades must be replaced 124 times, thus reducing the productivity of the machine accordingly.
When all the tool costs are taken into account, face milling cutters with PCD knife blades may be the most economical option for this operation.
For the face machine with carbideinserts, the tool cost per piece is less than half.
Quality improvement is another benefit.
There is no problem keeping the required surface flat.
16 to 32 inches, Ra (0. 4 to 0.
8 cents, Ra)range.
With carbide blades, the surface finish is inconsistent, ranging from 18 to 48 microinches, Ra (0. 45 to 1.
Ra) 2 microns.
The development of milling multi-Crystal cubic bn cutting tools for black materials has improved the removal rate of hard-to-process materialsto-
Mechanical materials will increase significantly.
However, the processing process and conditions selected when using this tool material should take advantage of the excellent mechanical and thermal properties that pcbn has.
This material has obvious advantages in processing steel and gray cast iron.
Since the introduction of multi-Crystal cubic bn by GEin in early 1970, many things have happened in the application development of the product, which makes use of its excellent mechanical and thermal properties.
New machine tools with higher spindle speeds and superior rigidity are being designed to take advantage of the potential of these features.
The PCBN product of GE Super grinding is called BZN [TM]compacts.
They are made up of micron-grade multi-crystal layers
The size of CBNcrystals, bonded together while bonding to the high of the atungsten hard alloy matrix
High temperature-
Pressure process.
The PCBN layer exhibits the high hardness and high toughness of CBN from the random crystal orientation and carbide support.
High-designpressure, high-
For the manufacturing process, the temperature device makes the cylindrical shape the most effective.
Many different shapes and sizes of PCBN blanks and blades are usually cut from round blanks.
These products can then be welded to the body of steel or tungsten copper tools or used directly as plug-ins.
With diamond grinding wheels, the brazing tip tool can form the desired geometry.
Milling with PCBN. By definition, the milling process is a form of material removal where there is a relative movement between the workpiece material and the rotating tool (
There are usually multiple sides).
This process is characterized by an extremely high material removal potential.
The material removal process currently performed on many steel components includes rough forming, hardening under soft conditions, and then grinding to the final size.
While this process can be used to produce finished parts, the production time is often quite long.
With the emergence of PCBN ultra-abrasive cutters, the strategy of AC material removal should be studied.
These may involve hardening of steel members before machining and PCBN milling to the final size.
One such application is in gear production. Hardend-
The process of gear milling gear finishing is achieved through various methods.
After hardening, gear grinding, machining or a combination of these processes can be used.
Typically, smaller gears are overlapped or ground to the desired profile.
Larger gears are usually machined and then ground to provide pitch accuracy.
Many machines have been designed for this application.
These machines operate on up to eight axes and use milling cutters to produce straight, spiral and spiral gears.
These machines are designed around the use of tunsten carbide.
The use of pcbn was investigated under the conditions listed in Table 1.
The results clearly show that the PCBN tool significantly improves the life of the two tools (10-times)
And material removal rate (3-times).
In addition, due to the slow wear rate of the PCBN tool, the pitch accuracy from the tooth to the tooth is significantly improved.
This application is just an example of how PCBN can be used to mill hardened steel to improve productivity and parts quality while reducing overall processing costs. Cast-
Cast iron milling is still an important component material due to its good physical properties and low cost combination.
When processing gray cast iron and hard alloy tools-
Coating and uncoated-
Use at a relatively slow speed.
Recently, the use of nitrogen Silicon tools has increased the cutting speed.
When milling gray iron, nitrogen Silicon has certain physical performance advantages over carbide.
High adoption of polycrystal cubic boron carbide
The rapid processing of cast iron has begun.
However, most of the use of PCBN in processing gray cast iron is in singlepoint turning.
GE application engineers conducted a series of tests to determine the possibility of using PCBN
High speed milling of cast iron.
The machine used is a Springfield grinder modified with Bryant\'s high-speed spindle (50,000 RPM)
Attached to the pillar. A CNC work-
In order to increase flexibility, the workpiece fixing table is added to the grinder.
Test conditions for testing are shown in Table 2.
Preliminary tests were carried out on the Springfield machine to compare the properties of PCBN and silica.
The cutting speed of 5800, 9800 and 13,100 sfm was evaluated using a 2 \"diameter cutter.
Testing at 2900 sfm is not possible, as insufficient power can be obtained at lower RPM.
Therefore, a lower speed test must be performed on different machines (Fritz Werner)
Knife with an8 \"diameter.
The test results are shown in Figures 1 and 2.
Due to lower speed testing on different machines, the data is presented on separate charts.
The results show that extremely high cutting speed and metal removal rate can be achieved by using PCBN.
In terms of cutting speed, there are certain limitations in nitrogen Silicon cutters.
In today\'s industry, the typical cutting speed is about 3000 sfm.
Even at this cutting speed, PCBN shows an obvious advantage in terms of tool life.
The PCBN tool follows the predicted wear pattern, which is typical cutting-tool behavior.
A high initial wear pattern is formed at the edge of the tool.
It is followed by a steady-state wear pattern until rapid wear finally occurs.
Even at 13,100 sfm cutting speed, the slope of the wear curve seems to be similar to the lower speed range.
The difference between the test conditions is only the initial wear mode.
Milling cylinder heads of many auto parts today (
Engine block, cylinder head, etc)
Or made of cast iron.
Although aluminum has replaced some of these components, cash iron will remain a widely used material in the future.
For many cast iron parts, the milling process is still carried out at low speed by the hard alloy.
Like the car cylinder head, nitrogen silicon is used in several applications for high-speed milling.
Machining the cylinder head under the conditions shown in Table 3.
PCBN tools process a total of 17,000 cylinder heads.
This is compared to completing 1900 head nitrogen Silicon before the dimensional tolerance becomes a problem.
Milling operation without coolant.
Due to the rapid heating and cooling of the cutting tool during milling, the tool has the possibility of failure due to thermal fatigue.
Coolant has a negative impact on performance and is not recommended.
Other productivity improvements include shorter downtime for tool changes and shorter tool setup times.
The tool geometry of the tool has a significant impact on the performance of the PCBN tool, whether it is machined cast iron or steel.
As shown in Figure A, the angle from the tool center line to the tool cutting edge is measured.
Negative axial-
The negative radial rake knife is one of our existing standard geometry. (
The other is the positive axis.
Positive radial rake, negative radial-
Forward axial and high forward radial-axial. )
The important advantage of double elimination fracturing is that the tool is able to withstand higher cutting force without breaking.
Edge preparation for cutting tools is also important.
Anedge chamfer with size 15 [degrees]X 0. 008\" (Sketch B)isrecommended.
This leads the cutting force to the center of the tool, where there is more support.
When the surface of the milled part has an uneven scale surface or has a serious interruption, add 0.
002 \"it is recommended to hone at the bottom edge of the chamfer.
The combination of negative tool geometry and chamfer will result in higher cutting force and more horsepower required.
However, this geometry will allow the PCBN tool to withstand the resulting force better.
Conclusion these results clearly indicate that the machining process needs to be re-evaluated according to the capabilities of the PCBN tool.
The use of PCBN tools can be an effective way to increase material removal rates and productivity while reducing overall processing costs.
In evaluating the machining process, the following factors should be taken into account: * milling hardened steel with PCBN tools is a viable process.
The cutting speed of 400 to 500 sfm has significant advantages in tool life and metal removal rate. * High-
The use of PCBNtooling can quickly mill gray cast iron, but the cutting speed cannot be achieved by using nitrogen Silicon (. sup. 3000sfm).
* In addition to the appropriate tool edge chamfer, Double Negative milling tool geometry is required.
This will provide maximum support for cutting edges and increase tool life.
GE\'s future ultra-abrasive materials have been devoted to chemical vapor deposition (CVD)technology--
Another technique for growing diamonds since the mid80s.
CVD is a method of producing diamonds at relatively low temperatures and below atmospheric pressure.
One of the advantages of CVD diamond is that it has a potential manufacturing tool with longer leg lengths than conventional technology.
In addition, once certain technical problems have been overcome, the use of CVD diamonds with 3D or curved geometry may create tools-
Eliminate some shape limitations of the traditional tool.
There is still a long way to go before CVD diamond tools can be used for a wide range of commercial purposes.
But there are a lot of activities going on around the world.
Some companies in Japan have introduced prototype tools using CVD diamond technology.
However, GE believes that it is essential to continue to improve high-tech
Before the day when CVD Diamond became a commercial reality, the pressure tool product.
kingtool aluminium machinery saves time and increases productivity because it's one of the most complete sources of business and contact information.
Kingtool Aluminum Doors and Windows Machinery Co., Ltd. is a professional manufacturer of offering some of the best in class drilling machine solutions to global market. Click Kingtool Aluminium Machinery to learn more.
Kingtool Aluminum Doors and Windows Machinery Co., Ltd. has extented its range of manufacturing scale, which satisfys customers' needs.
Custom message
Chat Online 编辑模式下无法使用
Chat Online inputting...