Titanium alloy has density low, taller than intensity, anti-corrosive wait for outstanding advantage, apply extensively in aerospace and its engine structure, the discretion of dosage of titanium alloy structural member already was become measure modern plane, tall hold in esteem one of important signs of more advanced than aviation engine technology sex. Laser of titanium alloy component becomes form technology quickly, it is raw material with titanium alloy powder, chase a deposit through stimulating Guang Rong to change (" grow make " ) , direct by model of spare parts CAD one pace completes component part of high-powered titanium alloy " close clean figuration " , it is one kind changes sexual short period, low cost, without model, digitlization, advanced production technology. Forging with whole tradition of alloy waiting for titanium makes technical photograph compare, laser of titanium alloy component has an organization into form technology quickly integrated and petty and even, mechanical performance is superior, need not forging treatment and forging mould, overall material utilization factor surplus of tall, machining time of small, CNC Machining is flexible and short, efficient wait for outstanding advantage. Through nearly 10 years tackle key problem, our country already took the lead in realizing laser fast figuration is large titanium alloy advocate bear the outfit machine application of force member. The feature of exterior form appearance that laser becomes part of form titanium alloy quickly, microstructure, mechanical function and size surplus be cast with the tradition and forging titanium alloy existence is apparent difference, craft of its machine cutting also forgings with the tradition difference of titanium alloy existence. The cutting that still becomes form titanium alloy quickly without concerned laser at present machines the research of craft to report. This task analysed laser to be made into alloy of form TA15 titanium quickly feature of exterior form appearance and hardness profile uniformity, the cutting technical properties such as the milling that the key studied to laser becomes component part of alloy of form TA15 titanium quickly, boring, bore, cutting machines choice of cutting tool material and milling craft parameter to optimize. Laser of university of aerospace of Beijing of experiment method choice becomes the component part of plane of TA15 titanium alloy of form to experiment as the model quickly. Laser of component part of plane of TA15 titanium alloy becomes form hind quickly according to (℃ of 750 ± 20) / (2 ～ 3)h, system of AC heat treatment undertakes going stress anneal. Use microscope of BX51M optical metallographic (electron microscope of OM) and JSM25800 scanning (the microstructure that SEM) observation analyses laser to become material of alloy of form TA15 titanium quickly, in MH-6 model semi-automatic microscopical what material tested on sclerometer is microscopical hardness. In Chinese spaceflight 159 factories use 3 courtyards numerical control of milling machine of boring of numerical control of TCX110 of planer-type milling machine of numerical control of J243 of company of center of CNC Machining of vertical of XH718/1 3 axes, Italy JOBS 5 axes, Germany four-axle and TK6913A of factory of Kunming machine tool four-axle, choose forging material of TA15 titanium alloy undertook contrast studies machining technical properties. After laser becomes fast figuration of laser of component of alloy of titanium of TA15 of of feature of appearance of form of surface of component of alloy of form TA15 titanium quickly, obtain " close eventually form " semifinished product of titanium alloy part, condition of appearance of its surface form will affect the choice of material of cutting tool of milling rough machining and milling parameter. This task analyses the feature of exterior form appearance that summed up laser to become material of alloy of form TA15 titanium quickly above all, for milling treatment craft is optimized provide guidance. If the graph is shown 1 times, fast figuration chases laser to build receive the scanning, craft characteristic that chases a fused deposit and liquid state metal joint action leaves pulling force of the surface in caky process, the ripple that laser of component of TA15 titanium alloy becomes the surface after form to present a kind of regulation quickly rises and fall " scalelike mark " state body appearance, with forging and cast relatively the exterior form appearance of level off is apparently different. Consider to make clear at the same time, wait for parameter of laser figuration critical process through controlling diameter of laser power, beam of light, quantity sending pink and scanning rate, can adjust monolayer is fused and deposit height and bath form appearance, realize the control of pair of workpiece surface quality thereby, especially of powdery the later and decadent stage of a school of thought gather together gender and light - coupling action result of pink, very apparent to the influence of quality of figuration workpiece surface. Spend when diverge of powdery the later and decadent stage of a school of thought bigger when, was not captured the powder of bath is more, aspersing fall in the process be fused extremely easily partly or agglomeration conglutinate at workpiece sidewall surface (it is a series of isolated and raised oxide horniness via epigenesis of process of follow-up heat treatment grain) (graph 2) . Graph 2 laser become laser of photograph of objective of appearance of form of powder of felt of surface of spare parts of form titanium alloy to become part of form titanium alloy quickly quickly feature of this one special exterior form appearance, to its rough machining has bigger effect. The rough machining craft of component part of plane of alloy of titanium of TA15 of fast to laser figuration considers to make clear, when rough machining first when cutting deepness is less than laser figuration to make an exterior surface roughness, because edge contacts ripple to rise and fall directly layer (relatively hard oxide layer) or grain of exterior felt oxide, cutting tool wears away faster, collapse blade phenomenon happens often, treatment process noise and vibration are bigger. The constituent structure that laser becomes material of uniformity of hardness of alloy of form TA15 titanium quickly is one of main factors that affect machining craft. Graph 3 for laser deposit of edge of alloy of titanium of fast figuration TA15 grows appearance of vertical sectional and macroscopical form, from inside the graph clarity is seen with the surface " scalelike mark " state body appearance chases a fused and deposit trace relative to what answer. Farther times taller microstructure analysis makes clear (graph 4) , laser is had into alloy of form TA15 titanium quickly super- fine " shape of a basket with netting on top " special microstructure, its α piece the layer is petty, piece layer colonies orientaton is random and diversiform, have feature of fast and caky organization, this is the caky organization base that laser has exceedingly good and integrated mechanical property into form titanium alloy quickly. Nextpage pursues 4 laser become hardness of material of photograph of OM of microstructure of model of alloy of form TA15 titanium quickly is one of main factors that affect its cutting to machine craft, vertical,cross section of material of alloy of titanium of fast figuration TA15 mixes laser sectional and microscopical hardness profile is shown 5 times like the graph. Can see, microscopical hardness value distributings to be stabilized equably, for HV350 ～ HV400. Graph 5 laser are fast material of alloy of figuration TA15 titanium is microscopical hardness profile considers to make clear at the same time, different ply test block and edge are different direction, microscopical hardness value all does not have bigger wave motion, result of macroscopical hardness test is similar relatively even stability, for HRC40 ～ HRC44. Laser is fast material of figuration titanium alloy is microscopical hardness thick to the wall, appearance not the uniformity of sensitivity and material interior hardness profile, for follow-up cutting treatment offerred stable advantage. Laser becomes of technical properties of cutting of alloy of form TA15 titanium quickly material of 1 cutting tool and choice of parameter of cutting tool geometry because titanium alloy thermal conductance low, plasticity low, metal is adhesion the liability is big wait for character, very big to influence of cutting tool life, cutting tool material is chosen basically answer from reduce cutting temperature and decrease agglutinant 2 respects set out. Should choose red rigid normally good, bending strength tall, wearability performance of tall, heat conduction is good and the cutting tool data that needs with titanium alloy endophilicity. This task becomes alloy of form TA15 titanium to be versed in construction of model of word bridge plane is an object quickly with laser, contrast considered to differ the cutting effect of cutting tool. The result makes clear, the choice of the cutting tool material that laser becomes cutting of form titanium alloy to machine quickly and parameter of cutting tool geometry is fundamental but the choice circumstance of forging of continue to use, but the appearance of special appearance form of spare parts of alloy of titanium of because laser is fast crash form, in process of layer of milling surface oxidation, can choose tall cobaltic high-speed steel (like W2Mo9Cr4V4Co8) or aluminous high-speed steel (wait for cutting tool material like W6Mo5Cr4V2Al) in order to reduce cost. In laser the milling of component part of plane of alloy of titanium of fast figuration TA15 machines the discovery in research, can wait for a circumstance to undertake repairing grinding to milling cutter according to wear away and discharging bits, change the geometrical parameter of milling cutter, improve cutting to machine function. Use but dislocation cutting tool and milling of hard alloy short-hilted broadsword, the horn before cutting tool of the requirement when rough machining, hind horn wants a little bit small, the horn before cutting tool of the requirement when finish machining, hind horn, helix angle wants a little bit big to slant or tooth is some closer, shorten as far as possible cutting knife is long. The parameter of cutting tool structure that machines laser to become component part of plane of alloy of form TA15 titanium quickly sees a table 1. The option that the choice laser of 2 cutting parameter becomes parameter of cutting of material of alloy of form TA15 titanium quickly and forging are basic and identical, general principle is high cutting rate, medium every tine feed Fz, lesser axial is cut deep Ap and proper big radial cuts deep Ae but, when milling surface layer the requirement is cut greatly deep, rise and fall in order to avoid exterior ripple, grain of felt horniness oxide and layer of horniness of exterior ooze oxygen are right of cutting tool wear away quickly and " hit a knife " collapse blade. Component of short bridge of plane of alloy of titanium of fast figuration TA15 is machining laser if the milling parameter when exterior layer and normal rough machining expresses 2 to show (cutting tool material all is Y330A) . of 3 cutting technical properties is opposite Nextpage the milling of the plane component part that laser becomes bridge of word of labour of alloy of form TA15 titanium, connect, casing to wait for different figure size quickly, boring, auger cut and, the cutting technical properties that laser becomes form titanium alloy quickly and forging titanium alloy comparatives, show good cutting craft stability at the same time. Function of organization of alloy of titanium of this as fast as laser figuration is thick to spare parts appearance, dimension, wall wait not sensitivity is concerned. Consider to discover, laser exists in treatment of cutting of component of alloy of fast figuration titanium the following the characteristic of 2 respects, must notice when making cutting technology. (1) laser becomes component of form titanium alloy to must undertake be underlined meticulously and locating to semifinished product before rough machining quickly, undertake trying a knife when necessary. Because laser is fast,what obtain into form place is already had certain measure precision " close eventually form " semifinished product, mental allowance photograph is gotten lesser than forging much, dimension correlation already was formed between each place at the same time, accordingly, before the requirement is machined external outline and crucial position all undertake comprehensive and meticulous underline, on three-dimensional direction of affirmatory X, Y, Z fiducial, ensure thereby all exterior layers on the spare parts after finish machining (the layer of exterior ooze oxygen that in including the primitive surface that ripple rises and fall and heat treatment course, forms) all can be machined purify. For example, in laser alloy of titanium of fast figuration TA15 some large airlines complex component part (existence is many freely crisscross muscle structure) in machining a process, first rough machining has fixed position with overall dimension only, the result causes individual veins that stand out under the skin a side mental allowance is very big, and the ripple of another side rises and fall after the surface has not machine level off to; is underlined via increasing benchwork and try knife working procedure, optimize adjusted treatment fiducial, make each place all has certain mental allowance. (When 2) becomes component of form titanium alloy to undertake rough machining quickly to laser, first feed should adopt strategy of deepness of relatively big cutting, avoid where a thing can be put to best use namely direct cutting ripple rises and fall grain of oxide of felt of layer, surface and layer of oxygen of heat treatment ooze. Initial stage studies the job is medium, if first feed cuts deep amount lesser, vibratile and acuteness of the noise when rough machining, apparent, and often produce collapse blade phenomenon, cutting tool wears away faster (increase after graph 6(a)); cut deep amount, edge cuts less than of exterior oxidation layer, cutting effect is improved apparently (graph 6(b)) . Graph 6 laser become sketch map of rough machining of layer of surface of alloy of form TA15 titanium quickly 4 laser become quickly cutting of large component part machines plane of alloy of form TA15 titanium 4. 1 milling rough machining is opposite on benchwork platform before rough machining laser figuration " close eventually form " semifinished product undertook lineation, integrated abdomen of this spare parts board lower part each muscle, predestined relationship relative position, and with celiac board upper part the positional correlation of 2 connect concerns, decided treatment is standard, hand-in-hand travel tries a knife, assured the uniformity of mental allowance. With fast purify mental allowance, control as a result of rough machining phase spare parts whole is out of shape for main goal, at the same time the ultrasonic after rough machining of give attention to two or morethings detects requirement (achieve Ra3 like exterior surface roughness.
2, odd side mental allowance ≥ 1.
The) such as 5mm, the craft plan that adopts so is the combination of rate of tall cutting speed, tall feed and small cutting quantity, cut and cut use successive helix and circular arc contrail to undertake as far as possible tangential feed, in order to assure constant cutting condition. The means of high speed treatment such as applied helix becomes alloy of form TA15 titanium to be versed in word bridge undertakes rough machining quickly to laser, acquired better cutting efficiency and exterior quality match, photograph of the objective after rough machining is shown 7 times like the graph. Graph condition of rough machining of bridge of word of labour of alloy of titanium of fast figuration TA15 studies 7 laser to still make clear, in process of high speed rough machining, wanting to consider the following aspects again. (1) uses suitable mill (climb cutting) means, in order to carry cutting condition constant, the of of exterior quality; with be obtained better (2) maintains metallic purify rate is constant walk along of of knife means; reasonably with the choice (3) reduces cutting tool as far as possible cut a number, optional choose loop or mode of single way cutting will undertake arranging mill. 4.
The main demand of finish machining of 2 milling finish machining is to obtain very tall precision, slick spare parts surface, realize the treatment of careful area, wait like small round part, groove. Three-dimensional helix strategy is comprehensive helix treatment and the advantage that wait for tall treatment strategy, can avoid parallel strategy and slant the frequent direction change that appears in strategy of buy finish machining, rose to machine speed thereby, reduced cutting tool to wear away, still can carrying rarely successive and slick cutting tool way is made below the circumstance of the knife. In the light of laser alloy of some large TA15 titanium flies to fast figuration the actual condition that horn of many R circle exists in treatment of cutting of plane component part, drawing style treatment should be used in finish machining. Find the corner that after cutting tool of previous large size is machined, stays and groove above all, take a knife automatically along these corner next, allow to use smaller and smaller cutting tool, agree till the radius photograph of cutting tool radius and three-dimensional corner or groove, reduced the cutting difficulty that corner is in thereby, also reduced the generation of quantity letting a knife and noise. Use strategy of process designing of this finish machining to become alloy of form TA15 titanium quickly to laser some is large " celiac board + muscle structure " plane component part undertakes machining, achieved better result, after finish machining local if pursue,8 are shown. Nextpage pursues 8 laser become of graph of objective of condition of precision work of work of alloy of form TA15 titanium quickly 4.
3 bore hole, travel getting cuts more than 100 Kong Jin that bore diameter, different to differring on workpiece way gets on in CNC Machining center directly after finish machining of bore and tap (graph 9(a)); is next on milling machine of boring of horizontal numerical control symmetrical to 2 or so bearing aperture undertakes boring, the whorl inside the oil filler point that goes up to bearing aperture undertakes the hand moves tap, craft parameter consults basically the treatment craft of forging of BT20 titanium alloy. Graph 9 laser are fast boring of component of alloy of figuration TA15 titanium, auger cut and photograph of the objective after the treatment such as tap detects the result makes clear, treatment hind acquired accurate aperture, Kong Weihe's good aperture surface quality. In machining a process actually, discover at the same time, boring and it is better to get cut stability, of cutting tool wear away degree and forging comparative, did not happen basically to get a phenomenon. 4.
The treatment that the inevitable leftover stress in the treatment process such as milling of component of some large titanium alloy reachs the plane that 4 cutting are out of shape control becomes shape size to amount to 275 Mm of × of 1730mm × 380mm quickly in the light of laser to be brought from this is out of shape, this task is placed from cutting craft, outfit and the many sided such as refrigeration considered to be out of shape control method. Laser becomes thin wall of form titanium alloy quickly / long and thin spare parts and forging the contrast of titanium alloy tries cut craft experiment to make clear, the volume of treatment spring back that laser becomes part of form titanium alloy quickly is relatively minor, but because what study the spare parts has big planar stomach board + odd side differs thick / muscle of gradual change ply asymmetry structure, and spare parts abdomen board flatness demand is very high, this is out of shape to cutting control brought greater difficulty. Above all, undertook optimizing study to cutting craft. Put forward for many times to retroflexion in the light of spare parts of alloy of titanium of this laser figuration, odd the treatment of a few treatment is politic, the any going to realized pair of flatness below condition of stress anneal craft good control in undertaking machining a process, but install clip and bad news of new fixed position to use certain man-hour for many times, and study the process discovers the existence after classics of finish machining spare parts is placed for long is slight be out of shape (stress is released) phenomenon. Accordingly, research increased semifinishing machining and ever since go stress anneal working procedure, make through semifinishing machining final precision work is measured as far as possible small (odd side mental allowance by 2 after former rough machining.
0 ～ 2.
5mm decreases to 0.
5 ～ 1.
0mm) . Subsequently, semifinishing machining close solid undertakes going on the platform holding clip at having datum plane stress anneal, the result makes clear, increase semifinishing machining and ever since go after stress anneal working procedure, the flatness control effect of the spare parts after final precision work is much better, did not discover when flatness of spare parts of the remeasure after be being placed for long be out of shape apparently, the leftover stress level in showing via optimizing the cutting after working procedure craft reduced a hardware greatly, be helpful for be out of shape control. Next, to holding clip means undertook optimizing. Consider to make clear, clamping apparatus should have enough tigidity, the clamping force when workpiece is being installed shoulds not be too big, the vibration of the spare parts when be being machined in order to decrease or be out of shape. In addition, titanium alloy coefficient of thermal conductivity is small, the heat in metal cutting of the generation in process of cutting titanium alloy is accumulated at cutting blade around send out not easily, cause cutting tool to wear away surface roughness of surface of serious, treatment is low bring about a spare parts badly even to be burned too, because must be opposite in this cutting process,machine a spare parts sufficient and pouring cutting fluid. Laser becomes the cutting refrigeration of spare parts of form titanium alloy to do not have characteristic quickly, the result when choosing HGS-113 cutting fluid to undertake to component of this large titanium alloy cutting is machined is favorable. Conclusion (1) laser becomes alloy of form TA15 titanium quickly " close eventually form " workpiece surface has regular ripple to rise and fall " scalelike mark " feature of state body appearance, requirement rough machining uses this kind of special exterior form appearance to cut deep amount greatly appropriately when exterior layer. (2) laser asks to undertake lineation fixed position meticulously before rough machining of spare parts of alloy of fast figuration titanium, should try a knife when necessary, have appropriate mental allowance in order to make sure each place all stays. Because laser becomes body work to already had certain measure precision quickly, stronger dimension correlation was formed to concern between each place. (The milling that 3) laser becomes alloy of form TA15 titanium quickly, boring, auger cut and the cutting technical properties such as tap and forging are not had showing difference, craft of the choice that its machine cutting tool material and parameter of cutting tool geometry, cutting, refrigeration and outfit clip outside dividing afore-mentioned 2 respects characteristic can consult basically forging. (4) uses optimized cutting technology component part of plane of alloy of some large TA15 titanium had fast to laser take shape milling rough machining and finish machining, bore hole, bore and tap, acquired good dimension precision and exterior quality. CNC Milling
