Abrasive grinding can effectively prevent surface damage caused by the process of large particles, and simultaneously improve processing efficiency and accuracy

Efficient, high-precision , low surface damage has always been ultra-precision machining pursuit of the goal . With the development of modern industry, for ultra-precision  synthetic diamond  are increasingly high requirements , reduce surface damage and processing to improve the processing efficiency of the contradiction between the increasingly prominent. To alleviate this problem, the research center proposed a fixed abrasive machining and free abrasive machining of semi- solid integration with grit abrasive machining technology, the core of which is the use of having a "trap " effect of semi- fixed abrasive grinding with ultra- precision machining. The abrasive surface can effectively prevent damage to the grinding process caused by large particles , simultaneously improve processing efficiency and accuracy. References of conventional abrasive manufacturing process ,  synthetic diamond powder  the characteristics of semi- fixed abrasive grinding tools , grinding tools for semi- fixed abrasive manufacturing process has been improved, made ​​more perfect machining process. By combining experimental study and additives , determining suitable for semi- solid formulations with abrasive grit . Referring to the traditional abrasive characteristic parameter detection method chosen hardness , shear strength, compression ratio of the key parameters and spring rate , abrasive grinding of these organizations as a semi- fixed abrasive grinding evaluation index , Construction of the evaluation system of semi- fixed abrasive grains . According to the characteristic parameters of semi- fixed abrasive abrasive grit to establish a semi- fixed abrasive PFC models.

Mechanical parts surface finishing field of research and development has rolling mill, magnetic grinding, honing squeeze

Mechanical parts surface finishing field has research and development of new technology, new methods rolling mill, magnetic grinding, extrusion honing, electrolytic chemical polishing, ultrasonic polishing, each method of solving certain problems have very good results. However, whether it is the traditional method or the recently  synthetic diamond powder  are deficient, such as the processing of irregular surfaces, poor control more difficult and do not have the full capability of precision optical cavity surface. This is an urgent need to develop new, more  polycrystalline diamond  to the problem of new abrasive and finishing processes. Compared with the traditional processing methods, magnetic liquid abrasive finishing method has unparalleled advantages, its advantages body in liquid magnetic abrasive finishing method is suitable for finishing outside the irregular surface of the part and the cavity, which because the magnetic grinding fluid rheology, before applying the magnetic field which is a good flow of the liquid, and can fully contact with the cavity surface of the workpiece;

Self-oscillating flow field inside the nozzle chamber variation, internal and external flow field dynamic pressure variation

Abrasive jet formation mechanism of the pulse, the pulse characteristics and pulsed abrasive water jet abrasive jet perforating stimulation mechanism and other issues have been studied, and in the Sichuan Basin, a gas well site experiments. The main  polycrystalline diamond : first using a large eddy simulation, through in-depth analysis of the self-oscillating flow field inside the nozzle chamber variation, internal and  synthetic diamond  field dynamic pressure variation, variation of the velocity vector, turbulence intensity distribution, revealing the self-oscillating  abrasive wheels  jet generation mechanism; combined oscillation, bubble collapse on the abrasive jet impact and solid abrasive water jet in the pulse distribution of abrasive water jet pulses revealed the formation mechanism.

Using perforating fracturing methods to transform strata, increased gas production

Low-permeability gas widely distributed in China, large reserves, proven gas reservoirs representing more than 80%. However, due to porosity, permeability and pressure is low,  polycrystalline diamond low productivity and economic inefficiency. In order to increase natural gas production, to solve the "gas shortage" problem, now mostly using perforating fracturing methods to transform formation, increased  Diamond blade . However, the conventional way of perforation perforation shallow depth, hole diameter is small, the construction for a long time, can lead to gas  Synthetic diamond , resulting in low permeability gas reservoirs, yield poor. For these reasons, this paper proposes a pulsed abrasive water jet perforation penetration increased permeability gas reservoir to increase natural gas production of new ideas.

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.

Water by adding abrasives (ie, abrasive water jet) is to improve the performance of an important way jet

For higher pressure jet working condition, basically limited to some of the research sector from abroad pressure generator and jet equipment research work. Attempts have been made in the high-pressure water jet technology, and continue beyond the new high record Generally said current level of technology enables people to use 200 ~ 400 MPa  synthetic diamond  while with further increase the pressure in the device and the device manufacturing, material, cost and other aspects of life will be limited, there is also the use of security .70 years, people began to note exhausted improve the work efficiency of the jet, focusing on research work  synthetic diamond powder  not too high but with a high-performance jet mechanism, for example, additives jet, 'pulse jet, resonance jet, jet and abrasive water jet cavitation in an attempt to lower operating pressure, achieve a higher economic  cutting tools , added to the water abrasive (ie, abrasive water jet) is to improve the performance of a jet important way. abrasive jet high pressure water jet and general different, it is a highly concentrated jet of energy, the working medium is water and a mixed solution of abrasive particles.

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.