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Design-Manufacturing and Performance Studies of Diamond Drill

Author: ChenZuo
Tutor: HuangShuTao
School: Shenyang University of Technology
Course: Mechanical Manufacturing and Automation
Keywords: Diamond drill SiCp / Al composites Finite Element Analysis Drilling experiment
CLC: TG713.1
Type: Master's thesis
Year: 2010
Downloads: 294
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Abstract

With the rapid development of science and technology, such as of SiC particle or fiber reinforced aluminum matrix composites, high-silicon aluminum alloy, and ceramics and other non-ferrous difficult to machine materials. Non-ferrous difficult to machine materials due to its high specific strength, high stiffness, high temperature resistance, corrosion resistance and other excellent performance, making it an increasingly wide range of applications in the aerospace, automotive, manufacturing and other fields. Corresponding to its cutting quality and efficiency have put forward higher requirements. However, such materials are present difficulties in machining, tool wear is a big problem. For drilling, the problem is even more serious. Diamond tool has many excellent properties of high hardness and high wear resistance, turning, milling get a good application, but the drilling in the study. Diamond drill design study is necessary and significant. Summarized analysis on the basis of composite machining Research and diamond drill, diamond drill bit difficult to process non-ferrous material efficient precision drilling of design and manufacturing problems, and cutting research. Basis SiCp / Al composites cutting, especially drilling characteristics and performance characteristics of the diamond tool diamond drill the overall design concept, the proposed diameter of not more than 10 mm diamond drill welded structure; than 10mm The use of machine folder structure. Mainly welded diamond drill analysis. First of Pro / E to create a three-dimensional model of the diamond drill two sharpening model based on drill sharpening the plane sharpening cone sharpening model, two different flank shape diamond drill bit. Application of ABAQUS finite element analysis software for PCD inserts compressive strength analysis of different flank shape after angle, angle blade compressive strength and draw out the curve, the blade can withstand the maximum axis value to the cutting force. The results show that: axial cutting force increased to 2400N, the blade to withstand the stress value of the pressure reached its maximum compressive strength and began to appear destruction; same axial cutting forces, the flat grinding of PCD inserts are compressive stress value representing small, i.e., compressive strength better; addition, PCD inserts by the compressive stress increases with increasing rear corners, wherein the flat sharpening the blade by the compressive stress values ??increase significantly, conical surface sharpening the blade by the compressive stress The increasing trend is more gentle. Also obtained by calculating the point angle of the impact of its compressive strength, the apex angle of larger PCD inserts compressive strength better. The second chapter of of different BTA trench and different radial truncate spiral groove diamond drill torsional rigidity analysis study. Establish the straight flute chip removal and spiral groove the BTA two different BTA trench diamond drill three-dimensional model, and obtained by the finite element calculation of the twist angle of the drill, get straight groove diamond drill torsional rigidity than the spiral groove diamond drill period of arc-shaped diamond drill torsional rigidity than traditional truncate conclusion. In addition, by changing the design parameters of the diamond drill bit structure simulation during the drilling drill force analysis, comparative study of drill core thickness, helix angle, the length of the spiral groove diamond drill stiffness strength. Wherein with increasing thickness of the core drilling, the radial displacement, the axial displacement and angular displacement of the diamond drill are reduced, the greater the thickness of the core drilling, the better the rigidity of the drill. But the drill core thickness over the General Assembly reduce drill bit chip space, increased BTA difficulty, a large number of chips piled another drill core thickness increase means that the cross will aggravate the wear and tear of the drill bit BTA tank to reduce the quality of the life of the drill bit and processing; edge length is increased, this will cause the chisel cutting conditions deteriorate, particularly a diamond drill bit, PCD inserts having a brittle, will lead to the increase of the axial force, if the chisel blade is too long, an increase of the blade in the drilling destruction probability, diamond drill bits should not be excessive increase in thickness of the drill core. Increase the maximum angular displacement of the drill helix angle increases torsional stiffness decreased. Diamond drill before the angle is zero, no impact of the helix angle of the cutting edge, a large helix angle is more conducive to the discharge of chips, can reduce the likelihood of lead to drill failure because the chips accumulated in the chip removal groove. However, the helix angle is too large, it will to growth Paixie away and chip resistance. If the BTA is not smooth, the chips will be stacked in the BTA tank will cause poor cooling conditions, diamond drill, PCD inserts at high temperatures easily graphitization; another diamond tool cutting forces generated in the processing therefore consider the diamond drill helix angle slightly larger than the helix angle can be selected in the case of a smooth chip removal. The increase in the length of the helical groove of the bit will cause the decline of the torsional stiffness of the drill bit. The analysis also obtained the drill stress distribution in the drilling process. The results show that the chisel edge, the spiral groove root and the cutting edge at the stress concentration, and drill the most easily damaged parts. The drilling process is one of the machining, the most complex, the most widely used process. Due to the the special drill geometry complex process, processing inappropriate choice of processing parameters will cause the drilling force is too large, the tool life is short, flutter and drill breaks results generated in the process. Chapter one created by the large-scale finite element software ABAQUS diamond bit drilling SiCp / Al composites mathematical model, using the simulation model of drilling, the drilling force predicted processing diamond drill suffered axial force and torque as well as workpiece stress distribution analysis comparing diamond drill under different cutting parameters of the axial force and torque, the trend to provide a reference for the follow-up performance experiments. Cutting force values ??obtained by simulation under different cutting parameters, and to map out the relationship between the cutting force and cutting parameters curve, observational studies have been drilling axial force and torque with the increase in the amount of feed increases with the cutting speed Increase the right conclusions of the axial force and the torque variation is small. Chapter diamond drill drilling of SiCp / Al composites drilling experiment studies, drilling speed and feed rate of the drilling force, the surface roughness of the impact of the law; drilling experimental study of the diamond drill drill cut SiCp / Al composite diamond drill bit wear, breakage mechanism and forms. The following conclusions: First, the amount of feed is a key factor affecting the size of the axial force during the drilling, with the increase in the feed amount of axial force increases, tool wear is accelerated, while the machine vibration is also increased significantly; cutting speed little effect on the axial force, consistent trend of cutting force simulation results. Secondly, diamond bit drilling of SiCp / Al composites, mainly for wear and breakage. Wherein the wear include the rake face wear, flank wear, and the lateral edge wear, the wear mechanism including abrasive wear, adhesive wear, diffusion wear, chemical wear, etc.; breakage includes cutting edge chipping, flaking and drill broken. Analysis of diamond drill bits and high-speed steel drill bit drilling SiCp / Al composites when flank wear the VB value Drilling number between relations. High-speed steel drill machine a hole wear and tear on the very serious, it is not suitable to be used to the machining experiment in SiCp / Al composites, and the diamond drill is ideal for drilling SiCp / Al composites tool, but must be in the coolant strong impact cut BTA role. Finally, also discussed cutting parameters of the axial hole roughness, the feed rate of the level of surface roughness plays a key role, the feed rate increases, the surface roughness increases, and vice versa. The drilling speed of the surface roughness Ra of little effect, but when the speed is too high, since the cutting vibration and other reasons, the surface roughness will increase.

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CLC: > Industrial Technology > Metallurgy and Metal Craft > Cutting tools, abrasives,abrasive tools,fixtures,molds and hand tools > Tool > Hole Cutter > Drill
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