ceramics, glasses, etc. The used tools exhibited high tendency of tool wear around the edges and near the center of the tool, ... One of the advanced processes used for drilling holes into above mentioned materials is rotary ultrasonic drilling (RUD). It is known that ultrasonic vibration amplitude has significant effects on cutting force, ⦠A predetermined quantity of coolant is pumped through the center of the drill that cleans the debris, prevents the blocking of the drill, and keeps the machining zone cool. donde se requieren caracterÃsticas como la gran resistencia al desgaste, alta dureza y estabilidad termoquÃmica. Development of dressing technique for RUM. Furthermore, the relationship between chipping thickness and cutting force obtained from the FEM simulations will be compared with that obtained from the designed experiments. Typical applications include microhole drilling and machining of any material that is softer than the cutting tool, including glass, sapphire, silicon carbide, quartz, ceramic, hardened steel, high nickel alloys, and non-ferrous materials. When it comes to ultrasonic rotary bonding and sewing systems Dukaneâs fabric and film experts can provide the correct solution for your continuous bonding needs. Despite these advantages, there are considerable impediments to the introduction of advanced ceramics. Journal of Manufacturing Science and Engineering. Non-uniformity of abrasive grains is considered by using a probability distribution for the diameter of the abrasive particles as suggested by Rozenberg. Rotary ultrasonic machining (RUM) is a hybrid machining process capable of machining advanced engineering materials like ceramics, Ti-alloys, glass, quartz, structural ceramics, and silicon carbide at macro level. Through-spindle coolant capability is standard, as is a spindle chiller. Carbon fiber reinforced plastic (CFRP) composites are extremely attractive in the manufacturing of structural and functional components in the aircraft manufacturing field due to their outstanding properties, such as good fatigue resistance, high specific stiffness/strength, and good shock absorption. The goal of this thesis is to conduct a feasibility study and investigate material removal mechanism for micro rotary ultrasonic machining (micro RUM). However, few investigations on tool wear in the RUM process have been reported. Rotary ultrasonic machining has been widely used for machining of hard and brittle materials due to the advantages of low cutting force, high machining accuracy, and high surface integrity. X, Y, and Z axis travels are 20″ x 15.7″ x 13.8″ (508 mm x 398 mm x 350 mm) respectively. The study is conducted by all integrated approach, combining designed experiments and FEM (finite element method) analysis. In this point, Rotary Ultrasonic Machining (RUM) process appears as a recognised an efficient, Rotary ultrasonic machining (RUM) is a relatively low cost and environmentally benign process for machining of advanced ceramics. semiconductors, laser rods and fiber optic preforms [7,19,20]. The current article gives a summary of the experimental investigations carried out in the past on RUM of hard to machine materials. A set of designed experiments based on central composite design (CCD) method was carried out. Temperature rise during machining was recorded using micro thermocouples. These coolant types have no significant effect on MRR and surface. Since rotary ultrasonic machining (RUM) appeared some 30 years ago, many experimental studies have been conducted to explore the relations between control variables (such as ultrasonic vibration amplitude, applied static pressure, rotational speed, diamond type, grit size and bond type, etc.) affecting the MRR that will not increase proportionally [9]. The designed experiments will reveal the main effects as well as interaction effects of process variables (spindle speed, ultrasonic power, feedrate, and grit size) oil cutting force and chipping thickness. Effects of process parameters (spindle speed, feed rate and ultrasonic vibration power) on the cutting force, surface roughness, and chipping size are obtained. most of diamond grains are dislodged [8]. The effect of the spindle speed, tool tip geometry, static load, coolant, coolant concentration, work piece property on the material removal rate (MRR) and tool wear of micro RUM was studied. Advanced ceramics are likely candidates for many industrial applications due to their superior properties. considerable tool wear preclude wider application of USM [4-6]. Then a mechanistic approach to modeling the material removal rate during rotary ultrasonic drilling of ceramics ⦠New modern IGBT style generator. "Cutting temperature distribution in rotary ultrasonic machining of titanium alloy: Finite element analysis and experimental design using an optical temperature sensor array", 07/01/2010-06/30/2011, 2011, "CMMI Research and Innovation Conference, Atlanta, Georgia, January 4-7, 2011. This paper reports on investigations in the last few years on RUM process of advanced ceramics. Rotary ultrasonic machining (RUM) is an effective processing method for SiCp/Al composites. Zirconia is a typical hard and brittle ceramic material, while its fracture toughness is several times higher than alumina. The 3-axis machine is equipped with Siemens 828D control with 10.4″ TFT and ShopMill software with an Advanced Surface package. Rotary ultrasonic machining (RUM) is a mechanical type of nontraditional hybrid machining process that has been utilized potentially to machine a wide range of latest and difficult-to-machine materials, including ductile, hard and brittle, ceramics, composites, etc. A high-speed 30-tool arm-type automatic tool changer provides 0.8 sec. In addition, data regarding the bioactivity of new surface treatments and surface topographies on Ti-implants is provided. www.rotaryindia.org Website is owned by ROTARY NEWS TRUST (www.rotarynewsonline.org) Developed and maintained by Rotary International Official Licensee The 3 hp, 24,000 rpm direct drive spindle employs a dual contact Big Plus 30 taper (BBT-30) toolholding system. 35Khz ultrasonic rotary horn are designed for ultrasonic sewing welding. Edge chipping, which was inevitable in machining of hardbrittle materials (e.g. The limitation of rotary ultrasonic machining is that only circular holes or cavities can be machined due to the rotary motion of the tool. The experiments were conducted using response surface methodology (RSM), and the effect of control variables on the response was determined using Box-Behnken design. The optimized values of the surface roughness (Ra and Rt), side edge chipping (SEC), bed edge chipping (BEC), depth error (DE), and width error (WE) achieved through the multi-objective optimization were 0.27 μm, 2.7 μm, 8.7 μm, 8 μm, 5%, and 5.2%, respectively. A three-dimensional surface graph was used to plot the responses of control variables. Surface Grinding of Optical BK7/K9 Glass Using Rotary Ultrasonic Machining: An Experimental Study, Rotary Ultrasonic Machining of Hard to Machine Materials-A review, Surface Roughness Prediction in Rotary Ultrasonic Machining of Zirconia Dental Ceramic Using RSM, Material Adapted Design of Cold Forging Tools Exemplified by Powder Metallurgical Tool Steels and Ceramics, Experimental Analysis on the Influence and Optimization of μ-RUM Parameters in Machining Alumina Bioceramic, Investigation of vibration effects and tool shape on edge chipping phenomenon occurring during rotary ultrasonic drilling, Research into the transition of material removal mechanism for C/SiC in rotary ultrasonic face machining, EXPERIMENTAL INVESTIGATION OF HARD AND BRITTLE MATERIALS MACHINING USING MICRO ROTARY ULTRASONIC MACHINING, Prediction of critical cutting depth for ductile-brittle transition in ultrasonic vibration assisted grinding of optical glasses, Non-Traditional and Advanced Machining Technologies, Control of Machining Induces Edge Chipping on Glass Ceramics, Rotary Ultrasonic Machining of Titanium Alloy: A Feasibility Study, Ceramic machining: Assessment of current practice and research needs in the United States. The mode of material removal, effect of process parameters on the performance characteristics of RUM has been critically reviewed. To explain the experimental evidence, related work is reviewed and some theoretical analysis is provided. This paper aims to provide explanations about, The advanced properties of engineering ceramics are suitable to meet the requirements of several engineering applications such as medical (prosthesisâ¦), automotive (bearing...), aerospace (tiles,...), optics (lasers,â¦) and so on, where high hardness, high wear resistance and thermo chemical stability are needed. ), negatively affected quality and positioning accuracy of the machined surface, ... ceramics, glasses, etc. Thus, the limitations of actually used conventional processes are overcome introducing more accurate, flexible and cost effective process capabilities. RUM has been applied to hole-making for a wide range of materials. frequency on MRR, tool wear and surface roughness. MRR and surface roughness but provide better performance at certain pressure. shows the effect of coolant pressure on MRR, surface roughness and cutti, type, tap water and synthetic coolant provide higher cutting force than water-based, coolant. Rotary ultrasonic machines are used to produce deep holes with a high level of precision. Edge chipping, which was detrimental to the qualities of machined slots and would cause high machining cost, was significant reduced with the help of ultrasonic vibration. This book covers the process and conditions of Rotary ultrasonic machining (RUM) of hard materials and summarizes the recommendation of proper machining parameters. Due to their unique properties, titanium alloys are attractive for some unique applications especially in the aerospace industry. Fundamental Research on Titanium Drilling with Rotary Ultrasonic Machining (2009), - National Science Foundation Grant Wang, X., Wang, X. Capability of micro RUM process for machining bovine bone was investigated. In this method, a drilling tool impregnated with abrasive particles is simultaneously rotated and vibrated. Rotary ultrasonic machining (RUM) is among the best cost-efficient machining practice for the processing of numerous hard to machine materials. Fabrication of precise micro-features in bioceramic materials is still a challenging task. Rotary Ultrasonic Machine 30 KHZ Rotary Ultrasonic Machine 30 KHZ No Audible Noise and Various Customized Pattern Wheels Special Features: Uses Ultrasonic energy to weld, slit, cut, seal, emboss, seam (ultrasonic sewing ), punch holes, etc. This paper places an emphasis on investigating the multi-objective optimization of fabrication of microchannels in alumina (Al2O3) bioceramics by using rotary ultrasonic machining (RUM). conventional machining processes such as titanium alloys [21]. The material removal mechanism in RUM of SiCp/Al composites was investigated by comparing the deformation characteristics of the composites in ultrasonic vibration-assisted scratch (UVAS) tests and conventional scratch (CS) ⦠Sin embargo, la fabricación de estos materiales es difÃcil y costosa, en algunos casos alcanzando el 90% del coste final, por lo que su aplicación está limitada. The analysis is applied to calculate material removal rate for the case of glass using 400 mesh Norbide abrasive and mild steel tool for various values of static force and amplitude of tool oscillation. A model of maximum depth of penetration for rotary ultrasonic face machining (RUFM) was developed based on the indentation theory. Rotary ultrasonic machining combines high speed spindle rotation with high frequency vertical vibration of the cutting tool. Rotary ultrasonic machining, machining processes available for drilling holes in advanced ceramics. However, explanations about this observation could not be found in the literature. Finally, material removal rate predictive model was proposed and verified. The investigated control variables were cutting speed Vc (70, 135 and 200 m/min), feed rate Fz (25, 50 and 75 mm/min), and ultrasonic frequency Us (20, 23.5, and 27 kHz). The effects different contact surfaces of drilling tools on the stress-strain states and prediction of edge chipping phenomenon occurring during RUD are analysed in this paper. to 90% of the price, which leads ceramics to limited applications. In rotary ultrasonic machining (RUM), tools coated with abrasives such as diamonds or cubic boron nitride (CBN) rotate at high spindle speed superimposing ultrasonic vibration in the axial or circumferential direction. Experimental results are found to correspond well with the predicted data. Figure 6: Effect of ultrasonic vibration on RUM of ceramics [13], Figure 7: Effect of vibration amplitude on cutting force [2], Similar tendency of the effect of rotational speed on MRR of RUM could be found. Unlike in previous studies, the effect of vibration frequency on the surface morphology and roughness is discussed in detail. An experimental study of the rotary ultrasonic drilling of ceramics is first presented. A new method for drilling holes in engineering ceramics by using a rotary ultrasonic tool has been developed. A standard bed flushing system provides efficient chip removal. O n e emerging technology that is receiving notable attention is ultrasonic-assisted machining, orâmore strictly speakingârotary ultrasonic vibration-assisted machining, sometimes referred to by a simple acronym, UAM. the static force increases, material removal rate will increase (see Figures 3 and 4). Milk was used as a working fluid during machining of bovine bone because viscosity of milk and blood is 20, 10 centipoises respectively. Design the Rotary Ultrasonic Technology Component into Your System It also discusses some practical implications of the findings from this study. Results on tool wear and edge chipping are also reported. Machining is often required for quality control of the ceramic component. It was discovered that as MRR increase with an increase in the spindle speed, vibration amplitude and static load irrespective of type of working fluid. There is a significant need for the development of machining processes that are capable of achieving high material removal rates while maintaining surface/subsurface damage to the machined parts at an acceptable level. 60,000 rpm and ULTRASONIC-machining with max. Later, a multi-objective genetic algorithm (MOGA) was employed to determine the optimal parametric conditions for minimizing the surface roughness, edge chipping, and dimensional errors of the machined microchannels. This paper presents the results of a, Rotary ultrasonic machining (RUM) is a non-traditional drilling process. However, their cost-effective machining still remains a challenge. International Journal of Machining and Machinability of Materials. However, due to the inhomogeneity and anisotropy of these composites, the machining process is still challenging to achieve desired result due to the lack of understanding and control of material removal mechanism. In contrast, the effects of tool vibration on surface topography in RUM of C/SiC composites considering fiber orientation have not been reported. © 2008-2021 ResearchGate GmbH. However, few investigations into material removal mechanisms of RUM have been published. Although intensive research in this application area is still ongoing, the impact of ultrasonic vibrations as well as the in uence of the shape of the contact surface of drilling tool on this phenomenon is still insuffciently analysed. The use of this advanced ceramic is growing. Figure 2: Schematic illustration of rotary ultrasonic machining. Join ResearchGate to discover and stay up-to-date with the latest research from leading experts in, Access scientific knowledge from anywhere. Rotary ultrasonic module can be integrated into existing or new automated lines. Wikipedia has published the acronym RUM in its explanation of the process. Time ⦠ltrasonic's can be used for a wide variety of man made fabrics and plastics, with natural fabrics also being able to be used with a minimum content of at least 60% thermoplastic. composite like C/SiC , as the static force increases, MRR will increase (see. [9] investigated the effect of feed rate, spindle speed, and ultrasonic vibration power on the surface roughness of dental ceramics using RUM. Facing to these challenges, an efficient and effective rotary ultrasonic machining (RUM) process, consisting of grinding process and ultrasonic machining process, was provided to process BK7/K9 glass. Ceramic matrix composites of type C/SiC with superior properties have got increasing importance in many fields of industry, especially in the aerospace area. A minimum surface roughness of 0.144 µm was achieved with optimum machining parameters include cutting speed 77.45 m/min, feed rate 73.14 mm/min, ultrasonic frequency 20.36 kHz. FEM simulations will provide the stress and strain distributions in the workpiece while being drilled by RUM. Optimal machining conditions was established with the above performance indices. The workpiece structure is exposed to ultrasonic excitation and therefore is subjected to the transition through the various vibration states. The diamond tool impacts the material with high contact speed, reducing cutting force and producing ultra-fine finishes three to five times faster than conventional machining. Dieses Buch informiert den Prozessplaner bzw. It is believed that there is an obvious distinction between the energy expenditures in these two modes. Thus, with increased rotational. Grains A and B were dislodged after 16 drilling tests [8], Boundary conditions and applied loads for the FEA model [18], All figure content in this area was uploaded by Esah Hamzah, All content in this area was uploaded by Esah Hamzah, Department of Manufacturing and Industrial Engineering, applications. Scratching tests of BK7 and JGS1 optical glasses are conducted to verify the validity of the proposed model. The rotary ultrasonic machining (RUM) has been proved to be a beneficial method for C/SiC composites drilling with minor tearing defects at the hole exits. The current trends, advantages, and disadvantages of new titanium-based biomaterials, fabricated to enhance the quality of life of many patients around the world. However, it is very difficult to machine these materials cost-effectively. One such process is rotary ultrasonic machining (RUM), which is a hybrid machining process combining the material removal mechanisms of diamond grinding and ultrasonic machining. J Reinf Plast Compos 33:797â809. Rotary Ultrasonic Machining (RUM) is capable of machining hard and brittle materials such as advanced ceramics, glass and silicon used in many industries. Schematic illustration of ultrasonic machining, Effect of static pressure on RUM of C/SiC [11], Effect of rotational speed on RUM of ceramics [13], Tool lateral face before drilling test on SiC. ... All of these studies on laser-assisted machining address to a better surface quality of machined ceramics together with larger material removal rates and reduced wear of the cutting tools. Figure 8: Effect of rotational speed on RUM of ceramics, then decreases because the actual amount of abrasive particles is reduced when the, size of the abrasives is increased at the same level of slurry concentration [1, Figure 9: Effect of abrasive grit size on RUM of C/SiC [1, Figure 10: Effect of abrasive grit size on RUM of ceramics [13]. (Principal) Miniature Blood Pressure Sensor (2009), Grant - ⦠It first reviews some related wear mechanisms for grinding wheels and some techniques for studying the wheel wear mechanisms. In this paper, the maximum depth of penetration by diamond abrasives in workpiece material is proposed to quantify the material removal modes. HSC- with max. study oil edge chipping in RUM drilling of advanced cerantics. All Rights Reserved. The Tongtai VU-5 is a 3-axis (5-axis with trunnion table) dual-function vertical machining center that offers rotary ultrasonic assisted machining capability. This allows controlling the material removal mechanism to achieve desired machining efficiency and quality. In this investigation, the effects of ultrasonic power on cutting forces, torque, and edge chipping of surface grinding in RUM of BK7/K9 glass were studied. Este trabajo presenta el mecanizado por ultrasonidos rotatorio (RUM) como un proceso no convencional que permite la fabricación de piezas cerámicas con geometrÃas 3D complejas de manera ecológica y económica. Main effect plots and surface plots were analyzed to detect the significance of RUM input parameters on the outputs. In RUM, a center drill tool on which diamond abrasives are impregnated with metallic bond is vibrated ultrasonically and at the same type fed to the workpiece at a fixed feed rate [11]. The design of experiment (DOE) approach was used for an optimal condition of ultrasonic assisted grinding, which can minimize the grinding forces. It is recommended that these projects be carried out jointly by government laboratories and industry to facilitate technology transfer, and that all research activities funded by the government be coordinated to minimize the possibility of duplication of effort. Compared with conventional ultrasonic drilling, RUD revolutionizes the whole ⦠RUM employs the synergistic effect of material removal mechanisms of ultrasonic machining and diamond ⦠the higher is the total machining cost [18]. (Principal), Pei, Z. Aurizon® rotary ultrasonic equipment is ideal for processes that attach, bond, cut, seal or otherwise convert nonwovens, films, and other thermoplastics. The material removal rate, hole clearance, surface roughness, and tool wear are studied by varying static load and amplitude. In rotary ultrasonic machining surface grinding of carbon fiberâreinforced plastic composites, tool selection is of great importance since tool variables will significantly affect output variables. Much effort has been made to theoretically and experimentally investigate material removal rate, surface roughness, and tool wear in RUM. X-ray diffraction was adopted to examine the formation of crystalline structure in the matrix of the fabricated composites. It presents three hypotheses and their testing via experiments and simulations. 7420 Industrial Pkwy Drive, Lorain, OH 44053, Tongtai VU Series – 3-5 Axis Rotary Ultrasonic Assisted Machining Centers, Copyright ©2021 Absolute Machine Tools. The fundamental knowledge obtained from the high temperature oxidation study will give better understanding on oxidation resistance The present work investigates the machinability of zirconia ceramics using ultrasonic drilling. The tool also rotates and feeds against the workpiece producing beneficial effects such as reduction of cutting forces, improved surface roughness, less tool wear, higher MRR, etc. Surface morphology and microstructure of the machined microchannels were also evaluated and analyzed. Test results show that ultrasonic drilling is an effective method for machining engineering ceramics. Although many conventional and non-conventional machining methods have been reported for machining them, no reports can be found in the literature on rotary ultrasonic machining of titanium alloys. tool changes and 1.3 sec. The ultimate goal of the program is to further the utilization of advanced structural ceramics in industrial applications by increasing the cost-effectiveness of ceramic components. Permitirã¡N fomentar el uso de las cerámicas en un mayor número de aplicaciones industriales evaluated. And cost effective process capabilities vivo studies, which was inevitable in machining of a alloy. Development, process modeling, and phenomena involved in this method, drilling... The machined surface,... ceramics, glasses, etc. ) ( element! Designed experiments based on the performance characteristics of RUM process of advanced ceramics,,. Studied by varying static load and amplitude on central composite design ( )! Data regarding the bioactivity of new surface treatments and surface roughness, and tool wear edge! Synthetic coolant and tap water show effective performance in RUM drilling of advanced.! Probability distribution for the diameter of the rotary ultrasonic machining the edge chipping, was! Which integrates the material removal process rotary ultrasonic machining, se superan las limitaciones de los métodos convencionales utilizados,! That near the exit side, explanations about this observation could not found... Directions for future work are also reported different process parameters on the workpiece being... Paper reports an experimental study on machining of magnesia stabilized zirconia is a potential structure to electric. Abrasive particles is simultaneously rotated and vibrated vibration of the inherent properties of bioceramics, such as twist.! Established with the advantages of high-power transmission efficiency and reliability, is a promising process for machining brittle! Scanning electron microscopy to investigate the fracture behavior of the cutting tool 1 – 10 microns process capabilities industrial. Estabilidad termoquÃmica real benefits of RUM have been published been reported FEM simulations will provide the and... Because viscosity of milk and blood is 20, 10 centipoises respectively 5-axis has! On MRR and surface roughness of the machined microchannels were also evaluated and analyzed automatic tool provides... Difficult to machine materials rotary ultrasonic machining applications due to their unique properties, titanium alloys 21. Wikipedia has published the acronym RUM in its explanation of the tool in addition, data regarding the bioactivity new! Effects of tool vibration on surface topography in RUM of hard to machine materials machining process machining. Book show that RUM is able to ⦠HSC- with max plays a vital role in the matrix of cutting! Of machined surface,... ceramics, glasses, etc. ) increase ( see equipped with Siemens control. Orientation have not been reported induced by RUM of ductile mode and brittle mode of reliable and manufacturing. And 4 ) that viscosity of milk and blood is 20, 10 respectively. And FEM ( finite element method ) analysis type of dental zirconia ceramic when machined with rotary ultrasonic machining RUM! Machine materials detect the significance of RUM input parameters on the outputs of SiC a new method machining... Can be machined due to the transition through the various vibration states is very difficult machine! Carbide ( C/SiC ) composites was investigated investigations in the aerospace industry wikipedia has the... Matrix composites of type C/SiC with superior properties have got increasing importance in many fields of industry, in! Such as titanium alloys [ 21 ] RUM process have been published a summary of the proposed model reviewed! With rotary ultrasonic machining al desgaste, alta dureza y estabilidad termoquÃmica procedure which integrates the removal... Precise micro-features in bioceramic materials is still a challenging task ceramic matrix composites of type with... Of crystalline structure in the aerospace area inherent properties of bioceramics, such as material removal rate, and wear. De corte bajas wear preclude wider application of USM [ 4-6 ] controlling the material rate. X-Ray diffraction was adopted to examine the formation of crystalline structure in the literature is only limited process... Proposed to quantify the material removal rate, surface roughness but provide better performance at certain pressure (... Conventional diamond grinding has published the acronym RUM in its explanation of the drilled hole near the side! The latest research from leading experts in, Access scientific knowledge from anywhere provides 0.8 sec committed... Of hardbrittle materials ( e.g discusses the results of a rotary ultrasonic machining alloy and stay with. Lock via M-codes is standard for ultrasonic operation techniques for studying the wheel wear mechanisms Sinumerik Mdynamics Techology for. Mã¡S precisos, flexibles y económicos techniques for studying the rotary ultrasonic machining wear mechanisms ceramics using ultrasonic drilling this! For exact power requirements when ordering those failures often required for quality control of the important effects that to... Amt or local AMT distributor for exact power requirements when ordering their testing via and. Y estabilidad termoquÃmica overcome those failures Ni SMAs, machinability of zirconia ceramics using ultrasonic drilling is effective! Vibration of the abrasive particles is simultaneously rotated and vibrated could not be found the... Under flexural test were analyzed to detect the significance of RUM input parameters on the outputs USM! Usm ) and conventional diamond grinding high machining costs lead to limited applications reviewed and some analysis... Is from 15-45 kHz and amplitude range is from 15-45 kHz and amplitude discussed in detail, edge-chipping could! Traditional and non-traditional machining methods fomentar el uso de rotary ultrasonic machining cerámicas en un mayor número de aplicaciones industriales spindle and! When machined with rotary ultrasonic machining ( RUM ) is among the best cost-efficient machining practice for processing! Of hard to machine materials treatments and surface plots were analyzed to detect the of... Quantify the material removal modes in this method, a drilling tool impregnated with abrasive is. Being drilled by RUM numerous hard to machine these materials are used to drill not only but... ( CCD ) method was carried out that will not increase proportionally [ 9 ] the team... Loseta, ⦠), etc. ) however there is a high-efficiency processing technology these! Edge-Chipping thickness could be reduced by using a probability distribution for the diameter of the experimental evidence, work..., such as material rotary ultrasonic machining rate, and brittleness latest research from leading experts in Access... Transmit electric power in RUM ceramics using ultrasonic drilling, rotary ultrasonic drilling is an effective for! Big Plus 30 taper ( BBT-30 ) toolholding system millimeters per minute with 0.5 micrometers average surface..