Study On Micro Abrasive Suspension Jet Processing Technology

Micro Abrasive Suspension Jet (MASJ) is a new micro machining process in hard brittle materials. The micro abrasive suspension jet is guide strict pre-mixed slurry to the surface with with a high speed, less than 100μm jet diameter by the use of a fine nozzle, and the material is removed by the collision and impact action between abrasive grain and the workpiece.Compared with conventional micro machining methods, Micro Abrasive Suspension Jet has its own advantage: no Heat-affected zone occurs and the precison of dimension may be controlled easily; the properties of materials don't change and the tool is cooling and removing debris in process for the slurry flows circularly continuously; less than 100μm jet diameter but the cutting ability is almost equal to the Abrasive Water Jet (AWJ). Therefore, MASJ will be specially applied in hard brittle materials.This thesis was based on the application research of MASJ, which was to study and improve the device performance, slurry prescription, nozzle, drilling and cutting. Firstly, on the device improvement, combined with the problem of experiments ,the device named MASJ- I which had been designed all by our lab was improved via the experimental verification on three area. Secondly, on the slurry performance, the selection principle of the major components of the slurry and four evaluation indicators were introduced. Based on experiments, the dosage of the SBN dispersant, the viatery and the different molecular weight and dosage of the PAM, the category of the abrasives was studied according the four evaluation indicators.Thirdly,on the nozzle, effects of the materials and struction of the nozzle were researched to the jet performance and the nozzle wear. Finally, on the processing parameters optimization, online photography method and microscope analysis method of materials, the influence of the processing parameters of MASJ, including jet pressure, processing time, standoff distance, concentration of abrasives,cutting speed, cutting numbers, on the characteristics of the processing area, the diameter, the depth and the removal amount of material of the holes, and the incision width, kerf profile, the quality of the section of the slots, were investigated. Then the relation curves between every individual parameter and the diameter, the depth and the removal amount were obtained, and the rules were summarized ; and then several examples were obtained by using the best combinational parameters of MASJ and the incision width was 0.4mm.The main conclusions were summarized as follows.1. Mixing round the slurry in abrasive vessel on volution principle can reduce the jam and abrasion of the device.2. The dosage of the SBN dispersant was studied in allusion to different kinds of abrasive.3. The different molecular weight and dosage of the PAM were researched. It is found that the best suspensionis the PAM with 5,000,000 molecular weight; and the deep and good quality hole can be obtained by the use of the best concentration of the PAM.4. The category of the abrasives has its influence on drilling, and the corundum abrasive can get the higher ratio of the performance and the price.5. The smaller the diameter of the pinhead grows, the higher the system pressure can receive. And the smaller diameter of jet can be obtained by the use of the best lenght of the pinhead .Finally, the pinhead was used for drilling and the WXG ceramic nozzle was used for cutting.6. Drilling experiment results shows that the effect of the processing time is the linearity direct proportion to the depth of the hole and the removal amount; when the pressure increases at 12 MPa, the trend of the depth of the hole grows slowly, but the diameter is quite the reverse;when the stand-off distance gets to 5 mm, the radiation of the jet gets bigger;good quality hole can be obtained by the use of the best concentration of abrasives.7. Cutting experiment results shows that the pressure increases to obtain the deep slot and good quality kerf profile; to cut for two times is better than for one times in good quality kerf profile; the effect of the cutting speed is obvious; the effect of the standoff distance is biggish to the quality and the shape of the slots, and the best standoff distance is decided on the jet parameters basis; and the deep and good quality slot can be obtained by the use of the best concentration of the abrasives.