• فهرست مقالات Ultrasonic machining

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        1 - Precision Force Measurement and Control in Micro Ultrasonic Machining
        Hamid Zarepour Firouzabadi
        Micro ultrasonic machining (Micro-USM) is a process with a great capability to generate micro features in hard and brittle materials. Despite some developments in micro-USM process, issues such as precision measurement and control of the machining force, which is crucia چکیده کامل
        Micro ultrasonic machining (Micro-USM) is a process with a great capability to generate micro features in hard and brittle materials. Despite some developments in micro-USM process, issues such as precision measurement and control of the machining force, which is crucial for stable machining conditions, need further investigations. In this paper, the precision measurement and control of the machining force is studied using a newly-developed force measurement configuration. The results of the force measurement for different levels of static force, abrasive particle size and amplitude of vibration demonstrated that the variation of measured machining force increases at higher static forces. Furthermore, a better control over the static load was acquired when feeding the abrasive slurry with particle size of 0.37 mm as compared to 1 mm and 3 mm particles leading to more stable machining conditions in micro-USM process. Finally, applying lower levels of vibration amplitude to the workpiece resulted in more stable machining conditions and lower static load errors. پرونده مقاله
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        2 - Prediction of Material Removal Rate in Ductile–Mode Micro Ultrasonic Machining
        Hamid Zarepour
        This paper presents a model to predict Material Removal Rate (MRR) in Micro Ultrasonic Machining (micro-USM). The proposed model is developed based on the ductile-mode of material removal in micro-USM process. The correlation between ductile material removal rate and pr چکیده کامل
        This paper presents a model to predict Material Removal Rate (MRR) in Micro Ultrasonic Machining (micro-USM). The proposed model is developed based on the ductile-mode of material removal in micro-USM process. The correlation between ductile material removal rate and process parameters including frequency and amplitude of the ultrasonic vibration, particle size, and slurry concentration is presented. The proposed predictive model is verified by performing micromachining experiments using two types of workpiece materials including silicon and quartz at various process parameters levels. The results show that the MRR increases with a rise in vibration amplitude for both silicon and quartz materials. The experimental MRR values follow a trend similar to that of predicted MRR values. However, the predicted MRR values are higher than the measured MRR values for both silicon and quartz materials. The measured MRR values for ductile removal mode were found to have a considerable increase at vibration amplitudes of 2 mm and 2.4 mm for silicon and quartz, respectively, which is in favour of increasing the accuracy of the model prediction. پرونده مقاله
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        3 - An Experimental Investigation on Surface Roughness and Edge Chipping in Micro Ultrasonic Machining
        Hamid Zarepour
        Surface quality including surface roughness and edge chipping is a key process measure in microultrasonic machining (Micro-USM) as an efficient process for micromachining of hard and brittlematerials. Process parameters such as ultrasonic vibration amplitude, static loa چکیده کامل
        Surface quality including surface roughness and edge chipping is a key process measure in microultrasonic machining (Micro-USM) as an efficient process for micromachining of hard and brittlematerials. Process parameters such as ultrasonic vibration amplitude, static load, type of toolmaterial, type and size of abrasive particles and slurry concentration can influence the surfacequality. However, there is limited study on the parametric effects on the surface quality in micro-USM. The objective of this study is to investigate the effects of the workpiece material as well asprocess parameters including abrasive type, particle size and vibration amplitude on surfaceroughness and edge chipping in micro-USM. Silicon, alumina ceramics and soda-lime glass wereselected as workpiece materials and polycrystalline diamond and alumina as abrasives. Particle sizeranging from 0.3 to 3 μm and vibration amplitude ranging from 0.8 to 3 μm were selected in thisstudy. Results indicate that workpiece material and vibration amplitude have significant effects onsurface roughness. Workpiece material was found to be the most significant parameter with apercentage contribution of about 45 % in the variation of mean Ra, followed by vibration amplitudeand particle size of about 28 % and 5% contributions, respectively. Results also show that aluminaceramic is a material capable of achieving better surface quality in micro-USM as compared tosilicon and soda-lime glass. پرونده مقاله
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        4 - Development of Design and Manufacturing Support Tool for Optimization of Ultrasonic Machining (USM) and Rotary USM
        Morteza Sadeghamalnik Mohammad Rasoul Najafi
        Ultrasonic machining (USM) is a mechanical material removal process used to erode holes and cavities in hard or brittle work pieces by using shaped tools, high-frequency and an abrasive slurry. This paper addresses the concept and development of an expert system (ES) fo چکیده کامل
        Ultrasonic machining (USM) is a mechanical material removal process used to erode holes and cavities in hard or brittle work pieces by using shaped tools, high-frequency and an abrasive slurry. This paper addresses the concept and development of an expert system (ES) for hard and brittle material, such as glass, quartz, diamond, carbides, semi conducting materials, ceramic and graphite which can be manufactured with ultrasonic machine or rotary ultrasonic machining. The expert system is developed based on object oriented technique. The system links with a feature based CAD system in order to extract design data. The expert system is linked with databases. The machining cycle time, cost, penetration rate and productivity, of each selected design feature are estimated. The system provides useful information such as machining cycle time and cost, penetration rate and efficiency of machining of the selected design feature for product designers and manufacturing engineers to select optimum machining parameters. Also the expert system compares ultrasonic machining (USM) and rotary ultrasonic machining (RUSM) for the same design feature in concurrent engineering environment. پرونده مقاله