The milling of spare parts of aerospace titanium alloy is machined

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In a lot of aerospace application, titanium and its alloy are replacing traditional aluminium alloy. Nowadays, 42% what the titanium material that aerospace industry uses up occupies the whole world to produce gross about, and arrive from now 2010, the demand that predicts pair of titanium material will continue to grow with the speed of two digit. New generation plane needs to make full use of the performance that titanium alloy provides, no matter be business uses machine or warplane market, prompting the demand of pair of titanium alloy. Boeing 787, battleplan of bird of prey of empty guest A380, F-22, F-35 atttacks battleplan jointly (also call lightning Ⅱ ) waited for new model to use data of many titanium alloy. Alloy has the advantage titanium of titanium alloy material to rupture high strenth, high tenacity and good corrosion resistance and but weldability. Use composite material structure increasingly as plane airframe, titanium base material expects the scale that is used at airframe also will increase increasingly, the combinative function because of titanium and composite material far excel aluminium alloy. For example: Compare with aluminium alloy photograph, titanium alloy can make the life of airframe structure rises 60% . The intensity with titanium extremely high alloy / density is compared (amount to 20 ∶ 1, namely weight can be reduced 20% ) to reduce the weight of large component part (the main challenge that this is pair of plane stylist) provide understanding definitely plan. In addition, the Gao Naishi sex with titanium inherent alloy (compare with rolled steel photograph) OK and economic aircraft runs the cost with care and maintenance daily. The treatment that because compare common alloy steel,needs bigger process capability is more difficult, because this thinks normally,titanium alloy belongs to difficult treatment material. The metallic purify rate of typical titanium alloy is most common steel or stainless steel only 25% the left and right sides, the time that because this processes work of alloy of a titanium,need spends is treatment steel about 4 times. Machine the demand that increases increasingly to titanium alloy to satisfy aviation manufacturing industry, manufacturer needs to increase productivity, because this need understands the effectiveness with titanium alloy politic treatment better. The treatment of typical titanium alloy workpiece is from forging those who begin, win final workpiece external form by purify till the material of 80% . As the rapid growth of aviation component market, manufacturer people had felt ability not equal to one's ambition, add inferior and increasing treatment requirement, bring about titanium alloy process capability to be in nervous condition apparently. Of manufacturing industry of a few aviation get army the company oppugns existing machining ability publicly even whether the treatment job that completes work of alloy of all and new-style titanium. Because these workpiece are normally,make by new-style alloy, because this needs change treatment means and cutting tool data. Alloy of titanium of titanium alloy Ti-6Al-4V has 3 kinds of different configuration: α titanium alloy, α - β titanium alloy and β titanium alloy. Business cannot have heat treatment with pure titanium and α titanium alloy, but have normally good but weldability; α - β titanium alloy can have heat treatment, great majority also is had but weldability; β and alloy of accurate β titanium can have heat treatment completely, and also have commonly but weldability. The major common α that is used at turbine engine and airframe component - β titanium alloy is Ti-6Al-4V (Allvac Ti-6-4, abbreviation Ti-6-4) , the article represents the titanium alloy that ATI Allvac company produces with Ti-6-4, the main supplier that this company is titanium alloy (the titanium alloy that signed a 2.5 billion dollar with Boeing company recently is long-term supply agreement) . Additional, the ATI Stellram company that machines a solution with joint development of ATI Allvac company also uses these titanium alloy code name to describe treatment demand. Ti-6-4 has superior strength, rupture tenacity and fight fatigue integral performance, can make all sorts of product form. The Ti-6-4 of anneal condition can apply extensively at structural member. The little change that adopts chemical part and those who differ is thermomechanical handle technology, with Ti-6-4 producible the component that gives all sorts of different utility. Titanium alloy Ti-5Al-5V-5Mo-3CrTi-5Al-5V-5Mo-3Cr (abbreviation Ti-5-5-5-3) it is a kind of new-style titanium alloy that has market force quite. With β titanium alloy and α - photograph of β titanium alloy is compared, alloy of titanium of this kind of accurate β can offer the plane that combats piece of strength higher in the requirement the fatigue fracture tenacity that requires in component part application. With traditional titanium alloy (be like Ti-6-4 and Ti-10-2-3) photograph comparing, ti-5-5-5-3 provides some to be able to forging after complex form, heat treatment fight piece of intensity finally to be able to amount to 180ksi (every square inch thousands of pound) wait for function to make its make production aircraft the stuff that senior member and device of rise and fall have an outlook most. Have deliquescent heat treatment through be under β transition temperature or undertake in above of β transition temperature anneal is handled, control the grain dimension in microstructure and precipitation appropriately at the same time, ti-5-5-5-3 can acquire exceedingly good mechanical property. β transition temperature is the specific temperature of complex, here temperature issues alloy from α - β microstructure change is complete β microstructure. The change of chemical function and micromechanism makes titanium alloy can win the function combination of wide range, because this is in aviation component,win wide application. Bidayao raised the treatment difficulty of Ti-5-5-5-3 and Ti-6-4 appearance 30% , because this applies the hardware manufacturer of this kind of new-style alloy,devoting oneself to development to be able to not shorten the cutting tool life, corresponding treatment that does not lengthen manufacturing cycle craft. When machining titanium alloy, material hardness is a crucial factor. If hardness cost is too low (< 38HRC, titanium alloy will be tacky, cutting blade produces the tumor that accumulate bits easily. And hardness cost is higher (> 38HRC) titanium alloy will be right cutting tool material produces abrasion effect and make cutting blade wears away. Accordingly, speed of right choice treatment, feed and cutting cutting tool are crucial. The requirement to cutting cutting tool is mixed for quality of contented production cost, treatment deliver the goods on schedule the requirement that waits for a respect, new workpiece material and hardware design increased pressure to aviation component manufacturer. The treatment of these new material changed the requirement to cutting cutting tool, raise quality of life of metallic purify rate, cutting tool, product and the cutting tool that can expect not to have damaged life crucial to efficient, safe treatment. "Difficult treatment " it is an opposite concept, pass cutting cutting tool and the right combination that machine parameter, also can obtain efficient productivity. When processing work of alloy of aviation class titanium, cutting tool manufacturer is passed increase matrix density, design appearance of special cutting tool geometry, use accurate cutting blade the coating technology with abrade technology and new development in order to control a knife, the method such as the heat in metal cutting that labour interface produces, improved the performance of cutting tool greatly. In milling treatment, a of titanium alloy main character heats up conductibility extreme difference namely. As a result of the high strenth of titanium alloy material and low hot conductivity, the heat in metal cutting with extremely tall generation of the meeting when treatment (if do not impose control,can be as high as 1200 ℃ ) . Quantity of heat is not follow the eduction that cut bits or be absorbed by workpiece, gather on cutting blade however, so high quantity of heat will shorten greatly cutting tool life. Use special processing technique, improve cutting tool function and life likely (use correct processing technique to control temperature, can drop temperature 250 ~ 300 ℃ ) . Reduce quantity of heat to generate the radial that reduces cutting tool and workpiece and axial joint to be able to control the generation of heat in metal cutting. To titanium alloy, before because of overheat generation accumulates bits tumour, the adjustment to speed, feed, radial and axial joint term is very short. To reach proper cutting tool life, treatment titanium alloy needs only the biggest of 15% " joint arc length " , compare to it, arc length of the joint when processing common rolled steel is 50% ~ 100% . Reduce osculatory arc length to be able to raise cutting rate, in metallic excision rate does not raise below the premise of life of loss cutting tool. Use the cutting tool that cuts horn to be 45 ° or decrease thin cut bits, can increase blade of cutting tool cutting and the osculatory length that cut bits, reduce local high temperature thereby, prolong cutting blade life, also allow to use higher cutting rate at the same time. When bit geometry dimension designs cutting titanium alloy, razor blade of grinding of the week outside using reduces cutting to utmost ground pressure and with be machined attrition force of the surface is crucial. Bit geometry angle must be used horn, but this still can't ensure obtain optimum behavior. If use the small initiative part with higher intensity to enhance the first part of cutting blade, so use larger sub part (in order to obtain bigger pouring arris) press to enhancing bit to fight gender and prolonging cutting tool life is first-rate geometry design. In addition, slight passivation also conduces to protective cutting blade, dan Dun turns the noncombatant duty that dimension must be coordinated with cutting process photograph and keeps strict. When machining titanium alloy, need uses sharp cutting blade to cut material, but cutting blade is too sharp and easy bring about collapse blade and shorten cutting tool life. Proper passivation can protect cutting blade, avoid premature collapse blade. Correct bit geometry parameter can reduce the stress of pair of cutting tool material and pressure, make cutting tool is obtained longer life and improve treatment efficiency. The cutting horn of cutter hub and razor blade must be horn, in order to achieve progressive cutting effect, of the to concussion of generation of whole cutting blade unavailable expectation when avoiding cutting cut the result. If be not done so, work structure may happen be out of shape, make treatment cannot undertake. When sunken antrum milling and helix interpolation milling are undertaking sunken antrum milling and helix interpolation milling, must use inside cooling cutting tool, if possible sentence, should use constant to decide the cooling fluid of pressure, this is machined to deep sunken antrum or deep aperture especially important. When machining deep sunken antrum, use the cutting tool of lengthen of high density hard alloy that carries head of module type cutting to be able to rise tigidity and reduce bending to be out of shape, achieve optimal treatment result. The function of cooling fluid is to will cut bits to keep clear of from cutting area, avoid to may cause 2 cutting of cutting tool early failure. In the meantime, cooling fluid still conduces to the temperature that drops cutting knife, reduce workpiece geometry to be out of shape, prolong cutting tool life. Cutting tool of the other in undertaking with milling cutter helix interpolation hole milling can reduce knife library (if get first class) use, the milling cutter that uses a kind of diameter can machine the aperture that gives different measure. Grow ceaselessly in the application of aerospace industry as titanium alloy, the cutting technology that supports alloy of efficient treatment titanium also is developing ceaselessly. As a result of a large number of demand to process capability of titanium alloy spare parts, those workshops that use the most effective processing technique or manufacturer will be benefited above all. The company of solution Allegheny Technologies with in-house and integrated new generation is manufacturer of a many domain, section of the business below the banner includes metallic smelt to include metallic cutting again already, the union of these two domains makes this company is developing advanced material (the alloy that be like titanium) respect of treatment new method has an advantage. ATI Stellram company is the section of a business of company of the ATI Metalworking Products below Allegheny Technologies banner, it is in charge of undertaking to all new material that develop by ATI Allvac company function experiments machining, in order to decide structure of geometry of design of first-rate razor blade, cutting tool, matrix and coating structure and cutting parameter, make these new material are being made public appear on the market can undertake to its economy is machined effectively before the sale. In addition, as the delegate of Allvac, stellram is main aviation production enterprise and supplier of top-ranking aviation machinery component, can satisfy pair of workpiece material and cutting cutting tool the collective demand of two respects. The comprehensive understanding of inherent to material structure makes ATI Stellram company is in cutting tool matrix has an advantage on the design of distinctive recipe, one of its achievement are X-Grade technology, ATI Stellram says, this technology already was proved to be a kind of when process difficult treatment data reliable plan. Adopt research and development X-Grade technique, produced a kind of new hard alloy name, it can machine a condition to fall to lead material of effective cutting difficult treatment with extremely tall metal purify in what do not stabilize. Technology of X-Grade razor blade (matrix and coating) X-Grade razor blade used ruthenium / cobaltic alloy matrix, the generation of OK and counteractive hot crack and patulous, can achieve higher metallic purify rate. This matrix has stronger crystal to integrate matrix structure, improved the tenacity of cutting blade thereby. Say according to ATI Stellram, this base material and form of new cutting tool geometry and coating photograph are united in wedlock, can offer outstanding cutting tool combination to machine aviation alloy. Use X-Grade razor blade to be able to come true: Rate of ① metal purify rises 1 times; Life of ② cutting tool is added to 3 times; ③ treatment surface is bright and clean degree rise 30% . Can include 3 kinds of brands for chosen X-Grade razor blade (X400, X500 and X700) , be machined in the light of specific difficult cutting and razor blade of avery kind of is designed. They can use bit type of the standard, can install the bit chamfer in standard cutter hub mostly inside. But ATI Stellram says, optimal program is the cutting tool that uses special design in order to optimize the function of X-Grade razor blade. The discharges bits, aggrandizement chamfer that the knife chamfer design of these cutting tool can realize utmost cool with first-rate. Two kinds of cutting tool of this series include: ① 7710VR prevents turn button milling cutter: Mix round bit and contain the system of patent locking dislocation that displacement produces when preventing bit to lead cutting in big feed; ② 7792VX Gao Jin gives milling cutter: Compare with photograph of traditional cutting tool, metallic purify rate can rise 1 times. Outside giving the surface milling except Gao Jin, chamfer of sunken antrum of usable still Yu Xi, mill mixes 7792VX series cutting tool insert mill, because cutting force passes into main shaft along axial directly, because this can reduce main shaft attrition, increase cutting stability. Spare parts of aviation titanium alloy is to use ATI Stellram cutting tool and X-Grade razor blade to machine two example of spare parts of aviation titanium alloy under treatment check study. (1) machine example 1 by treatment spare parts: Enclothe outside titanium alloy (for military use) workpiece material: Ti-6Al-4V (Allvac Ti-6-4 alloy) work measure: 110" × 18" machines a description: Use match XDLT-D41 but the Gao Jin of ATI Stellram 7792VX of dislocation razor blade undertakes machining to milling cutter, the cutting tool life that thick mill machines achieves 156 minutes. Milling cutter: C7792VXD12-A3.

00Z5R; Knife chamfer amount: 5 razor blade: XDLT120508ER-D41; Brand: X500 (use X-Grade technology to design) Ap of axial cutting deepness: 0.

Ae of width of 080" radial cutting: 2.

Vc of 100" cutting speed: Feed of 131sfm every tine Fz: 0.

023ipt feed leads: 19.

Life of 2ipm cutting tool: 156 minutes / every time dislocation (every razor blade but dislocation 4) (2) machine example 2 by treatment spare parts: The turbine lamina of military airplane (new applying) workpiece material: Dimension of lamina of complete titanium alloy: 23.

6" × 11.

8" machines a description: Use deserve to prevent turn the lamina of airscrew of treatment of milling cutter of ATI Stellram 7710VR of round razor blade, the cutting tool life that thick mill machines achieves 110 minutes. Milling cutter: C7710VR12-A2.

00Z5R; Knife chamfer amount: 5 razor blade: RPHT1204MOE-421-X4; Brand: X700 (use X-Grade technology to design) Ap of axial cutting deepness: 0.

080" ~ 0.

Ae of width of 100" radial cutting: 0.

800" ~ 1.

Vc of 37" cutting speed: Feed of 265sfm every tine Fz: 0.

0086ipt feed leads: 21.

Life of 8ipm cutting tool: 110 minutes / every time dislocation (every razor blade but dislocation 4) CNC Milling CNC Machining