In high speed cutting and hard metal cutting, controlling heat in metal cutting is one of the mainest factors. Came a few years in the past, make in the mould, the industry such as parts of an apparatus of aerospace, medical treatment, cutting of hard metal of high speed cutting and temper by dipping in water already became quite general, although its machine craft to did not produce too big change, but the requirement to cutting cutting tool however already not to be named on the same day with. To be opposite to the requirement of cutting tool mould and other part undertake effective high speed cutting and hard cutting, requirement cutting tool can bear the heat in metal cutting that speed of faster face cutting causes. In addition, still must undertake preparation to the cutting blade of cutting tool, make its can bear the cutting power that high speed milling produces and wear away. (1) cutting tool coating uses coating is the way with increase cutting tool hear resistance the most important. The hard steel of temper by dipping in water that exceeds HRC40 in treatment hardness or undertaking exterior cutting speed exceeds 800sfm (245m/min) when high speed cutting, tiAlN (AlTiN) coating cutting tool is first-rate choice. But, because have a lot of different companies,manufacturing coating cutting tool, because coating of this avery kind of can have a lot of distinct change. Better to decide the treatment effect of which kind of coating, the means of only experiments through cutting namely. Although most tool manufacturer is met,the coating cutting tool that manufactures to oneself undertakes cutting experiments, but some of tool manufacturer may not be aimed at high speed cutting and hard cutting technically to undertake cutting tool function experiments. Accordingly, develop function first-rate for the help applicable coating, need searchs the tool manufacturer that stuff of a hard to temper by dipping in water metal had extensive cutting experiments. Current, alTiN coating remains optimal option, and in the future, silicon may include in the constituent of coating (Si) element. As rotate speed of machining center main shaft rise ceaselessly, the assorted function of coating and hard alloy matrix also must with when all is entered, can bear the higher temperature of the generation in treatment. Si element is added in coating, will raise its to fight oxidation function greatly, make coating can be in thereby be as high as 1, the temperature of 100 ℃ leaves the job. (2) appearance of geometry of cutting tool of appearance of cutting tool geometry also can produce main effect to controlling heat in metal cutting. Cut bits to take away heat in metal cutting to use, the design of appearance of cutting tool geometry must consider his to cut bits purify function. Development gives bit of head dummy of a kind of ball now, have on its grind the three-dimensional helix structure that make, it can make cutting more flowing, oscillatory the smaller, performance that discharge bits is better, all generation that these characteristics are helpful for reducing heat in metal cutting. To use these new-style cutting tool effectively, need uses new treatment method. Normally, to maintain the flow that cut bits is mixed take away quantity of heat, should use taller main shaft to rotate speed, bigger feed is led and cut deep amount lesserly. When appearance of geometry of affirmatory cutting tool, must follow principle of a few directiveness. For example, must check the precision requirement that uses cutting tool carefully, jump to radius of circular arc of the diameter of cutting tool, point of a knife and diameter the error should try to consider. The precision of cutting tool is taller, the part that treatment gives is more accurate. The cutting tool way that keeps lesser jumps, the treatment appearance with can be obtained better is bright and clean spend and dimension precision, and longer cutting tool life. The milling that ball head milling cutter appears to fit complex and three-dimensional profile most machines a kind of Shuang Ren that has bigger core way. We do not recommend the milling cutter that collects appliance to have more where a thing can be put to best use, can hamper because of addition the crucial point a bits. In addition, if use milling cutter to carry a ministry to undertake cutting, in milling cutter upright ministry has two where a thing can be put to best use only, and the upright ministry in 3 blade milling cutter has a where a thing can be put to best use only. The technical level of the bit type milling cutter that milling cutter of type of ① razor blade uses at mould treatment and common treatment can have not had breakdown ground to finish great majority to machine the task. Use bit type milling cutter to be able to undertake all sorts of treatment are operated, be opposite especially large and medium-sized mould antrum and model the treatment of core, because the diameter of bit type milling cutter suits this kind of treatment very much. Bit type milling cutter (diametical 12mm above) have very good cutting property in rough machining and finish machining. The bit type milling cutter with lesser diameter basically is used at finish machining and certain load lighter rough machining. Milling cutter of ② whole hard alloy is in certain treatment domain, milling cutter of integral hard alloy still has an advantage. The clearest case is, when cutting tool diameter is less than 6mm, need chooses milling cutter of integral hard alloy, because of the diameter such small bit type milling cutter has not develop a success. One kind is called " cycloidal milling " treatment new method also needs to choose integral hard alloy to establish milling cutter. Cycloidal milling means basically is used at mill chamfer, but also some of CAM software develops personnel to applying its at model antrum milling. Cycloidal milling must be used cut greatly mix greatly very small step pitch, its treatment campaign turns for very flowing circular arc a cutting, every turn the distance with ongoing circuit is equal to quantity of its step pitch roughly. This kind of treatment uses integral hard alloy to establish milling cutter commonly, because it has many cutting blade, allow to use very high feed rate. Normally, still should use the helix chamfer milling cutter that has big helix angle, it can realize very flowing cutting, machine a wonderful surface bright and clean degree. A defect that cycloidal milling machines is, if of cutting tool dangerous extend a capacity bigger, incidental when treatment bending. The cutting theory that the bit type milling cutter that ③ uses cutter hub of integral hard alloy goes thinks, cutting tool hangs those who extend length and cutting diameter to compare, it is the critical factor that should choose milling cutter of integral hard alloy or bit type milling cutter certainly. And now, introduce bit type milling cutter as cutter hub of hard alloy of will new-style whole, this kind of theory also got oppugn. Now, in the milling treatment that exceeds 12mm in cutting tool diameter, already had the sufficient reason that chooses milling cutter of integral hard alloy rarely. Previously, steeliness cutter hub often lacks the tigidity that needs with the place when hanging the cutting tool that extend a capacity to undertake big cutting parameter is machined greatly. Nowadays, in this kind of treatment, can use on hard alloy cutter hub clip holds the razor blade with relatively low cost, and need not use the integral hard alloy with higher cost to establish milling cutter. The other dominant position of bit type milling cutter still includes better flexibility, repeat precision and treatment place accessibility (cutting tool is longer) . It is easier already that the milling cutter of type of big feed razor blade that weak data of ④ rough machining uses processes the workpiece data that passes heat treatment beforehand with current cutting tool milling. And milling cutter of a kind of type of new-style razor blade that is used at rough machining weak data already also was come out by development. The geometrical appearance of this kind of milling cutter suits to be mixed with high rotate speed, big feed small cut deep undertake machining, compare with photograph of traditional milling cutter, its cutting rate is rapidder, treatment efficiency is taller. Machining case is the example of a treatment that uses cutting tool of appearance of this kind of geometry below. Machine a condition: Machine tool: 5 axes of FPT Dino machine a machine tool (rotate speed of the largest main shaft: 10, 000r/min) ; Cutting tool diameter: 25.
4mm; Cutting deepness: 0.
9mm, cutting width: 19mm; Main shaft rotate speed: 3, 800r/min; Feed rate: 7, 874mm/min; Cutting tool is dangerous extend a capacity: 100mm; Oily mist is cooling. In treatment, because the main shaft of this machine tool is inside limits of inferior rotate speed torque is finite, because this user was not on this machine tool,enter rough machining of the foreword before travel. Use 3, the main shaft rotate speed of 800r/min undertakes machining, in the power range that enters main shaft of this machine tool with respect to possible point. Undertake with the cutting tool that uses bigger diameter before rough machining photograph is compared, use a diameter for 25.
The cutting tool treatment of 4mm can win the work of more adjacent and final figure. Finish machining nowadays, carry cutting tool, machine tool and coat optimize combination, to most mould material, can in order to exceed 1, 200sfm (365m/min) exterior cutting speed has precision work, the cutting speed of some finish machining can be achieved even 3, 000sfm (915m/min) . Because cutting speed and feed rate are very high, machine cycle time to shorten thereby, raised workpiece surface quality to offer an opportunity at the same time. Finish machining obtains successful key to depend on, ensure the workpiece appearance after semifinishing machining is close to his as far as possible final figure, make the material purify volume of finish machining cutting tool won't happen to fluctuate considerably thereby. In finish machining, the material purify quantity of cutting tool agrees equably more, force of cutting of cutting tool susceptive is steadier, can provide the cutting tool life with can forecast a gender better thereby, can shorten treatment cycle time. Before the main appearance of finish machining workpiece, also be helpful for prolonging cutting tool life to undertaking at sharp point of a knife passivation is handled too, improve treatment the surface is bright and clean degree, can apply at unmanned value to defend treatment. When having precision work to most mould material, can use compress air gush to blow or means of oily mist refrigeration. When high speed cutting, unfavorable use cooling fluid pouring style is cool, because be below the alternant thermal shock that the high temperature that cutting produces and cooling fluid drop in temperature, may make hard alloy cutting tool produces disintegrate or generation crackle. Oily mist refrigeration can offer first-rate to machine the surface bright and clean degree, be helpful for prolonging cutting tool life at the same time. Brief summary is in high speed cutting and hard cutting treatment, controlling heat in metal cutting is the mainest factor, want to be able to control heat in metal cutting only, machined a process to stride one stride to successful control. Hard milling treatment raised very tall requirement to knife handle and blade of cutting tool cutting, still need to undertake to milling parameter at the same time certain adjust. The workpiece data with complete hard temper by dipping in water is very hard cutting, the cutting tool when treatment should bear more heat in metal cutting. If machine a condition to allow, use ball head milling cutter to be able to fall the ill effect of heat in metal cutting to lowest. In hard milling, to reduce heat in metal cutting, should reduce cut mix greatly step pitch. Because reduce those who cut deep and accessary generation to cut bits to reduce small effect, make cutting tool can with taller every tine feed (Fz) undertake machining. Helicoid milling cutter, bovine bazoo milling cutter and square shoulder milling cutter also may apply to hard milling treatment, and cutting blade is sharper (radius of circular arc of point of a knife is smaller) , the heatproof sex of cutting tool is poorer. CNC Milling