Aperture of abnormity of workpiece of alloy of nickel radical high temperature machines the research of craft

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Summary: According to aviation engine aperture of the abnormity on eddy turntable writtens guarantee form is complex the characteristic that reachs difficult treatment of material of alloy of nickel radical high temperature, use auger cut, the different combination of milling and grinding craft, chose new-style coating cutting tool and corresponding cutting parameter to undertake craft experiments. Connect those who cross the cutting tool in assaying process, emery wheel to wear away (damaged) circumstance and its are right the influence of precision of labour of abnormity Kong Jia and exterior surface roughness, discussed milling, grinding to machine the feasibility of aperture of abnormity of turntable of eddy of alloy of nickel radical high temperature. Study the result makes clear, through optimizing treatment parameter, aperture of eddy turntable abnormity gets craft of the milling that cut → to be able to replace commonly used electric spark effectively to machine craft. 1 foreword alloy of nickel radical high temperature (wait like In718, Waspaloy) have thermal stability intensity of good, high temperature and hardness are tall, anti-corrosive, fight wear away wait for a characteristic, it is typical difficult treatment material, commonly used wait for engine key component at making eddy rotary table. Because eddy turntable is one of crucial parts of aviation engine, produce fatigue invalidation easily below stress, temperature and harsh working ambient conditions, because material of this eddy turntable is reached,making a technology is the key that develops high-powered aviation engine. As a result of the abnormity on eddy turntable Kong Youre does circular arc and linear composition, form is complex, the requirement when treatment forms paragraph of place each accurate, transfer pliable and do not produce treatment turn trace, exterior surface roughness accords with craft requirement, because the treatment of aperture of abnormity of alloy of this this high temperature is the difficulty of eddy turntable treatment. Current, aviation engine manufacturer all uses electric spark to machine a method to machine aperture of abnormity of alloy of nickel chromic heat-resisting, but the hot influence layer that electric spark produces in treatment process uses purify of common grinding, abrade method hard, often need to wait for special technology purify to should deteriorate with abrasive efflux layer, treatment efficiency is low, manufacturing cost is high. Accordingly, to the abnormity of alloy of nickel radical high temperature of efficient low cost Kong Jia is versed in methodological research more and more be taken seriously by the height of people. The article is cut through getting, the different combination of milling and grinding craft, technology that chooses new-style coating cutting tool and proper treatment parameter to machine aperture of abnormity of alloy of nickel radical high temperature experiments, discussed to replace electric spark method to machine the feasibility of aperture of abnormity of alloy of nickel radical high temperature with milling and grinding treatment method. 2 craft experiment and assaying condition cutting experiment to undertake on machining center, be seen pursue by the appearance of treatment abnormity aperture and dimension 1: Of abnormity aperture sectional comprise point-blank with 2 paragraphs by 6 paragraphs of circular arc, hole depth 10mm. The following technology uses respectively in the experiment: ① getting cuts hole of abnormity of milling of → of Ø6mm round hole; ② getting cuts hole of abnormity of grinding of → of Ø6mm round hole; ③ getting cuts hole of abnormity of grinding of → of aperture of abnormity of milling of → of Ø6mm round hole. Parameter of the treatment condition of 3 kinds of different process, craft sees a table 1. Express speed of cutting of parameter of cutting of cutting tool of 1 working procedure (M/min) feed (Mm/min) cutting deepness (Mm) getting cuts ↓ milling to get cut 1Ø4mm of hole milling of milling of 2258- of broach of coating of Ø6mm hard alloy multilayer PVD coating is globose milling cutter, 2 blade, blade grows 25mm, 100mm of milling cutter overall length, petiole diameter Ø6mm, straight handle 523330.

1 hole milling 2104666 get the grinding that cut ↓ those who cut Ø4mm of diameter of grinding of 2258- of broach of coating of Ø6mm hard alloy, long 6mm is cylindrical alumina emery wheel (chromic corundum) , grade RA120, petiole diameter Ø3mm1883330.

05 get grinding of ↓ of the milling that cut ↓ cut mill of milling of 2258- of broach of coating of Ø6mm hard alloy to grind aperture 1Ø4mm multilayer (TiAlN, tiCN, tiN)PVD coating is globose milling cutter, 2 blade, blade grows 25mm, 100mm of milling cutter overall length, petiole diameter Ø6mm, straight handle 523330.

1 mill grinds aperture those who grow 6mm is Ø4mm of 2104666 grinding diameter, cylindrical alumina emery wheel (chromic corundum) , grade RA120, petiole diameter Ø3mm1883330.

05 workpiece material: Cooling fluid of alloy of high temperature of In718 nickel radical: Chroma is the emulsion of 9% , pressure 30Bar pursues the sectional appearance of 1 abnormity aperture and dimension graph aperture surface surface roughness uses the 2 abnormity that use different technology to obtain respectively tool microscope and image collect what the system measures milling cutter and emery wheel to wear away, the record wears away form appearance. The exterior surface roughness that with surface roughness of Taylor-HobsonSurtronic 3p surface the axes direction of aperture of appearance edge abnormity measures aperture Ra. The surface roughness of abnormity aperture surface that result and analysis obtain to machining process 3 kinds undertakes contrast, the result shows 2 times like the graph: In 3 kinds of process, use get grinding of → of the milling that cut → (auger cut low dosage of → of treatment Ø6mm round hole aperture of abnormity of grinding of → of aperture of milling treatment abnormity) the exterior surface roughness of the abnormity hole that craft place scores is the smallest, and get the grinding that cut → (auger cut hole of abnormity of grinding of → of treatment Ø6mm round hole) the surface roughness of abnormity aperture surface that craft place obtains is the biggest. The experiment proves: Milling treatment is used to also can score the abnormity hole that contented surface surface roughness asks below this experiment condition; The precision of surface roughness of abnormity aperture surface that treatment of the milling after treatment of the grinding after bore compares bore obtains is low; Treatment of grinding of travel of the reentry after milling can be on certain level the precision of exterior surface roughness that improves abnormity aperture treatment, but can raise cost, reduce efficiency. The milling cutter below different treatment condition wears away and damaged circumstance: In getting course of the milling that cut → , milling after an aperture, the corner office of two milling cutter all produced serious groove to wear away with damaged. Use low cutting dosage when milling abnormity aperture (V=52m/min, f=333mm/min) , the damaged with milling cutter more apparent generation (3a) seeing a picture; And with tall cutting dosage when milling abnormity aperture (V=104m/min, f=666mm/min) , the groove of milling cutter wears away more remarkable (3b) seeing a picture. (A) milling aperture the milling cutter of 1 (B) milling aperture the milling cutter of 2 pursues of 3 milling cutter wear away, damaged form appearance (milling after an aperture) as a result of In718 nickel alloy is in Jigaowen treatment of extremely easy generation is sclerotic in cutting treatment, the horniness photograph such as photograph of aggrandizement of the G in alloy, G" and WC, WN is below high temperature still maintaining tall hardness and high speed cuts the knife face that changes cutting tool and where a thing can be put to best use, bring about cutting tool to produce groove to wear away. In addition, alloy of nickel radical high temperature produces side direction plasticity extremely easily when cutting to flow and the dentate Mao Bian that cut bits and workpiece flash produce in cutting tool point. Cutting tool of Mao Bian and these flash high speed, high frequency concussion, cutting tool is brought about to arise below action of periodic thermal stress tiny flaw and flake. And undertaking tall dosage when milling, the high temperature that cutting area produces brings about milling cutter to wear away badly with damaged, increased the treatment surface surface roughness of abnormity aperture. From the experiment knowable: When employing alloy of high temperature of nickel radical of In718 of grinding of alumina emery wheel, emery wheel wears away quickly, grinding after an abnormity aperture, emery wheel becomes conic entity, the surface has serious bur (4) seeing a picture. Because grinding has temperature of grinding muscularity, grinding when alloy of nickel radical high temperature,this is advanced characteristic, fall to strength effect in higher grinding temperature and older law, the material be grindinged of grinding area produces serious plasticity to be out of shape and conglutinate is wearing a face, and this kind is out of shape and conglutinate brings about grinding force to increase further, fall off below the action of shearing force as bur, make emery wheel grinds bead happening to damaged falls off even and lose cutting ability prematurely, cause workpiece surface surface roughness to increase (the) of workpiece surface surface roughness that is more than milling treatment even. The place on put together is narrated, the treatment efficiency that according to machining In718 nickel to 3 kinds of afore-mentioned craft Jigaowen adds up to aperture of golden workpiece abnormity and the trade off study that machine the effect, with getting the milling that cut → to machine craft to replace electric spark law to machine aperture of abnormity of workpiece of alloy of nickel radical high temperature is feasible. Graph 4 grinding of the emery wheel after an abnormity aperture wear away form appearance pursues 5 be machined sketch map of workpiece abnormity aperture 3 get the milling that cut → to machine nickel alloy abnormity aperture machines Jigaowen with detect workpiece and material: Workpiece material is alloy of Waspaloy nickel chromic high temperature (hardness 38HRC) , bases sees a table 2. The content of NiCrAlTiFeZrMoCoCB of chemical composition element that expresses alloy of chromic high temperature of 2 Waspaloy nickel (Wt.

%)5719.

51.

4310.

74.

3130.

050.

The abnormity aperture on 01 eddy turntable is the 15 ° inclined hole that deepness is 19mm, aperture coping is dambered surface. When milling experiments, for the treatment process of aperture of the abnormity on imitate eddy turntable, test specimen treatment becomes the dambered surface that becomes 15 ° rake with underside, hole depth 19mm(sees graph 5) , 5 workpiece are group of a test. Treatment and detect: Abnormity aperture machines working procedure to include: Aperture of center of ① mill Ø6mm is planar; ② getting cuts the round hole that machines Ø6mm; Aperture of abnormity of ③ milling treatment (treatment condition sees watch 3) . Measure milling cutter to wear away with surface roughness of abnormity aperture surface; Use 3 coordinate measuring instrument (the diameter that measure a head is in respectively for Ø2mm) the size that the position of hole depth 3mm, 6mm, 9mm, 12mm and 15mm measures abnormity aperture and outline change; Survey test group what with the last abnormity aperture machines the surface the first is microscopical hardness, so that have abnormity opening,machine the research of sclerotic degree. Watch 3 get the milling that cut → to machine a condition to machine time of cutting of parameter of cutting of working procedure cutting tool (Min/ aperture) cutting speed (M/min) feed (Mm/min) cutting deepness (milling cutter of hard alloy of Ø6mm of face of Kong Ping of center of Mm) mill Ø6mm 184731.

3 auger cut 1847-0 of broach of coating of hard alloy of Ø6mm aperture Ø6mm.

Ø4mm of aperture of 63 milling abnormity is multilayer PVD coating (TiAlN, tiCN, tiN) carries milling cutter, 2 blade, blade grows 19mm, 75mm of milling cutter overall length, petiole Ø6mm, straight handle 252000.

17.

58 cooling fluid: Chroma the emulsion of 9% , result of pressure 30Bar test and discussion geometry precision measure the measurement of machine according to 3 coordinate result (show) 6 times like the graph, the direction of deepness of axial of edge of size of all abnormity hole that milling machines is reduced, the axial of abnormity aperture shows taper, the biggest taper is 0.

19 ° , the specification follows milling cutter to wear away in the dimension of aperture of abnormity of direction of X, Y and reduce apparently. (A) X direction (B) Y direction pursues the abnormity opening that 6 milling machine is effective dimension contrasts public errand of size of hole of the D of some company abnormity (X direction: 7.

65 ～ 8.

25mm; Y direction: 6.

35 ～ 6.

85mm) , the size variation of 5 aperture all is in milling test group in limits of this public errand, accord with treatment precision requirement. Exterior surface roughness is shown 7 times like the graph, ra and Rz are in the surface roughness of abnormity aperture surface that uses treatment of milling cutter of 2 blade coating respectively 0.

30 ～ 0.

40µm and 2.

3 ～ 3.

Change inside 64µm limits; The addition that lets milling time namely milling cutter tatty is increased, rz shows workpiece surface surface roughness increscent current. This shows, if use milling cutter of hard alloy of 4 blade coating, optimize milling parameter to wear away in order to reduce cutting tool further at the same time, be expected to score the abnormity hole that contented surface surface roughness asks directly, working procedure of precision work of leave out sequel, reduce cost, improve treatment efficiency. Treatment surface is microscopical hardness pursues the first with the last aperture treatment surface in the 8 5 abnormity aperture that are milling of same milling cutter is microscopical the metabolic circumstance of hardness. If the graph is shown 8 times, two abnormity aperture all appeared to machine phenomenon of surface layer bate (ply is 60µm) about, its are microscopical hardness even under matrix hardness. As second surface layer microscopical the addition of hardness, achieve when deepness when making an appointment with 140µm ～ 180µm, matrix hardness restores. The plasticity of the surface layer of treatment of alloy of nickel radical high temperature that phenomenon of surface layer bate may differ with thermal conductivity is out of shape big, temperature is high about. As milling cutter wear away, cutting area temperature is elevatory, abnormity aperture is machined exterior bate, sclerotic phenomenon is more apparent. Graph the relation of surface roughness of surface of 7 abnormity aperture and milling time pursues surface of treatment of 8 abnormity aperture is microscopical the efficiency of metabolic milling treatment of hardness is below this experiment condition (3) seeing a table, plane of center of milling abnormity aperture, auger cut abnormity of central aperture and milling the handling time of Kong Sandao working procedure is respectively 1.

3min, 0.

63min and 7.

58min, increase milling abnormity opening the man-hour that two upright circular arc pour wine cup, the total handling time of an abnormity aperture is 17 minutes about. And used electric spark and abrasive efflux in the past the part with same treatment of two working procedure, floor-to-floor time is 40min and 6min about respectively, total man-hour is 46 minutes. The course is comparative, the milling that this experiment uses machines craft to be able to reduce the handling time of 58% , and all working procedure can install clip to finish last time in machining center, auxiliary time is little, save total man-hour greatly. Because milling processes the data of a generation degenerative layer ply is far the burn layer ply that is less than electric spark to machine a generation, although abrasive water efflux increases to machine working procedure to machine exterior integrality in order to rise after milling machines working procedure, the man-hour that also can make abrasive water efflux is machined shortens greatly. 4 conclusion pass the treatment craft experiment of aperture of eddy turntable abnormity to contrast, use auger cut → low dosage the surface roughness of abnormity aperture surface that place of craft of milling → grinding obtains is the smallest, and the surface roughness of abnormity aperture surface that gets treatment of craft of the grinding that cut → is the biggest. Use the abnormity Kong Ke that gets craft of the milling that cut → to machine turntable of eddy of alloy of nickel radical high temperature to satisfy workpiece geometry precision and requirement of exterior surface roughness; With use photograph of craft of efflux of abrasive of electric spark → to compare, can reduce handling time significantly. Below the premise that assures to machine precision, through optimizing cutting parameter, can rise further use the treatment efficiency that gets technology of the milling that cut → . CNC Milling