High-pressured abrasive water processes project ceramics

Pottery and porcelain of 111 introductive projects has wear-resisting, anti-corrosive, hardness advanced a variety of good performance, it is a kind of very hopeful new material. Because project pottery and porcelain has taller hardness and wearability, because this uses traditional metallic cutting to machine a method very difficult, basically use the non-traditional machining method such as ultrasonic, laser to come true to the treatment of pottery and porcelain at present. The article uses pottery and porcelain of project of cut of efflux of high-pressured abrasive water, considered to discuss the effect of main craft parameter to cut deepness through the experiment. The fundamental of pottery and porcelain of project of treatment of water of abrasive of 2 high pressure 2.

If the graph is shown 1 times,water of abrasive of high pressure of 1 treatment principle machines principle of project pottery and porcelain, when high-pressured water efflux enters mixing chamber, the sheds scooter velocity of sound 2-3 of water times. Because this is in abrasive entry point, generation very big negative pressure pump comes from the abrasive of abrasive storehouse. When abrasive and the water that shed classics nozzle mix, generation joint action is in wallop of very big abrasive water efflux on project pottery and porcelain. Because project pottery and porcelain is brittleness material, when its surface is knocked power by strong favorable opposition, the crackle that produces certain length, as the accretion of wallop, crackle is ceaseless and patulous, cut bits to fall off from surface of pottery and porcelain. Graph principle of pottery and porcelain of cut of water of abrasive of 1 high pressure 1.

Abrasive 2.

High-pressured water 3.

Sapphirine nozzle 4.

Mixing chamber 5.

Abrasive water nozzle 6.

Pottery and porcelain 2.

The formation of crackle of concussion of abrasive of 2 high pressure the abrasive that place of pottery and porcelain of project of cut of high-pressured abrasive water uses is natural garnet abrasive, because abrasive contains a lot of edges and corners to present irregular figure, abrasive is in of high-pressured water when driving workpiece of pair of pottery and porcelain to undertake pounding, abrasive itself rises to pound the action of pressure head to, produce local crackle in surface of project pottery and porcelain so, the critical negative charge that generates crackle is Pc. α , the parameter that concerns with the geometrical appearance of pressure head; Kic, of workpiece material rupture tenacity; Hv, the diamond pyramid hardness of workpiece material. When wallop is more than Pc crackle expands, form cut bits. Abrasive is opposite when pottery and porcelain is pounded, as a result of its abrasive is pounded continuously, produce small cutting effect to pottery and porcelain, because this is returned while crackle is patulous quickly,in its the surface produces certain furrow. If crackle of surface of pottery and porcelain and furrow pursue the SEM photograph place of 2 is shown. Graph the appearance of fracture surface form of pottery and porcelain of Al2O3 of cut of water of abrasive of 2 high pressure (500 × ) 2.

Water of abrasive of high pressure of analysis of motivation of percussive of water of abrasive of 3 high pressure is as follows to the wallop of pottery and porcelain what type shows F=(ρ 0+ ρ ) .

ρ of Av2 　 　 , the density of current; ρ 0, the density of abrasive; A, the cut area of abrasive nozzle; V, speed of abrasive water efflux. Normally the pressure P of V and water becomes direct ratio, namely V=k0p1/2 among them: K0 is coefficient of proportionality. Because the pressure P of this wallop and water also is direct ratio, namely F=k0a(ρ + the factor that ρ 0)P3 experiment studies to affect deepness of cut of material of pottery and porcelain is very much, basically speed of pressure, cut, target is apart from, diameter of abrasive granuality, nozzle. The article considers to be below the case with other particular condition only, the impact that cut pressure and cut speed lead to excision. This test has on machine of high-pressured water cut, the greatest pressure is 400MPa, the largest flow is (4-8) L/min, most high-power is 55kW, high-pressured nozzle uses sapphirine, nozzle diameter is 0.

3mm, abrasive uses garnet, granuality is 60 eye, type is mixed after mixture method is, diameter of mixture antrum nozzle is 1.

1mm, cut speed limits is (0-30) M/h. Project pottery and porcelain uses Al2O3 and B4C. Its physics function expresses place to show as follows. The compressive strength of name of mechanical performance list of pottery and porcelain / MPa tensile strength / the model measures flexibility of MPa Mohs hardness / MPa is microscopical hardness Al2O31800(25 ℃ ) 210(25 ℃ ) 93.

℃ of 79 × 1053000B4C2900(25) 350(25 ℃ ) 9.

34.

1054500 　 of 94 × the cut width of 　 Al2O3 and B4C and diameter of mixture antrum nozzle are consistent, because Al2O3 is softer than B4C, because of this Al2O3 cut relatively the cut level off of B4C, the cut deepness of pottery and porcelain of project of cut of high-pressured abrasive water basically depends on pressure P and cut speed V, graph 3 for pressure and cut deep the relation curve between. Can see from inside the graph, cut pressure heighten, cut deepness increases. Because cut pressure increases,this is, wallop increases, accordingly cut deepness increases. This agrees with afore-mentioned theoretical analysises. Graph 4 for cut speed and cut deep the relation curve between, can see from inside the graph, cut rate increases, cut deep drop instead, as a result of,this basically is of cut speed increase, perpendicular wallop is reduced, horizontal cut force adds, cut deepness is reduced. Graph the relation of 3 pressure and cut deepness (cut fast 6mm/min, target is apart from 3mm) graph 4 cut fast with cut close relationship (pressure 310MPa, target is apart from 3mm) pottery and porcelain of project of cut of water of 4 conclusion use high pressure is a kind of practical method. Look from the cut of two kinds of test specimen, because the hardness of Al2O3 is more inferior than B4C, the cut of Al2O3 relatively the cut level off of B4C, what exterior surface roughness also compares B4C is low. The Mohs hardness of garnet abrasive is commonly 7.

5-9, relatively the hardness of Al2O3 and B4C is low, damaged of abrasive of the garnet when be being used accordingly is serious, lower than efficiency of cut other material. Through the experiment the analysis gets cut deepness and pressure become direct ratio, with nozzle floating rate becomes inverse ratio. CNC Milling