Cubic nitrogen changes boron to get together the development of brilliant material and promotion

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1. Foreword  is in manufacturing industry of fittings of car cylinder bushing, roller, mine, wear-resisting is cast-iron, hard cast steel there is the following problem since treatment is long-term: Hard alloy razor blade can bear only inferior cutting speed, cannot machine the cast of 58HRC above; Razor blade of pottery and porcelain can bear in thick car 10 meters of cutting speed of the left and right sides, but in encountering slag inclusion, trachoma or the treatment in impeller of pump of broken bits oar, often appear bit disintegrate phenomenon; Of razor blade of pottery and porcelain fight concussion tenacity to be not had bear the rough machining requirement of hard cast, the treatment of the tall Gr cast of above of insufficient hardness 65HRC. With getting together brilliant nitrogen changes boron (CBN) exceed strong cutting tool for what material makes, it is implementation cast-iron with hard steel (45HRC above) the first selection cutting tool that efficient, high quality machines, but in be being produced actually, because CBN cutting tool uses copper or silver-colored solder to solder more, its solder function and intensity cannot satisfy the heat-resisting of place to be cut greatly deep (＞ 5mm) , the requirement of heavy cut or interrupted cutting, cannot use in these trade promotion.  2. Tall tenacity gets together the development  that brilliant nitrogen turns material of boracic cutting tool with CBN microcrystalline for main material, join bond to mix even, through the mould suppress becomes the figure of a need, next agglomeration, this is preparation those who do not have hard alloy base is pure get together the necessary measure that brilliant nitrogen turns boron.  is in real development, of bond choose crucial: ① bond is due taller thermal stability, because the temperature in the process is used to amount to 600 ℃ above in bit; The chemistry with ② bond and nitrogen or boracic due and strong element adds up to a gender in person; ③ falls in high temperature condition, bond and be not answered to produce chemistry to close in person by the alloying element in treatment workpiece; ④ gets together when brilliant nitrogen changes boron to be used at processing different metallic data, if wear-resisting is cast-iron with quench steel, the content of its bond is very big to cutting effect impact, accordingly, the CBN with production bond high content gets together when brilliant, bond should have taller hardness and tenacity.  gets together in development in the course that brilliant nitrogen changes boron, choose pottery and porcelain of microcrystalline nitride, boride, carbide to be bond, be like: TiC, AlN, TiN or Al2O3. This kind of bond has the property of high temperature resistant, tall wear-resisting, at present the razor blade of pottery and porcelain on the market uses this kind of material to serve as basic raw material mostly. After  microcrystalline CBN adds bond, should mix with bond even rear can use. Get together the preparation of brilliant CBN is to those who finish is in below condition of extrahigh voltage, high temperature -- also fall in such condition only, ability comes true: ① CBN is microcrystalline between 2 polymerization, form get together brilliant CBN framework; Reach between ② bond oneself agglomeration undertakes between bond and CBN.  development gets together the requirement that adopts when brilliant CBN razor blade is: Pressure 6 ～ 6.

5GPa, temperature 1600 ℃ of 1500 ℃ ～ , agglomeration time 1 ～ 2 minutes. Be aimed at what treatment of vehicle of wide choice of tall Gr cast-iron material uses to get together brilliant CBN razor blade, bond content is in 20% the following, trade name calls BN-S.  3. The use of BN-S razor blade popularizes  above all preparation 12.

7 × 12.

7 × 4.

The quadrate razor blade of 8mm norms, use at the treatment of jacket of pump of broken bits oar, fender, impeller, be aimed at the problem that in machining a process, appears, summed up a few cutting parameter and use experience.  (parameter of 1) razor blade: R1 of circular arc of point of a knife.

0 ～ 1.

2mm, lose edge 150 ° of 10 ～ × 0.

1 ～ 0.

2mm, negative point of view pouring arris and width are very apparent to the influence of cutting effect;  (2) cutting parameter: The horn before cutting is lost 80 ° of 6 ° ～ , this also is the point of view that bit forms after arbor jacket is placed. Be compared and character, razor blade of pottery and porcelain uses 15 ～ however below similar treatment requirement the before losing horn of 200 ° . It is BN-S razor blade below when tall Gr of treatment 55HRC above is cast-iron, the treatment parameter that chooses actually: Parameter of  rough machining: 65 ～ of V ＝ 90m/min, f ＝ 0.

12 ～ 0.

18mm/rev, 5 ～ of Ap ＝ 10mm; Finish machining parameter: 80 ～ of V ＝ 120m/min, f ＝ 0.

2 ～ 0.

3mm/rev, ap ≤ 5mm. By treatment material hardness taller, or machine tool tigidity is poorer, or when interrupted cutting is more serious, inside the cutting parameter limits of above, choose inferior treatment parameter to be able to prolong bit life.  (3) cutting phenomenon: BN - when tall Gr of treatment of S razor blade is cast-iron, bits is cut to show shoot when new razor blade begins to use drossy, 10 ～ after 15 minutes, edge has minim to wear away, begin to appear cut bits to spin phenomenon, in the meantime, the color that cuts bits becomes shallow blue by golden color or blue-black, the process of bit treatment workpiece turns by dinkum cutting for cutting and crowded cut coexistence, when this and razor blade of pottery and porcelain process this kind of work pure crowded cut a phenomenon to differ. Use BN - when S razor blade is machined, sound is ringing, add the grating noise of man-hour without razor blade of pottery and porcelain.  (4) the requirement to arbor: BN - S razor blade is in high speed cutting (dry cut) when, cutting blade or whole bit show fiery scene, the temperature of arbor is fast and elevatory, and the temperature of workpiece rises slower. Treatment ends, contrast uses the case of razor blade of pottery and porcelain, use BN - the workpiece temperature of S razor blade is low and arbor temperature is high. In be being used actually, if did not take compulsive cooling step to arbor, after thick car machines 25 ～ 35 minutes continuously, arbor can appear phenomenon of high temperature bate, should stop in time to machine, change arbor. It is to use BN below - the example of jacket of pump of oar of broken bits of treatment of S razor blade: Bit norms: SNMN120412; Arbor dimension: 150 × of tall ＝ of long × wide × 30 × 35 (Mm) ; What use a machine tool: 2.

5 meters establish a car; By treatment material and its hardness: A31 (the prep above that contain Gr 25% ) , HRC68 ～ 70; Machine a condition: Cast thick car, treatment layer depth is differ, and contain slag inclusion, trachoma to wait cast blemish; Cutting parameter: V ＝ 90m/min, f ＝ 0.

15mm/rev, ap ≤ 10mm; Result: 7 minutes of finishing treatment when using, bit uses observation of 50 times magnifier, where a thing can be put to best use is only and little wear away, without collapse blade.  4. Epilogue  passes BN - the use situation that S razor blade produces enterprise and company of production of pump of oar of professional broken bits in roller of alloy of major tall Gr, can reach the following conclusion: ① can raise cutting rate greatly, realize true high speed cutting; When ② is machined in the light of the interrupted cutting of material of tall hardness tall wear-resisting, gravity, bit does not have disintegrate phenomenon, suit intermittent treatment; ③ doing cuts free from contamination, cutting does not have noise, realized environmental protection production; ④ and photograph of razor blade of pottery and porcelain are compared, service life is longer, treatment efficiency is taller, finished cost is consequently lower, market application perspective is relatively wide. CNC Milling CNC Machining