Precision CNC machining parts The machining quality mainly is refers to the work piece the
processing precision and the surface quality (including surface roughness,
residual stress and superficial hardening).Along with the technical progress,
the machining quality enhances unceasingly.The 18th century later periods, the
machining precision counts by the millimeter; At the beginning of 20th century,
machining precision Gao Yida 0.01 millimeter; To the 50's, the machining
precision has reached a micron level; The 70's, the machining precision
enhances to 0.1 micron.
The influence machining quality primary
factor has aspects and so on engine bed, cutting tool, jig, work piece
semifinished materials, technique and processing environment.Must improve the
machining quality, must take the suitable measure to the above various aspects,
like reduces the engine bed work error, selects the cutting tool correctly,
improves the semifinished materials quality, the reasonable arrangement craft,
the improvement environmental condition and so on.
Precision CNC machining parts Enhances the cutting specifications to enhance the material excision
rate, is enhances the machining efficiency the essential way.The commonly used
highly effective machining method has the high-speed cutting, the force
cutting, the plasma arc heating cuts and vibrates the cutting and so on.
The grinding speed is called the high-speed
grinding in 45 meters/second above es the high-speed cutting (or grinding) both
may enhance the efficiency, and may reduce the surface roughness.The high-speed
cutting (or grinding) requests the engine bed to have the high speed, the high
rigidity, the high efficiency and the vibration-proof good craft system;
Requests the cutting tool to have the reasonable geometry parameter and the
convenience tight way, but also must consider the safe reliable chip breaking
method.
Precision CNC machining parts The force cutting refers to the roughing feed or cuts the deep
machining greatly, uses in the turning and the grinding generally.The force turning
main characteristic is the lathe tool besides the main cutting edge, but also
some is parallel in the work piece has processed superficial the vice-cutting
edge simultaneously to participate in the cutting, therefore may enhance to
feed quantity compared to the general turning several times of even several
http://www.wendangku.net/doc/90cc2c195ef7ba0d4b733b53.html pares with the
high-speed cutting, the force cutting cutting temperature is low, the cutting
tool life is long, the cutting efficiency is high; The shortcoming is processes
the surface to be rough.When force cutting, the radial direction cutting force
death of a parent is not suitable for to process the tall and slender work
piece very much.
The vibration cutting is along the cutting
tool direction of feed, the attachment low frequency or the high frequency
vibration machining, may enhance the cutting efficiency.The low frequency
vibration cutting has the very good chip breaking effect, but does not use the
chip breaking equipment, makes the knife edge intensity to increase, time the
cutting total power dissipation compared to has the chip breaking installment
ordinary cutting to reduce about 40%.The high frequency vibration cutting also
called the ultrasonic wave vibration cutting, is helpful in reduces between the
cutting tool and the work piece friction, reduces the cutting temperature,
reduces the cutting tool the coherence attrition, thus the enhancement cutting
efficiency and the processing surface quality, the cutting tool life may enhance
40% approximately.
To lumber, plastic, rubber, glass, marble,
granite and so on nonmetallic material machining, although is similar with the
metal material cutting, but uses the cutting tool, the equipment and the
cutting specifications and so on has the characteristic respectively.
The lumber product machining mainly carries
in each kind of joiner's bench, its method mainly has: The saw cuts, digs cuts,
the turning, the milling, drills truncates with the polishing and so on.
The plastic rigidity is worse than the
metal, the easy bending strain, the thermoplastic thermal conductivity to be in
particular bad, easy to elevate temperature the conditioning.When cutting
plastic, suitably with the high-speed steel or the hard alloy tools, selects
the small to feed quantity and the high cutting speed, and uses compressed air
cooling.If the cutting tool is sharp, the angle is appropriate, may produce the
belt-shaped scrap, easy to carry off the quantity of heat.
Glass (including semiconducting material
and so on germanium, silicon) but degree of hardness high brittleness is big.To
methods and so on glass machining commonly used cutting, drill hole, attrition
and polishing.To thickness in three millimeters following glass plates, the
simple cutting method is with the diamond or other hard materials, in glass
surface manual scoring, the use scratch place stress concentration, then uses
the hand to break off.
To the marble, the granite and the concrete
and so on the hard material processing, mainly uses methods and so on cutting,
turning, drill hole, shaping, attrition and polishing.When cutting the
available circular saw blade adds the grinding compound and the water; The
outer annulus and the end surface may use the negative rake the hard alloy
lathe tool, by 10~30 meter/minute cutting speed turning; Drills a hole the
available hard alloy drill bit; The big stone material plane available hard
alloy planing tool or rolls cuts planing tool shaping; The precise smooth
surface, available three mutually for the datum to the method which grinds, or
the grinding and the polishing method obtains.
Cutting tool in hot strong alloy
application
The aviation processing also changes
rapidly. For example, nickel base heat-resisting alloy like several years ago
the most people had not heard Rene88 now occupies to the aircraft engine
manufacture uses the total metal quantity 10~25%. Has very good showing and the
commercial reason regarding this. For example, these heat strong alloy will be
able to increase the engine endurance moreover to permit the small engine work
on the big airplane, that will enhance the combustion efficiency and reduces
the operation cost. These tough good materials also present the expense on the
cutting tool. Their thermal stability causes on the knife point the temperature
to be higher, thus reduced the cutting tool life. Similarly, in these alloy
carbide pellet remarkably increased the friction, thus reduces the cutting tool
life.
As a result of changes in these conditions,
can be very pleased to have processed many titanium alloys and nickel-based
alloy materials C-2 hard metal alloys, in the application to today's cutting
edge of blade to the crushing and cutting depth of the trench lines badly worn.
But using the latest high-temperature processing of small particles hard metal
alloys to be effective, cutlery life improved, but more importantly to enhance
the reliability of applications in high-temperature alloys. Small particles
hard metal than traditional hard metal materials higher compression strength
and hardness, only a small increase in the resilience of the cost. And resulted
in high temperature alloy processing than traditional hard metal resistance
common failure mode more effective.
PVD (physical gas phase deposition) coating
also by certificate effective processing heat-resisting alloy. TiN (titanium
nitrides) the PVD coating was uses and still was most early most receives
welcome. Recently, TiAlN (nitrogen calorization titanium) and TiCN (carbon
titanium nitrides) the coating also could very good use. In the past the TiAlN
coating application scope and TiN compared the limit to be more. But after the
cutting speed enhances them is a very good choice, enhances the productivity in
these applications to reach 40%. On the other hand, is decided under the low
cutting speed in coating superficial operating mode TiAlN can cause to
accumulate the filings lump afterwards, micro collapses with the trench
attrition.
Recently, used in the heat-resisting alloy
application material quality already developing, these coating but became by
several combinations. The massive laboratories and the scene test has already
proven this kind of combination and other any kind of sole coating compares in
time the very wide scope application is very effective. Therefore aims at the
heat-resisting alloy application the PVD compound coating possibly to become
the focal point which the hard alloy new material quality research and
development continues. With the MTCVD coating, the coating ceramics gather in
the same place, they hopefully become a more effective processing to research
and develop newly are more difficult to process the work piece material the
main impact strength.
Dry processing
Including the refrigerant question is
technical and the commercial expansion industrial production tendency another
domain which the cutting tool makes. North America and the European strict
refrigerant management request and the biggest three automobile manufacturer
forces them the core supplier to obtain the ISO14000 authentication (the
ISO9000 environment management edition), this causes the refrigerant processing
cost rise. To the car company and their core supplier said obviously one of
responses which welcome is in the specific processing application avoids
completely the refrigerant the use. This kind did the processing the new world
to propose a series of challenges for the cutting tool supplier.
Recently, already appeared some to concern
this topic to promulgate the speed, to enter for, the coating chemical
composition and other parameters very substantial comprehensive nature very
strong useful technical papers. Wants to concentrate the elaboration in here me
"does the processing viewpoint" in the operation and commercial
meaning automobile manufacturer new.
The metal working jobholders can the very
good understanding related refrigerant use question, but majority cannot
understand concerns except the technical challenge (for example row of filings)
beside does the processing question in the cutting tool - work piece contact
face between. Usually may observe to the refrigerant disperser scrap which
flows out, but the pressure surpasses 3,000 pounds/An inch 2 high speed
refrigerant also can help to break the filings, specially soft also the
continual scrap can cause in the cutting tool - work piece contact face
trouble.
Uses does the cutting craft the components
result is the engine bed uses the wet type processing components to be hotter
than. Whether before you do allow them to survey in the open-air natural
cooling? If processes newly the hot components put frequently to the turnover
box, elevates the environment temperature, whether components full cooling and
just right enough permission precision examination? Also has the handling side
several dozens on hundred components to be able to operate the worker to
increase the extra burden.
With many cutting tools/The work piece
technical question same place, these latent questions need to state whether
dryly adds the ability line. Luckily, has very many ways to elaborate these
questions. For example, the compressed air was proven row of filings becomes
the question in very many applications the situation to have the successful
echo.
Another plan is called MQL (minimum
lubrication) a technology, it replaces the traditional refrigerant by the
application the quite few oil mists constitution. This is a recognition
compromise plan, this kind of minimum technology can large scale reduce the
refrigerant the headache matter, moreover the smooth finish which processes in
many applications very is also good. This domain still had very many research
to do, moreover the cutting tool company positively participated in such
research was absolutely essential. If they will not do fall behind the
competitor, will be at the disadvantageous position.
In the factory the special details design
other perhaps better plan according to the world in. The manufacturing industry
jobholders possibly still could ask why they do have to use recent development
the technology to replace the refrigerant method diligently which the tradition
already an experience number generation of person improved enhances, because
implemented especially does the experiment and the defeat which the processing
or the subarid processing produced possibly causes the higher short-term cutting
tool cost. The concise answer is when the bit probably accounts for the model
processing components cost 3%, the refrigerant cost (from purchases to
maintenance, storage, processing) can account for the components cost 15%.
Perhaps does the dry processing is not all
suits to each application, but above discusses likely other processing
questions are same, needs from a wider operation, the environment and the
commercial angle appraises. Will be able to help the cutting tool company which
the customer will do this to have the competitive advantage, but these will not
be able to provide unceasingly is in the passive position.
Cutting tool and nanotechnology
Can fiercely change the cutting tool
industry the enchanting new domain is the miniature manufacture, or the
processing small granule forms the product which needs. Must refer to is its
here does not have about the cutting tool miniature manufacture first matter;
Second must say the matter is it is not remote.
Why the miniature manufacture and are the
cutting tool related. Because most main is the particle size smaller, the hard
alloy toughness of material better also is more wear-resisting. (Some experts
define with the nanometer level pellet for are smaller than 0.2 mu m, but other
people persisted a nanometer pellet had to be smaller than the hard alloy tools
prototype which 0.1 mu m) made already to complete and the test,It is said that
wear resistant theatrically increase. The question is the nanometer level hard
alloy pellet cannot depend on the smashing big material formation, they are
certain through the smaller material constitution, but processes the molecular
level granule is not easy and the economical matter.
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