The influence of boracic pretreatment of ooze of underlay of smooth hard alloy to function of CVD diamond film

034µm. Ooze boracic pretreatment uses solid ooze boracic method, ooze is boracic exhaust of mandarin orange of high temperature of type of the heat outside using, heat use Tie Ge aluminous heat, crucible uses 4 ～ 6mm1Cr18Ni9Ti to be able to bear or endure corrode stainless steel board make, use double deck cover board to assure its sealing. Different ooze boracic agent was used to undertake comparative an experiment in ooze boron. Destroy sample surface to prevent bright and clean degree, after underlay passes ooze boracic pretreatment, did not undertake any thick change abrade namely deposit diamond is filmy. Experiment parameter sees a table 1. Express parameter of experiment of 1 ooze boracic pretreatment the article uses film of diamond of deposit of heater CVD law, the reaction gas that CVD diamond film experiments is mixed for acetone hydric, the bulk mark of acetone is 1% , reaction pressure is 5.

32kPa, hot filament is tantalum silk, exterior temperature makes an appointment with 2200 ℃ , drift 0.

1 ～ 0.

3A, underlay surface temperature 900 ℃ of 750 ～ . Two filament and underlay parallel are decorated, filament span 22mm, underlay is in in the middle of. Deposit time is 4 ～ 5h. The exterior form appearance of the constituent composition after the ooze boron effect that appearance observes the X ray diffraction that adopts S530SEM scanning electron microscope and D8DiscoverGADDS model and analyses sample, ooze is boracic and diamond film, the adherent force of diamond film uses exterior Rockwell hardness plan (120 ° are conic model diamond pressure head, 150 ～ 1500N) evaluates load. Have integration analysis and opinion to this experiment through above method. 2, result and the exterior form appearance after analysing boracic pretreatment of 　 · ooze and material of composition analysis underlay are razor blade of smooth YG6 hard alloy. Graph 1a is the exterior form appearance of primitive YG6 hard alloy, its surface is slick, without cave apparently and raised; The pickling of underlay is thick changing processing is to use rare hydrochloric acid to corrode 60min, with the Co of purify underlay surface, thick the burnish of Al2O3 sand paper that 10mim uses after changing, the diamond that is W1, W5, W10 with granuality is pulverous with 1:1: 1scale undertakes mixture, bath of acetone of the reoccupy after abrade underlay surface makes an appointment with 20min is supersonic clean, the purpose is the nucleate density that increases diamond, increase the adherent power of diamond film. Graph 1b is sample 2 in pickling thick the exterior form appearance after changing, the surface appeared even imperceptible uneven, WC grain is shown apparent; Sample 3 with sample 4 undertook ooze boracic pretreatment, ooze boracic pretreatment used solid ooze boracic method, graph 1c and graph 1d are sample respectively 3 with sample the exterior form appearance of 4 ooze boron, can see, sample 3 because ooze is boracic deeper cause, underlay color hair is dark, have hole; Sample the exterior hole after 4 ooze are boracic is less, grain is petty, ooze boracic layer is successive. The XRD of surface of the underlay after ooze boracic pretreatment can table chart is shown 2 times like the graph. Graph 2a is sample 1 namely the XRD graph of primitive and smooth hard alloy, graph 2b and graph 2c are sample respectively 3 with sample the XRD after 4 ooze are boracic pursues. Observe discovery from graph 2b and graph 2c, through the wave crest of W2CoB2 appearing after ooze boracic pretreatment, at the same time WC wave crest somewhat abate. In ooze boracic process, the agent offerring boron that participates in ooze boron to react is carbonization boron (B4C) , activator is Potassium of fluorine boric acid (KBF4) , sodium carbonate (Na2CO3) . Graph the graph of underlay surface SEM after 1 different pretreatment begins to heat in ooze boron when, the agent that offer boron and activator reaction generate active B atom, reaction process is as follows: KBF4=BF3+KF(1)2BF3+2BC4+O2=3BF2 ↑ + 7[B]+2CO(2)2KF+B4C+O2=K2O+BF2 ↑ + among them BF2 is 3+CO(3) not to stabilize gas, give boracic atom via decomposing analyse and form stable BF3 gas, reaction type is 3BF2=+2BF3 ↑ (4) is in type (the BF3 that 4) gets can react with B4C happening again, produce active atom, such go round and round, final work out offers boracic agent B4C. The active boracic atom that reaction place generates will be adsorptive produce reaction to the surface of hard alloy and Co and WC, form the compound such as W2CoB2. Reaction mood comes into being ceaselessly as a result of atomic for 2W+Co+=W2CoB2 (5) , with the compound that diffused to form stability to exterior Co from underlay interior, eliminated Co thereby the adverse effect in the deposit process of diamond, and formation ooze boracic layer is OK and effective the Co of interior of ground block up diffuses the surface, the WC that regards hard alloy as main body at the same time is in ooze boracic layer same existence, what this assured underlay is successional, nonexistent also other bring to bear on transfer the problem that exert oneself adds between layer and underlay. Sample 2 because passed pickling only abrade thick change, exterior composition did not produce change basically; Sample 3 in the quality mark of WC and W2CoB2 is respectively 68.

5% with 31.

5% ; Sample 4 in the quality mark of WC and W2CoB2 is respectively 65% with 35% . Sample 4 in the surface contains boron to measure prep above sample the main reason of 3 was to add rare land, rare earth has the apparent effect that urge ooze in ooze boracic process, namely more Co formed compound in underlay surface, form compact ooze boracic layer thereby. If the graph is shown 3 times,the SEM of exterior form appearance of appearance of form of surface of · diamond film and film of diamond of CVD of adherent force 　 pursues, graph 3a is sample the exterior form appearance of film of 1 deposit diamond, because did not pass any pretreatment, in deposit process cannot effective form nucleus, become film consequently poorer, and adherent force is very poor, appear in brim place fall off phenomenon. Graph 3b namely sample 2 courses pickling is thick change, diamond film grain is bulky and successive, brilliant form is clear, brilliant form growth is good, present a typical case (111) brilliant face, the surface is rougher; Graph 3c is sample the exterior form appearance of the diamond film of the 3 deposit after using ooze boracic pretreatment, present a crystallization to spend what differ a bit (the diamond film of 100) orientaton; Sample 4 those who use is the ooze boracic pretreatment that adds rare land, diamond grain submits bulbiform brilliant form, the surface is even and successive, nucleate density is high and exterior surface roughness is small. By the graph 3 visible, sample 4 in the as a result of rare earth action urging ooze when ooze is boracic, make the content that the surface forms W2CoB2 higher, what held back Co effectively is oozy, formed fine the diamond of grain is filmy. 3d of graph of 　 of 3c of graph of 　 of 3b of graph of graph 3a 　 pursues SEM of surface of film of diamond of the CVD after 3 deposit pursues the article uses Rockwell impress law to be opposite deposit diamond film undertakes force is evaluated adhering to, graph the 4 impress pictures that to be in action of identical load 1000N leaves. Can see from inside the graph: The sample in graph 4a 1 because did not pass pretreatment, diamond film adds exert oneself extreme difference, film is great fall off; The sample in graph 4b 2 courses pickling is thick change, crackle of apparent sex of disperse the internal heat with sudorifics is not had all round impress, but the area diameter that film falls off all round impress is bigger; The sample in graph 4c has flaw of partial diverge sex all round 3 impress, all round filmy section is broken, its add exert oneself poorer; The sample in graph 4d film falls off all round the impress of 4 area is less than sample apparently the desquamation all round 2 impress area, crackle of disperse the internal heat with sudorifics is very few, its add exert oneself to have a competition the adherent force of 2 raises kind somewhat; The impress area of 4 is less than sample sample the impress area of 3, did not see apparent diverge flaw, can decide from this sample the adherent force of 4 is the most powerful. As a result of,the reason basically is sample 4 in added rare land, rare earth has the effect that urge ooze, underlay ooze boron is deeper, alleviated stress of one part surface, make adherent force increases, the deposit that is helpful for diamond film rises with what add exert oneself. If make conclusions,can reach from this: Use method of ooze boracic pretreatment, and the adherent force of 4 wants the sample that rare land added in ooze boracic agent the sample after excel pickling is abrade the adherent force of 2, below the premise that assures adherent force, through ooze boron pretreatment can win the diamond film with slick surface. Graph SEM of impress of 4 diamond film pursues (load is 1000N) 　 3, the article uses verdict method of ooze boracic pretreatment, pass heater CVD law, smooth diamond film gets in preparation of surface of smooth hard alloy. Both neither of new method of ooze boracic pretreatment destroys original underlay the precision of slick surface and bright and clean degree, can assure the adherent force of underlay again, be helpful for raising the smooth sex of diamond film. In ooze boron temperature is 950 ℃ , ooze boracic time is 6h, ooze boracic agent is W(B4C)=71% , w(KBF4)=14% , w(rare earth) =5% , below the condition of W(Na2CO3)=10% , to smooth hard alloy apparently the adherent strength effect of deposit diamond coating after pretreatment is most ideal, its add the adherent strength after pickling of exert oneself excel is abrade, at the same time rare earth rose to urge ooze action in ooze boracic process, make the boride content of underlay surface increases, the deposit that is helpful for diamond film rises with what add exert oneself. The article considers to use do not injure new technology of underlay surface pretreatment, in surface of slick hard alloy underlay, the smooth diamond that won demand of contented and adherent power is filmy, because film of groovy to solving diamond is coarse, polishing difficulty is great and a title that cannot use on industry pattern and wear-resisting parts of an apparatus have direct effect, be helpful for widening diamond film stuff wears away in attrition at the same time the application in the domain. CNC Milling