In submerged conditions before and after mixing abrasive jet impact angle, flow, pressure

Using FLUENT software, submerged abrasive jet multiphase flow simulation, calculation of different structural forms of the nozzle flow field inside and outside. Explored the submerged condition after mixing abrasive jet impact angle, flow, pressure, target distance, sand tube length, tube diameter mixed sand, abrasive concentration,  synthetic diamond  change on the nozzle flow field inside and outside the law, on the abrasive particles running track were predicted, while the flow field  polycrystalline diamond  and calculation results are analyzed. For premixed abrasive water jet, respectively, direct numerical simulation of 260,450,600 cone type nozzle and external flow field and grain motion characteristics, and submerged jet  abrasive grinding  under influence factors - target distance, angle of impact and confining pressure for the simulation analysis. The results showed that: there is a submerged abrasive jet jet core, is about (35) D, but then jet decay rapidly. Cylinder, cone, cone straight three typical straight-type nozzle nozzle cone best, and to 260 straight cone nozzle effect is better.

Explained rotating abrasive jet nozzle jet nozzle wear serious than ordinary phenomenon

Comparison of the rotating abrasive jet nozzle and the general stress abrasive jet nozzle, the results showed that: the former is much larger than the maximum stress in the latter, which could well explain the rotating  Polycrystalline diamond  nozzle jet nozzle wear serious than  abrasive grinding . Study of the various parameters of the law of the nozzle wear, these parameters were as follows: the abrasive characteristics (shape abrasive,  Diamond blade  size, grain hardness, abrasive concentration), nozzle material properties and surface quality (hardness nozzle, abrasive hardness H_α and nozzle material hardness H_m ratio nozzle processing quality), nozzle structural parameters (inlet contraction angle, nozzle diameter), the jet operating parameters.

Small screw motor driven mechanical gimbal drive alloy drill fenestration

In a variety of technology to improve oil recovery, the radial horizontal well technology with its operating procedures are simple, the process cycle is short, less investment, etc. showed good technical and  abrasive grinding . Applications at home and abroad to open a small window radius horizontal well technology uses small screw driver alloy  synthetic diamond  driven mechanical drill fenestration, because underground space constraints, the level of domestic screw motor technology is difficult to meet the requirements. To this end we introduce rotating abrasive jet  cutting tools , and its realization casing window, expand the relevant theoretical analysis and experimental research tools designed to promote open small window radial level technology application in China.

Based abrasive water jet cutting efficiency and high rotating jet good scalability characteristics

The traditional radial drilling technology requires forging mill and a large diameter casing reaming, operating procedures and more difficult construction. Casing window radial horizontal well technology simply open the casing with a diameter of about 30 mm of the window, to the formation of radial drilling channels. At present, foreign multi-use mechanical window. Based abrasive water jet cutting efficiency and high rotating jet good scalability characteristics, the author proposes a  synthetic diamond  jet technology line window, and through numerical simulation and laboratory tests to analyze the combination of means for the further development and improvement of open  Polycrystalline diamond  technique provides a theoretical basis. Injury and damage criterion variable in metallic materials RVE, assuming a  Abrasive grinding  area A normal vector is n, the micro-cracks or micro-voids exist, resulting in an effective bearing area A Zhou ratio A small, that Zhou A = A-AD. AD is considering stress concentration defects and defect area after interaction. In the assumption of isotropy of the premise, the damage variable defined as a defect area and the total area ratio, i.e. D = ADA = A-Zhou AA. (2) when D = 0, the metal material is non-destructive condition; D = 1 , the metal material is completely broken;

Combination of different impeller nozzle to simulate structural characteristics and results rotating jets of various factors

The newly developed rotary abrasive jet casing window tool, using numerical simulation method, the tools to optimize the structure and size of the design . Rotate tool abrasive jet casing window is the core component of the jet nozzle and rotating impeller . From the nozzle and impeller geometry and basic characterization can be seen, leaf number, as well as export-oriented angle nozzle diameter and other parameters that affect the efficiency of rotating abrasive jet major factor . Numerical method, the combination of different impeller nozzle simulation results and the structural  Diamond blade  of rotating jets of various  synthetic diamond  jet spread angle of rotation rule ; through the individual abrasive particle erosion simulation casing , the casing draw stress , strain change process , abrasive particles displacement, velocity change process , as well as the depth of various factors on the impact of erosion pits law ; abrasive jet by  abrasive grinding  window full-size simulation tool , draw nozzle phase fluids inside and outside the field distribution of the casing and a rotating abrasive jet erosion damage process . Finally, the structural parameters of the impeller nozzle size optimization , preferably windows meet the requirements of the impeller and the nozzle , and the simulation and experimental results are compared to verify the accuracy of the simulation results .

Mainstream mechanical cutting techniques in cutting

With the offshore oil and gas exploration and development progresses, a number of offshore platforms have completed their mission, platform removal has become a hot project. Platform is one of the key technologies demolition waste wellhead and riser Abrasive grinding of the current foreign mainstream mechanical cutting techniques in cutting, drilling tablets cable cut, shaped blasting abrasive jet cutting and cutting. As is by the multi-layer casing and  Diamond blade  cemented together and there may be eccentric, but need to cut at 5m below the seabed, drilling and mechanical cable cutter grain cutting method is difficult to meet the project needs, and shaped cutting due to blasting a greater damage to the environment, gradually limit the use of;

Research abrasive jet cutting seam technology on the permeability change impact surrounding wells

Abrasive jet slotting well stimulation technique is the use of two-phase jet abrasive mechanism developed for improved oil recovery in an oil field technology. This article from the seepage - stress coupling based theory, a more comprehensive study on the abrasive jet cutting seam technology surrounding wells permeability  cutting tools  analysis slotted the impact on oil production situation. Application of rock, the effective stress and pore pressure, confining pressure and rock properties  Abrasive grinding  slotted through the rock around the well after the stress and permeability variation  synthetic diamond  and analysis, interpretation of the abrasive jet cutting seam technology to increase production wells the basic principle is the rock around the well after slotting the effective stress reduction and increased permeability of the results;

Abrasive jet with a small amount of abrasive particles formed from a mixture consisting of water jet

Abrasive jet slotting mechanism and mechanical model to study in order to establish oil ( water ) wells abrasive jet slotting theory, as the technology continues to improve and the process parameters to provide theoretical support . Slotted underground rock formations require two different types of metals and materials to be cut , so this study for universal abrasive jet cutting is also instructive significance and reference value. Abrasive jet with a small amount of abrasive  synthetic diamond  from a mixture consisting of water jet , according to the abrasive particle size , and the mass and volume of low concentration, uniform distribution , water flow rate is high, the abrasive particles can be characterized flows together with the water can be regarded as sparse balance solid-liquid two-phase flow .  cutting tools  a continuous medium , in the establishment of a solid-liquid two-phase flow on the basis of the basic differential equations , obtained with the solid-liquid two-phase equivalent single -phase fluid of the basic equations. Which can be applied to single-phase fluid mechanics and  abrasive grinding  fluid flow method problem . This paper uses polar coordinates , time-average method to create turbulence equations . By order of comparative law , the equation reduces to the corresponding turbulent boundary layer equations , namely freedom of circular cross-section turbulence abrasive jet differential equations .

Active matrix liquid crystal display is a relatively novel liquid crystal display technology

Active matrix liquid crystal display is a relatively novel liquid crystal display technology, in which each pixel switching by deposition on a large area glass substrate constituting the liquid crystal cells on the surface of a thin film electronic  abrasive wheels . Currently, it is the only - one kind has proved in color, grayscale and image quality can be comparable with the CRT LCD technology. Polysilicon thin film silicon materials have both high mobility and a large area amorphous silicon,  abrasive grinding  of the characteristics, and the active matrix liquid crystal display as the most ideal material thin film electronic device. Preparation of polycrystalline silicon thin film in many ways, including through the group phase crystallization of  Abrasive grinding wheel  thin-film method available polysilicon thin film with excellent performance, but due to the crystallization temperature> 600 "C; must use expensive quartz glass as the substrate; while crystallization time also up to 40h or so, which greatly hindered practical devices and industrialization. summarizes the formation of amorphous silicon and metal eutectic temperature and found that if amorphous metal contact, which will be far lower than the crystallization temperature crystallization temperature of the pure amorphous silicon.

Polycrystalline silicon thin films with the ordinary compared with the more superior film piezoresistive characteristics

Polysilicon thin film piezoresistive properties make it good in piezoresistive sensors have been widely applied. Existing research results show that the polycrystalline silicon thin films as compared with the ordinary polycrystalline silicon thin film has a  grinding wheel  piezoresistive characteristics, so has broad application prospects. In this paper, thin films of polysilicon piezoresistive  abrasive grinding  were studied, including processing conditions on the piezoresistive properties of silicon and polycrystalline silicon thin films Young's Modulus. Piezoresistive characteristics on the basis of research on nano-film polycrystalline silicon pressure sensor applied research. In the process conditions on the piezoresistive characteristics of the study.

Three ultra-high speed grinding of advanced technology in an advanced processing technology

Ultra-high speed grinding technology has been hailed as the "modern grinding peak ," has been listed as the International Institute of Production Engineering Center for the 21st century development. Ultra- high-speed point grinding technology is another new ultra high speed grinding applications forms , is a flexible CNC machining technology , CBN super abrasive , ultra high speed grinding three  Abrasive grinding  in an advanced processing technology . Ultra- high-speed ceramic CBN wheel technology is  abrasive wheels  grinding one of the key points , vitrified CBN grinding wheel because of its excellent performance and production process of the green, environmental protection , energy saving, low power consumption is recognized as a high-speed, high efficiency, high fine, low cost, low  Diamond blade  , high-performance wheels, racing around the world in recent years, the development of hot spots. This article from the ultra high-speed point grinding mechanism analysis start point for ultra high speed CBN wheel grinding ceramic structural characteristics , in accordance with the grinding theory and synthetic material preparation
Principle , its components and their key technologies, manufacturing processes for a more systematic research , and research and development of ultra- high-speed point grinding wheel grinding performance conducted experiments . Concludes the paper , outlining the ultra-high speed grinding technology and its theoretical research areas of development history. Systematically discusses the ultra high-speed ceramic CBN grinding wheel superiority and development at home and abroad .

Rational use of wheel, the use of appropriate electrolyte, select the appropriate electrical parameters

Electrolytic grinding process, including the rational use of wheel, the use of appropriate electrolyte, select the appropriate electrical parameters, using the correct sharpening methods. Carbide (YG) verification test tools, test was designed to improve the electrolytic grinding tools (D7540) performed on. Grinding wheel  abrasive grinding  choice: current  Polycrystalline diamond  many types of electrolytic grinding wheel, we choose two. One is electrolytic copper-based sintered wheel, a sintered  Synthetic diamond  particle size of 60, 30% concentration. Another is an iron-based sintered electrolytic grinding, abrasive is sintered corundum, particle size of 60, 40% concentration. Using the results of two wheels can achieve electrolytic grinding tools, copper electrolytic grinding wheel, grinding of good quality, an anti-electrolysis life of about 60 to 100 vehicles grinding flank.

Without the magnetic properties of granite, is widely used in production of precision measuring tools and instruments and the base platform

With the precision and ultra- precision processing technology, with high hardness, high wear resistance , low thermal expansion coefficient , are not electrically conductive , non- magnetic properties of granite, is widely used in production of  abrasive grinding  and instrument platform and the base , ultra- precision machine tool bed and rails , spindle, spindle box and workbench. The traditional processing methods granite widespread low processing efficiency and quality problems . Belt grinding is developed in the sixties and advanced machining methods. It has a high processing efficiency , " cold " grinding , grinding speed and stability,  abrasive wheels  , grinding and low cost , in the machinery manufacturing plays an increasingly important role , is now widely used in ordinary metals , difficult to machine metals plane , inside and outside the circle , the processing of complex shaped surfaces . Abroad in granite, marble, ceramic , glass and other  abrasive grinding  materials aspects of belt grinding process carried out some exploratory research . In this paper, abrasive belt grinding technology in the hard stone processing applications were reviewed . Belt grinding characteristics compared with the ordinary grinding wheel , abrasive belt grinding has the following salient features.

cBN crystal in color from light to dark

Graphite-like hexagonal boron nitride (hBN) as raw materials in the growth of the participation of alkali metal out of the cBN. Pure cBN should be colorless, however, artificial growing out of cBN crystal often are colored, it is because the cBN crystal in the presence of different impurities. Currently, cBN crystals in color from light to dark can be roughly divided into colorless, orange, amber, dark amber and black. The most  cubic boron nitride  and black cBN crystals. Different colors of crystal has its own inherent nature of significant differences. With industrial development,  synthetic diamond  grades, especially high-grade cBN  Abrasive grinding . From the perspective of the development market in the world cBN, cBN demand every year more than 18% growth rate. Currently, the world's annual production of about 200 million karats cBN, with China accounting for half of the country, not only in quantity but also in quality are highly competitive.

CBN preparation, properties and n-type doping

CBN because of its high hardness, high thermal stability and chemical stability, excellent physical and chemical properties, and much attention. In recent years, cubic boron nitride thin films and properties of international research has been one of the hot, but it is also one of the difficulties. This paper studies the preparation of cubic boron nitride, nature and content of the n-type doping. RF sputtering on Si synthetic diamond powder  were successfully prepared high-quality cubic boron nitride film, reached the international advanced level. And a negative substrate bias voltage of the RF power on the preparation of cubic boron nitride thin films of cubic Abrasive grinding is deposited on the P-type substrate, the target for the h-BN target, the sputtering gas is a mixture of argon and nitrogen and Cheng, sample preparation process, the substrate plus DC negative bias. Film composition by infrared absorption spectroscopy and X-ray photoelectron spectroscopy logo, film morphology observed by atomic force microscopy. Experiments show that cubic boron nitride thin film nucleation and growth conditions of the window is very narrow, so difficult to synthesize cubic boron nitride films. To get the cubic boron nitride film, a negative bias can not be less than 90V, the power can not be less than 200W. When the negative bias of 200V, 300W, when the film cubic phase content of 92.8%.

Metal bond diamond wheel machining

And compared to traditional grinding wheel, diamond grinding wheel for machining hard grinding hard, brittle materials; especially in precision grinding with high precision, high speed, long life and other advantages of the grinding wheel, while the use of metal bond diamond wheel machining, the effect is more significant. along with new materials (such as: hard, brittle, magnetic materials, precision ceramics and special properties of the ceramic coating, new superalloys, etc.) in the application of Abrasive grinding , diamond grinding wheel will get  Synthetic diamond  applications. Because of the new material is very difficult using conventional grinding wheel, the grinding force is not only a low production efficiency, grinding loss, more important is difficult to obtain high machining accuracy and surface quality.

Parallel to the contact line is an involute gear end

Full Duty vertical honing wheel design theory honing process, the honing surface of the tooth space of the contact line is a curve, only the engagement of the contact line is located at the point of abrasive grinding action only, it should be a very big waste. Work gear (spur) tooth surface of the contact line is a parallel to the end face of involute gear, first gear  Diamond blade  and engineering using  cubic boron nitride  method to find space for the contact surface of the tooth honing curve equation, and then convert it to honing tooth face, the obtained equation abrasive grinding , and then face tooth with this objective optimal minimum error approximation fitted to facilitate grinding involute blade type, blade type on the face of all this grit on can participate grinding, and this end of the workpiece edge type conjugate gear a space curve.

Honing tooth surfaces are involved in cutting all the effective range

Throughout the process of honing cutting, honing tooth surface to be machined gear tooth surface will achieve line contact along its  Abrasive grinding  tooth meshing line cutting, honing tooth surface so that all of the valid range are involved in cutting (so called full cutting ), so that the ability to greatly improve the cutting tool, the tool life was extended. The research was supported by the technology in Shanxi synthetic diamond powder  and technological project funding. This paper focuses standard involute gear teeth on the whole cutting type honing surface design done basic research and discussion. Whole cutting type honing wheel involute tooth surface is cylindrical envelope surface, which is more complex mathematical equations.

Processing honing tooth surface to be machined gear tooth surfaces

Hardened gear honing is a highly efficient method of precision machining, precision manufacturing the gear which plays an important role. Therefore, honing technology improves precision manufacturing of the gear has a very important significance. Common  synthetic diamond powder  tooth involute helicoid tooth in the process of honing the workpiece surface and the tooth surface is a point contact, and thus the processing  abrasive grinding is relatively low, limiting the ability of the honing tool into full play. In this paper, ordinary honing wheel this deficiency, the whole design of honing the cutting type were studied. Full Duty honing wheel is engaged gear machining based on the study proposed a new hardened gear honing tool.

Sand sand adhered to the surface of the adhesive film

Old sand sand the surface condition of foundry sand for molding or core system, you need to use a certain amount of grit adhesively bonded together, so the adhesive will adhere to the sand surface to form an adhesive film, attached to sand surface force,  cubic boron nitride . The binder itself between molecules, there are links between power, a cohesive adhesive. Sand sand sand sand the surface condition of the adhesive film  Abrasive grinding to the surface, changing the surface abrasive grinding  of the sand. According to the solid surface energy theory, this would allow the sand surface energy decreases, when once again adding new adhesive, the two-phase interface activity is reduced.