The diamond on hard alloy velar deposit

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Deposit of chemical on hard alloy gas phase (the tool of diamond film coating of CVD) has shown wonderful industrial application prospect. But, the combinative strength between the diamond film that the barrier of the oldest technique that material of this kind of tool uses is a deposit and hard alloy matrix is too low. Main reason depends on: ① has difference between hot coefficient of expansion (the hot coefficient of expansion of WC is ~ of 4 × 10-6 6.

℃ of 2 × 10-6/ , the hot coefficient of expansion of diamond is 1.

~ of 2 × 10-6 4.

) of ℃ of 5 × 10-6/ . ② C is in the dissolvability in matrix Co is very big. ③ C is in the diffusion coefficient in matrix Co is taller. Two elements are in what can promote black lead after below CVD diamond condition grow, the form nucleus that disturbs diamond and grown, caused finite diamond form nucleus and black lead deposit. If enough diamond form nucleus can make successive diamond film, but the black lead photograph that is not conglutinate because of the existence between matrix and diamond film, the interface is destroyed, diamond film always flakes instantly from matrix. The reaction between the C in the Co in matrix surface and deposit gas source is diamond film conglutinate the obstacle of the oldest technique on hard alloy cutting tool. The key that enhances conglutinate is to carry away the Co of matrix surface or restrain its active or motility. The common method that solves this problem is the Co amount that in reducing whole cutting tool, contains, or in cutting tool apparently bring to bear on one intermediate layer. But Co union provides strength to cutting tool, whole of content of cutting tool Co drops the stand or fall that the influence its cutting function exerts. And bring to bear on between matrix and diamond film the combinative performance that appropriate intermediate layer can improve meantime significantly. The article summed up what raising place of field of strength of the union between diamond film and hard alloy matrix to undertake at present all sorts of research, include matrix of preparation fine brilliant, undertake pre-treatment to matrix, optimize the craft condition of CVD diamond film, and bring to bear on between matrix and diamond film transfer the layer, and to the deposit on hard alloy the research foreground of diamond film undertook discussing, with period for diamond film the application of cutting tool lays certain foundation. 1 base material and KUNIO SHIBUKI of its pre-treatment base material point out, the WC in WC-Co particle size has certain effect to diamond form nucleus. Diamond handles deposit in WC grain border easily, finer, dimension jumps over WC grain small, the form nucleus density of diamond is bigger, the conglutinate of diamond film is better. 32 when if when WC particle size is made an appointment with,be 1µm, the form nucleus density of diamond film is 9 × 106cm-2, and when WC particle size is about 0.

When 5µm, the form nucleus density of diamond film is 5 × 107cm-2. Graph 1 go the deposit diamond film surface on hard alloy matrix goes to carbon Co handles deposit of chemical on hard alloy matrix gas phase when diamond film, what go against diamond film as a result of Co is deposit and must the surface goes Co. KUNIO SHIBUKI points out, the hole volume that Co carries away from WC-Co matrix surface and generates in the surface has certain effect to the conglutinate intensity of diamond film. Mix when hole size when diamond particle size is almost same, the conglutinate intensity of diamond film is best, when cutting Al-10%Si alloy, diamond film of hard alloy razor blade hind knife face wears away dinky. With nitric acid solution (HNO3:H2O=1:1) after 10min of dip corrode matrix, can make matrix surface contains Co quantity to drop 0.

2%[9] . M.

A.

Taher uses 1500 eye corundum first to WC-6%Co and WC-22%Co matrix paper is abrade, be in next nitric acid solution (HNO3:H2O=1:3) in the chemical 10min that engrave corrode the Co with purify matrix surface, undertake to matrix ultrasonic is handled again next (diamond particle size is less than 0.

1µm handles 3min)[10] . Chart of its energy scattering (EDS) test shows the surface contains Co quantity to be less than as a result 1% . To the surface the quantity that contain Co is less than the matrix of 1% , co is reached to the form nucleus of diamond grow to had done not have an influence, right now the form nucleus density of diamond is 108cm-2 about. Still point out in article should make diamond film gains higher conglutinate strength, the surface roughness of matrix surface should lie in certain limits (Ra=0.

06 ~ 0.

25µm) . IO.

SAITO points out, with 2.

5%CO-H2 plasma engraves corrode to drop the Co of WC-Co surface optionally, it is in Co chroma 10% when the diamond film of preparation has best quality, its conglutinate intensity is 1.

7kgfmm-2, diamond pyramid hardness is 8500kgfmm-2. M.

The person such as MURAKAWA splashs the Co that shoots surface of quarter corrode WC-Co with Ar ion, make contain Co quantity to fall to 0.

8% , because Ar ion is right,this is of Co and WC splash firing rate rate to differ a lot of, its splash those who shoot rate to compare is 5:1 about. The person such as Li Chengming uses the method of pretreatment of irradiation of accurate element laser to hard alloy matrix, the vast difference that uses Co and WC melting point to go up (WC melting point is 2800 ℃ , co melting point is 1495 ℃ ) , use high-energy laser bundle the Co that the alternative evaporate fit of generation uses layer of surface of purify YG6 hard alloy, use action of laser surface modified to make hard alloy surface rough at the same time change, produce a hammer to plunge into effect to diamond film thereby, and achieve enhance the combinative strength between diamond film and matrix further. The surface goes C handles the WC matrix to hot pressing agglomeration, go with 2%O2-H2 plasma first carbon, subsequently reoccupy diamond grain undertakes to the surface thick change, use MWPCVD law deposit finally diamond film, if pursue,1 is shown. 2%O2-H2 plasma engraves surface of corrode WC matrix, make WC goes C is W, w is when diamond deposit complete carbonization, make extremely fine WC grain (dimension is 10 ~ 100nm) about. Among them of WC go the carbonization process of carbon and W to intensity of diamond film conglutinate it is important to raise a move action, because the interface between diamond film and extremely fine WC grain accumulates increasing reason,this is. From the graph 1 in can see, the fine WC grain of matrix invades diamond film in. Because invade the wedge effect of WC grain, raised the conglutinate of diamond film thereby. The sort of source of craft condition gas of 2 CVD diamond film is amiable body chroma M.

A.

When the person such as Taher studied CH4 chroma changes (1% , 3% , 5% , 7% , the deposit of 9%) diamond film. The result makes clear, deposit diamond film grain has particular concern between dimension and CH4 chroma, it is when CH4 chroma 0.

5% ~ 1% when, diamond grain dimension is 1% ~ when CH4 chroma for 5 ~ 11µm; 4% when, diamond grain dimension is 11 ~ 60µm. CH4 chroma is 3% when deposit diamond film the mechanical function of hard alloy razor blade is optimal. IO.

The person such as SAITO studied the influence with CO deposit to diamond film chroma points out, it is in CO chroma 10% when the diamond film of preparation has best quality, its conglutinate intensity is 1.

7kgfmm-2, diamond pyramid hardness is 8500kgfmm-2. And it is in CO chroma 5% when the intensity of diamond film conglutinate of preparation is 0.

5kgfmm-2, diamond pyramid hardness is for 10000kgfmm-2;CO chroma 50% when the conglutinate intensity of the diamond film of preparation is 2.

5kgfmm-2, diamond pyramid hardness is 4000kgfmm-2. M.

The person such as MURAKAWA points out, with HFCVD law, it is carbolic source with alcohol, to hard alloy matrix need not undertake special pre-treatment, can obtain the diamond film layer with good quality on the WC alloy of rich Co. And, with this diamond velar cutting tool is used at cutting thick 2.

The aluminium of 5mm board when, in punching 5 × 104 hind, did not discover to have on diamond film on cusp of point of a knife the conglutinate that wear bead and be cut the phenomenon of material fragment conglutinate. The person such as deposit temperature KUNIO SHIBUKI points out, the conglutinate intensity of diamond film increases along with the accretion of deposit temperature, the result sees next tables. When cutting Al-10%Si alloy, diamond film of hard alloy razor blade hind knife face wears away dinky. Watch diamond particle size / of hole size and conglutinate intensity and particle size of deposit temperature diamond and hole size it is OK and OK that than conglutinate intensity 1000 ℃ <1 differs 900 ℃ of 800 ℃ 1 can well > 1 difference is very OK 3 bring to bear on transfer the layer is between WC-Co and diamond film deposit one intermediate layer, diffuse what intermediate layer serves as C or Co obstacle layer, the issue with the combinative too small strength between the diamond film that solves a deposit thereby and hard alloy matrix. Because intermediate layer is mixed,the distinct possibility of hot coefficient of expansion between diamond film compensates its interface stress and velar stress. The compound that foregoing research are a Si regards diamond deposit as the intermediate layer on WC-Co. J.

M.

The person such as Albella is multilayer to the one diamond that develops on hard alloy matrix velar structure is WC-8%Co/B/TiB2/B/ diamond, among them when B/TiB2/B total ply is less than 1µm (thin B layer, 0.

6µmTiB2, ) of thin B layer, the conglutinate of diamond film is best. The goal of every part in intermediate layer is different: The Co of the B layer with first ① and surface of hard alloy cutting tool reacts, generated Co2B and CoB. Accordingly, deposit ground floor B is the significant step of the active that reduces Co of surface of hard alloy cutting tool and motility. ② next, go up in ground floor B or the deposit on boride layer a TiB2. To TiB2, coB is in thermodynamic going up is stability, base material can strengthen the tie between Co2B and CoB2 and TiB2 without B apparently. The action of TiB2 depends on regarding as diffuse obstacle layer is mixed with detached C Co. The B layer with last ③ enhanced diamond the conglutinate to TiB2. Mix than TiB2 between B and TiB2 and B and diamond the chemical reaction between diamond is much. In addition, b because with amorphous formal deposit, can regard all force as absorbefacient. Still point out in article, monolayer B or monolayer TiB2 are increasing diamond form nucleus is effective on density, but the conglutinate that does not improve diamond film. J.

M.

The person such as Albella develops to increasing the combinative strength between diamond film and hard alloy matrix another multilayer velar structure, its process has 3 situations: ① CVD is not successive diamond nucleus one layer; ② electrodeposit a Ni, action lives to secure first deposit the diamond nucleus on matrix, make Ni fills the whole gap of diamond; ③ CVD diamond film; Its structure is shown 2 times like the graph. Graph 2 multilayer velar structure sketch map 4 look into improvement the research of conglutinate intensity of film basically centers the diamond on hard alloy in the following respects: ① chooses proper base material. The pre-treatment of ② matrix surface, concentration is in make the surface produces macroscopical limitation, in exterior gush plating kind of the brilliant seed of diamond structure and matrix go carbon goes cobaltic processing. ③ optimizes velar technology condition. ④ brings to bear on between matrix and diamond film transfer layer. These a few respects are on certain level to increasing the conglutinate strength of diamond film it is effective, but up to now, return what did not discover essential sex to settle way. The research of face of the tripartite before people is right had made many works, but about transfer the research that layer improvement combines function between matrix and diamond film just just starts. Consider chemical gas phase is deposit on cutting tool base material (the conglutinate intensity of CVD) diamond film is inferior, and the combinative function between metallic Mo and diamond film is very good, the author puts forward to use multilayer velar structure, namely hard alloy matrix / Ni-Mo electrodeposit layer / Ni-Mo- diamond grain (bead diameter is controlled in a few micron) compound electrodeposit layer / deposit of chemical gas phase diamond film. Introduce Ni-Mo deposit layer and Ni-Mo- diamond the layer regards compound electrodeposit as the combinative function that the intermediate layer between diamond film and hard alloy matrix will come to to improve meantime. Because contain the deposit layer of Mo, can make diamond rises greatly in the nucleate density of matrix surface, and the affiliation of diamond grain, can make diamond obtains several coessential extension to grow in matrix surface small area, increase the combinative strength of meantime thereby. Current, this research is undertaking in. CNC Milling CNC Machining