Get together abrade craft and mechanism study brilliant diamond

The relation of quantity of purify of material of graph 1 PCD and abrade time pursues the concern plan 3 PCD of surface roughness of surface of 2 dry abrade PCD and abrade time does D of abrade purify quantity and law to get together to the relation of load F brilliant diamond (the hardness that PCD) has adjacent and natural diamond, wearability, it is one kind is applied extensively at the data of new-style cutting tool that nonferrous metal and metalloid material nicety process. To fill cent develops the good performance of PCD cutting tool, improve the exterior quality that machines a spare parts, face of the knife before cutting tool (PCD surface) need to machine lens face. Current, PCD lens face uses emery wheel of colophony radical diamond to have abrade treatment normally, but close of the diamond abrasive hardness that uses as a result of PCD and place, property, having with conventional abrade treatment consequently very big different, its are abrade mechanism, abrade the metabolic law that craft has oneself. The article undertook to PcD abrade craft relatively systematic research, abrade to its mechanism undertook more thorough analysis. Experiment of 1 experiment condition gets together in BDJP-902 undertake on brilliant diamond muller; The type of diamond emery wheel, norms, dimension is 6A2 250 × 50 × of 36 × 5 120 B 100, emery wheel speed is 18.

3m/s, ; Test specimen is the triangular 1600PCD90T5/1 that American GE company produces.

Base of 6 standards knife. To raise experiment precision, reduce trial error, be in on a collet in the meantime abrade the PCD knife semifinished product with 3 same size, consumed relatively the purify thickness that appearance measures every knife base, take its average to regard purify as the quantity. Observe with interferometer, measure configuration of PCD abrade surface and value of surface roughness Rz, use JSM-5600LV scanner to observe PCD abrade surface is microcosmic form appearance. The influence figure that cooling fluid of 2 tests result reachs exterior surface roughness to purify rate is shown 1 times work for PCD abrade (abrade before emery wheel nap 10 seconds, cooling fluid was not added in abrade area) and wet abrade (abrade before emery wheel nap 10 seconds, cooling fluid is added in abrade area) the metabolic case that quantity of purify of the material below two kinds of conditions follows abrade time. The action when the experiment is 20N to load in the law on test specimen collet. By the graph 1 knowable, purify of dry abrade material leads the relation with Q doing and wet Q of rate of purify of wet abrade material to be: Abrade and earlier Q does =2.

54Q is wet; Metaphase Q does =1.

6Q is wet; Q of stable state period does =1.

68µm/min, o of Q wet ≈ . Observe with interferometer, measure PCD surface configuration and surface roughness: Wet abrade when PCD apparently put in a lot of deep indentation, abrade stripe of its surface interference still is shown after 130 minutes intermittent condition, namely Rz>0.

3µm, face of short of lens asks; Dry abrade when Rz reduces exterior surface roughness along with the extension of abrade time, its relation curve is shown 2 times like the graph. By the graph 2 knowable, abrade when 20 minutes, PCD surface amounts to lens face (Rz ≯ 0.

05µm) , and lengthen surface roughness of abrade time surface again basic invariant, but observe according to exterior configuration the result is knowable, its flatness rises somewhat. Accordingly, treatment of PCD lens face should use dry abrade technology, below experiment condition, abrade 30 minutes of its surfaces can amount to 20 ～ lens face; If the flatness demand to abrade surface is higher, can extend abrade time appropriately. The influence attempt that the law leads to purify to load shows the law that goes up in test specimen collet for the action when PCD doing is abrade 3 times to lead the impact of Q to load F and material purify. By the graph 3 knowable, material purify leads Q to increase to the accretion of load F as the law, and existence folds bit of A(F=15N) , when ≤ 15N, its purify leads Q to increase as the accretion of F with lesser extent, when F>15N, its purify leads O to increase as the accretion of F substantially. 3 results analysis and mechanism discuss the matter that produces afore-mentioned test results to make clear, need to undertake discussing to mechanism of PCD material purify. Graph 4 PCD is not abrade 6 PCD of graph of appearance of form of wet abrade surface does 5 PCD of graph of exterior form appearance appearance of abrade surface form is wet abrade purify mechanism pursues 4, graph 5 it is PCD respectively the SEM photograph of appearance of form of not abrade, wet abrade surface. By the graph knowable, although wet abrade surface is uneven also, but as concave and convex as not abrade surface condition differs completely, apparent existence flakes in great quantities hole. This kind of phenomenon explains PCD surface produced brittleness purify. The author thinks means of its brittleness purify is dynamic brittleness purify (namely fatigue brittleness purify) is not static carry brittleness purify. Because,this is abrade condition laxative remedy to load F lesser (20N) , the ultimate stress that in PDD apparently stress issues generation crackle under dead load greatly is worth action, because this is basic,won't happen static carry brittleness purify. But British scholar Coopr ever pointed out through the experiment: Diamond falls in the circular action that pounds load, the stress that produces crackle is worth the static stress that needs under place greatly. And the PCD in abrade process piece susceptive is to hand in change concussion load, because this will produce fatigue brittleness purify. Wet abrade when the brittleness purify means of PCD material is purify of this kind of fatigue brittleness. In the graph 5 in still can observe at the same time local and flowing area, this is the result of purify of unripe thermochemistry of PCD local hair. Because of wet abrade when although cooling fluid is added inside abrade area, the attrition heat of the generation between PCD surface and emery wheel is taken away by cooling fluid for the most part, abrade area is average temperature is inferior, but still can produce local high temperature to contact a dot, make here PCD material produces the thermochemistry purify of oxidation, graphitization. This shows, PCD material is wet abrade when, its purify mechanism is given priority to with fatigue brittleness purify, put in local thermochemistry purify at the same time. The SEM photograph that works PCD of abrade purify mechanism to do abrade face is shown 6 times like the graph. Can see from inside the graph its surface presents flowing form appearance, do not have basically flake hole, material of the PCD when demonstrative doing is abrade does not produce fatigue brittleness purify basically. The author thinks, dry abrade when behoove of machine of PCD material purify is given priority to with thermochemistry purify. Because work,this is abrade when cooling fluid was not added in abrade area, the attrition heat of the generation between bead of stone mill of the King Kong in PCD material surface and emery wheel can pass PCD only piece diffuse with emery wheel go out, abrade area is so average temperature is higher. Additional, in high temperature condition of blame high pressure falls, black lead or amorphous carbon are thermodynamic go up stable structure of carbon, the hardness of diamond as temperature elevatory (T>350 ℃ ) and reduce, and abrade be undertake below air atmosphere, PCD material surface will produce oxidation, graphitization, at the same time the surface still can produce certain hardness bate layer. At the same time bead of stone mill of the King Kong in emery wheel also will produce oxidation, graphitization, produce hardness bate layer, but degree is smaller, and hardness of layer of bate of PCD of prep above of the hardness that wear bead. Because work abrade when on the matrix that cooling fluid adds in emery wheel to be not working layer, bead of stone mill of the King Kong in emery wheel is initiative temperature is inferior, because this grinds a working temperature to compare PCD piece low; Additional, the instantaneous that wear bead carries abrade district, time of its heat preservation compares PCD piece short, research makes clear: Temperature is constant, diamond is burned break rate show linear to increase as heat preservation time; And accelerant of the remaining in PCD material is gotten etc, make its produce oxidation, graphitization and hardness bate further again below condition of high pressure of high temperature blame. So, dry abrade when the thermochemistry purify of PCD material includes PCD appearance purify of oxidation, graphitization and because grind hardness of layer of bate of PCD of bead hardness prep above and the mechanical purify with certain generation, because produce the account of unripe mechanical purify,be the result of hot action, call mechanical hot purify here so. The place on put together is narrated, as a result of dry, wet abrade when mechanism of PCD material purify is different, bring about thereby dry, wet abrade when material purify rate is apparently different, namely Q of Q dry ＞ is wet. Wet abrade when material purify mechanism is given priority to with fatigue brittleness purify, and dry abrade when material purify mechanism is given priority to with thermochemistry purify, do not produce fatigue brittleness purify basically, so wet abrade cannot make PCD surface reachs lens range, and dry abrade wear away when emery wheel will make PCD surface reachs lens range when certain level. Work abrade when, as the law accretion to load F, abrade area temperature will be elevatory, PCD material produces thermochemistry purify more easily, so mouth of its purify rate increases to the accretion of load F as the law (3) seeing a picture. The viewpoint of Er of You Ye case is knowable: Temperature rise and load F become direct ratio. Accordingly, material purify leads Q to should become direct ratio basically with F, but graph 3 in put in the A(F=15N) that lose a point however, the point of view of this and Ye case Er is not contrary, just nod in order to fold bit of A for dividing line, the thermochemistry purify kind of PCD material produces change just. When F ≤ 15N, as a result of the law to load F lesser, abrade area is average 750 ℃ of temperature T ＜ , accordingly its thermochemistry purify will heat up purify means to give priority to with machinery, it is with means of purify of local oxidation, graphitization complementary; When F ＞ 15N, abrade area is average 750 ℃ of temperature T ＞ , its thermochemistry purify will reach means of mechanical hot purify to undertake with PCD surface oxidation, graphitization at the same time, because rate of this material purify is ambitious,the purify at F ≤ 15N is led. From afore-mentioned analysises knowable: Only dry abrade ability makes PCD surface reachs lens range, and the purify mechanism of the material when PCD doing is abrade is thermochemistry purify, because this can try use the price,the is not bead of King Kong stone mill emery wheel with cheap, higher melting point has abrade treatment, in order to reduce the finished cost of PCD cutting tool; Work abrade when, rate of expensive stuff purify is brought necessarily abrade hind aggravate of bate of PCD surface hardness, this will affect the service life of PCD cutting tool on certain level, accordingly treatment should use the lens face of PCD surface to decrease the dry abrade technology that carry gradually, can carry taller abrade efficiency already, can reduce again abrade hind the bate degree of exterior hardness. 4 knots treat of looks into PCD surface wet abrade when, the purify mechanism of material is given priority to with fatigue brittleness purify, put in local thermochemistry purify at the same time. PCD surface works abrade when, the purify mechanism of material is given priority to with thermochemistry purify, do not produce fatigue brittleness purify basically. Thermochemistry purify means reachs mechanical hot purify for PCD surface oxidation, graphitization. The lens face treatment of PCD surface should use dry abrade technology, and should use decrease the abrade technology that carry gradually, this can carry taller abrade efficiency already, can reduce again abrade hind the bate degree of exterior hardness, prolong the service life of cutting tool thereby. Below experiment condition, 1600PCD is dry abrade 20 ～ can amount to lens face 30 minutes, if load increases, abrade time can shorten further. Muller of PCD lens face manages is with thermochemistry purify is given priority to, can try to use the price the is not bead of King Kong stone mill emery wheel with cheap, melting point and taller hardness has abrade treatment to PCD material, in order to reduce finished cost of PCD cutting tool. CNC Milling