Papers by Keyword: Burr

Abstract: Fine blanking process can produce parts with accurate cutting edge quality. Studying the effects of process parameters on accuracy and quality of fine banking products are usually expensive. In this paper, an innovative idea has been introduced for a set of fine blanking test rig which is not as complicate and expensive as standard fine blanking dies but it could be used alternatively for limited laboratory works. The main concept of the rig is based on manual adjustment of counter punch force and blank holder force by means of rubber spring and torque meters respectively. As a case study, the effect of counter punch force of fine blanking process in a 2mm thickness steel AISI-1006 sheet was studied by this test rig. The results show that increasing the counter punch force makes burr dimension on cutting edge to get smaller which means better quality of the product.

Abstract: This paper discusses burr in microdrilling that affect forms and functions of parts. The effects of microdrilling parameters on burr length and width are identified. The experiment was conducted using Mikrotools DT110 machine with one millimetre diameter of HSS on copper workpiece. Burr heights in terms of burr length and burr width were measured by using scanning electron microscope. The data was analyzed using Taguchi method to find the optimum micro-drilling process parameter for minimizing the burr height. The relationship among spindle speed, feed rate and burr has been developed. It is found that feed rate is the most influential factors on the burr height. The desirability of getting the minimum burr height is 72% and the optimum parameters are 30000 rpm spindle speed and 0.2 mm/min feed rate.

Abstract: Improving machined surface integrity is one of the important issues in the precision machining. This study aims to develop a cutting tool, which enables to generate a local hydrostatic pressure field in the vicinity of the cutting point to suppress the extra plastic flow in the workpiece, because it is known that materials including metals never cause plastic flow and fracture no matter how much greater hydrostatic pressure field is given. In this paper, a simple cutting tool with planer jig is proposed and a molecular dynamics simulation of cutting is performed as the first step. As a result, it is confirmed that the reduction of the plastic deformation, mainly in the burr formation become remarkable with the proposed model due to the suppression of extra side plastic flow, and relatively high-hydrostatic stress field is formed in the vicinity of cutting point. However, it is also observed that relatively many dislocations are generated beneath the cutting groove.

Abstract: The purpose of this study is a practical application of the cavitation aided abrasive machining (CAAM). This study shows the machining effect of the precision abrasive machining on injection molds using the cavitation in a suction flow of slurry, which can easily finish to a fine surface by a simple apparatus. The cavitation occurred above the workpiece surface downstream of the restrictor tip because of the rapid decompression and then the abrasive grains in the water interfere with the workpiece surface by the cavitation impact. In this report, the possibility of application of the cavitation aided abrasive machining to the precision manufacturing of micro air vents on the rib of injection molds are generated by using masks of a certain thickness that are made on a special masking equipment, and the machining characteristics of micro air vents are investigated by analyzing the depth of micro grooves and the surface finish in machining of injection molds. When the depth of the micro grooves is approximately 1μm in the machining of 30 minutes, the manufacture of molding parts without burrs or residual voids is carried out by CAAM.

Abstract: Based on the grinding-hardening test, the types of two-side direction burr were classified; the changing rules of size in the two-side direction burr and the influence of grinding method on the maximum burr size were studied. The results shown, that the size of the burr was increased gradually from the cut-in point to the cut-out point of grinding in one-passes grinding. In two-passes grinding or three-passes grinding, the burr was basically the same. Under this experimental condition, the changing of grinding method affected the height of the burr more, but little to the thickness of the burr root. Meanwhile, the ways of restraining or decreasing the size of the burr in grinding-hardening machining were developed.

Abstract: In view of the generally phenomenon of section burr in of disk shearing, through using the theory analysis combined with FEA software simulation tools in article, exploring the relationship between cutting edge coincidence degree, gap shear process. And take the" taking hierarchical method " get the relationship of the coincidence degree, clearance and strip shearing section level proportion on the factors on shear technology. Finally using the theoretical knowledge demonstrates the accuracy of simulation results.

Abstract: More and more attention is put on the machinability of printed circuit board (PCB) with the increasing demand of PCBs driven by the strong need of the market of the electronic products. In this paper, drill wear and burr size, as two main objects of experimental investigation, have been observed and analyzed in drilling PCB through-holes. The results of the drilling experiment conducted with normal drill and specialized drill, indicate that appropriate chisel edge thinning is in favor of decreasing flank wear of the drill, but has no apparent effect on reducing burr size for PCB through-holes drilling.

Abstract: Metal matrix composites (MMCs) have received considerable attention due to their excellent engineering properties. Accuracy and surface finish play an important role in modern industry. Undesired projections of materials, known as burrs, reduce the part quality and negatively affect the assembly process. In this study, reducing burr size in drilling of MMC is performed by adding ultrasonic vibration to the process. Al/SiC_p MMC with 5 wt% of SiC particulates in dry drilling operation with HSS drill tools coated with TiN was investigated. The effect of ultrasonic assistance on burr size was studied. The results demonstrate that under suitable ultrasonic vibration conditions, in comparison with the conventional drilling, the burr height and width could be reduced.

Abstract: This paper presented the experiments of Nd:YAG pulsed laser cutting of titanium alloy, super-alloy and stainless steel sheet, and investigated the influences of different laser cutting parameters on the surface quality factors focusing surface morphology. In comparison with air-, argon- and nitrogen-assisted laser cutting, argon-assisted laser cutting comes with unaffected surface quality and is suitable for laser cutting with subsequent welding requirement. With analyzing the interaction between pulses overlapping rate and energy, the results show that medium pulse overlapping rate and lower pulse rate helps to improve the surface roughness with pulsed laser cutting. And the results would be beneficial to find optimum cutting parameters for good separation surface.

Abstract: Sheared edge quality of micro IT parts is an important standard to evaluate product quality. In this paper, a prediction model of sheared edge quality based on grey prediction is studied. By mapping the stroke and the burr width to be the time increment and the eigenvalue of grey system, the grey prediction model was established. The dynamic regularity of burr in actual production was attained from the precision blanking experiment and the prediction of burr width was performed. The results show that the model can predict burr width accurately and needs less sampling data. Thus, it is fit for the requirement of manufacturing.