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Recently, rotary ultrasonic-assisted end grinding (RUAEG) has been utilised since it can increment the pace of material elimination and reduce the thrust force. Assigning ultrasonic vibration to the tools was more significant than the other grinding parameters. However, there is no systematic way to choose the cutting parameters to reach efficient outcomes (lower surface roughness and thrust force). The present research employs an adaptive network-based fuzzy inference method to model the RUAEG outcomes, including surface roughness and thrust force, based on the cutting parameters. Moreover, a single objective genetic algorithm is employed to calculate the optimum hyperparameters of the developed adaptive network-based fuzzy inference to reach the highest efficiency. At the end of the process, the multi-objective genetic algorithm is applied to find the optimal machining parameters of RUAEG to achieve the lowest surface roughness and thrust force. The approach is developed using MATLAB with the practically extracted dataset by RUAEG and conventional end-grinding processes of silicon nitride. The optimal cutting parameters are recommended to reach the lowest surface roughness and thrust force. The recommended optimal cutting parameters were able to reach 0.5177 (μm) and 11.8103 (N) for surface roughness and thrust force using the RUAEG method. [ABSTRACT FROM AUTHOR]

Improving the surface quality of additive manufactured parts like poly lactic acid (+) is an important study that is currently being carried out by researchers. To reach the high-quality, different conventional and nonconventional methods are applied. In this study, the capability of ultrasonic vibration in drilling of an additive manufactured poly lactic acid (+)was examined. The process was implemented in two methods: conventional and vibratory drilling. Then, thrust force and chip type were analyzed, and the effect of them on surface roughness, delamination, circularity, and cylindricality have been investigated. As a result, it was indicated that lower thrust force and broken chips, which were generated in ultrasonic drilling, caused the surface quality parameters to be improved compared to the conventional method. [ABSTRACT FROM AUTHOR]

High quality of machined surfaces is an important requirement in production industries. Therefore, different methods such as ultrasonic vibrations are implemented to improve this parameter. In this study, it is tried to specify some of effective parameters on surface improvement in ultrasonicassisted turning. Accordingly, a series of experiments in the way of conventional and vibratory turning are conducted where surface roughness and surface topography are evaluated as main objectives of this work. Furthermore, analysis of tool wear and radial displacement of tool and workpiece are carried out for explanation of surface enhancement in vibratory turning. As a result, it is shown that generated typical peaks and valleys in conventional turning are flattened and reduced in vibratory turning which is explained by existence of lower radial force. [ABSTRACT FROM AUTHOR]

In this study, the use of ultrasonic peening technology (UPT) on the rolling mill roll graphite steel GSH48 was surveyed in order to improve some surface mechanical and thermal properties. UPT is one of the newest technologies of severe plastic deformation in which vibratory tool strikes the workpiece surface with continual reciprocating motions, resulting in severe plastic deformation on the surface. This method enhances mechanical and thermal properties like fatigue life and thermal fatigue. Thermal fatigue in the rolling mill rolls causes the growth of crack on the surface and growing that in depth leads to the break of the roll. The influence of the UPT on the improvement of thermal fatigue life of the hot-rolling rolls was investigated by conducting thermal fatigue test in which parameters were adjusted in accordance with the process of hot-rolling. By the simulation and manufacturing of peening vibratory tool, preparation of the process was accomplished including setting up the ultrasonic vibratory tool on lathe machine. According to the standard of related devices, samples were prepared form the surface of roll and the examinations of fatigue, thermal fatigue, and surface topology by atomic force microscopy (AFM) were performed on workpieces in different states before and after the UPT process with one, two, and three passes. The process of ultrasonic peening caused severe plastic deformation on surface layers and prevented from crack growth. The results of this research indicated the rise of the fatigue and thermal fatigue life of the pieces after UPT process. [ABSTRACT FROM AUTHOR]

Conventional drilling (CD) which is known by two rotary and linear motions is considerably used in material removal processes; however, this method cannot satisfy the new demands of modern industry anymore, encountering with some serious technological constraints such as fast tool wear, high thrust force, and so on. A new and promising method which has been used recently as an alternative technique to cope or at least diminish common difficulties in CD is imposing ultrasonic vibrations to the cutting process, where vibrations usually with high frequency and low amplitude are superimposed in the movements of cutting tool. This study is a new exercise which considers the effects of one and two directional ultrasonic vibrations in drilling of AISI 1045 compared to CD. In one directional technique known as longitudinal ultrasonic assisted drilling (L UAD), ultrasonic vibrations are added to the feed motion and in two directional vibrations; ultrasonic vibrations are simultaneously applied to both feed and rotary motions known as longitudinal-torsional ultrasonic assisted drilling (L-T UAD). The study which is performed both experimentally and numerically does its best to evaluate and compare the obtained results in CD, L UAD, and L-T UAD. In experimental part, a system including two vibratory tools and a rotary mechanism is designed, fabricated, and then assembled with other equipment on a milling machine to accomplish drilling tests. In numerical part, a FE model is also developed with the aim of further understanding of experimental results, by which drilling operations either conventional or vibratory in different forms can be conducted and studied. As a brief conclusion, it was found that ultrasonic vibrations can be used as an effective tool for enhancement of drilling process and longitudinal-torsional vibrations reveal better results than longitudinal vibrations. [ABSTRACT FROM AUTHOR]

Conventional drilling (CD) which is known by two constant rotary and linear motions causes some problems in drilling of materials such as high thrust force, poor surface quality, and rapid tool wear. To get rid of these problems or at least minimize them, a promising technology has been employed in the recent years, where vibrations usually with low amplitude and high frequency are applied to the direction of feed motion results in a time-dependent velocity between drill tip and workpiece. This paper focuses on the design of a vibratory tool following by experimental and numerical approaches to study the influence of longitudinal ultrasonic vibrations on drilling of aluminum alloy 7075. Experimental part is a comprehensive exercise to design, fabricate, and test a system equipped with different instruments to work in desired conditions. Experimental results are supported by a finite element method to better comprehend what is happening in cutting process when ultrasonic vibrations are added. The achieved results prove that using ultrasonic-assisted drilling (UAD), the machining ability of drilled aluminum workpiece can enhance significantly. Improvement of up to 40% for drill circularity and a reduction of up to 37% in thrust force were achieved. [ABSTRACT FROM AUTHOR]

In this study, influence of added linear vibration of cutting tool on the performance of rotary turning of AISI 4140 steel is investigated. Experimental tests are carried out at different cutting and tool rotary speeds by using special equipment for ultrasonic assisted rotary turning. The results of surface roughness, cutting force, and tool wear obtained during vibratory-rotary cutting are compared by the values of conventional and rotary turning. At the end, it is shown that lower displacement of workpiece in the radial direction, decrease of tool rake angle, and producing cooling cycle during disengagement time in vibration cutting cause lower wear distribution along the circumference of cutting tool. As a consequence to that, a significant reduction in surface roughness and cutting force is observed compared to the conventional and rotary turning. Besides, effect of variations in tool rotary and cutting speeds on output parameters are evaluated. [ABSTRACT FROM AUTHOR]

Studying the effect of longitudinal ultrasonic vibrations on the performance of incremental forming process of aluminum-1050 sheet is the main purpose of this paper. In this new technique, ultrasonic vibrations with high frequency and low amplitude are axially added to the movement of forming tool. To fulfill this purpose, a system was carefully devised. This system consists of different parts including a mechanism attached into the chuck of CNC machine to give rotary motion and also sent ultrasonic power to the vibratory tool. Straight groove test was performed, and various parameters including forming force and sheet formability were investigated in both conventional and ultrasonic-assisted incremental forming process. The achieved results show that ultrasonic assistance can increase formability and decrease forming force significantly. [ABSTRACT FROM AUTHOR]

Laser shock peening (LSP) is known as a post processing surface treatment which can improve the mechanical properties of some materials. Shock waves are generated by confining the laser-induced plasma to cause a large pressure shock wave over a significant surface area. In the present study, effects of LSP on the electrochemical corrosion and micro hardness properties of 316L stainless steel alloy were investigated by changing the laser parameters such as the laser spot size, the average number of impacts, and the laser intensity. Since laser parameters do not cover the desired region of LSP, we have to use the proper design of experiment method, in which the D-optimal design of MATLAB was selected. Results revealed that by increase in irradiance, number of impacts and spot size of laser beam, improvement in the surface micro hardness, and corrosion resistance is achieved. Also, due to unexpected drop into the outcome of our experiments, it was found that the contamination of the transparent overlay and reduction of the absorption coefficient of the absorbent layer play a key role to reduce the efficiency of the mechanical impacts. So, by changing the experimental conditions, even better results are expected. [ABSTRACT FROM AUTHOR]

Beside beneficial aspects of friction stir welding such as solid-state joining process, no melting, no recasting, etc., there are some disadvantages like considerable axial forging force especially for high-strength materials. Researchers have developed several innovative ideas to diminish the process problems. In the present study, to investigate the effect of bending vibrations, an ultrasonic vibratory tool of friction stir welding, in bending mode, has been designed and manufactured. Firstly, the vibratory tool was designed for the operating resonance frequency of 20 KHz in ABAQUS software. This tool consists of transducer, horn, and welding tool. Using the optimal dimensions achieved from the modal analysis, the FSW tool has been manufactured. Then, experimental investigations verify the validity of the tool design process, such as clamping flange position, resonance frequency, and so on. The friction stir welding of aluminum Al6061 and Teflon plates has been done with lathe machine. FSW-assisted ultrasonic vibrations in bending mode show some advantages in comparing with linear mode, such as decreased tool length and increased efficiency of vibrational energy transferring to the tool tip. Finally, with respect to the indicated improvements, reduction and rise of welding forces and temperature have been observed, respectively. [ABSTRACT FROM AUTHOR]

One of the main problems in the machining of thin-walled parts made of high-strength aluminum alloys is distortion and dimensional instability after machining, which leads to an increase in scraped parts and the cost of production. In general, distortion and dimensional instability in machined parts made of aluminum alloy is a function of the residual stresses. In this article, the correlation between machining-induced residual stresses and distortion in a thin-walled work pieces is investigated. Several experiments are carried out under different machining conditions using two carbide and polycrystalline diamond (PCD) tools on a thin-walled cylinder made of AL7075-T6 alloy. Rates of variations in geometrical tolerances and distortion for all work pieces are measured. To study the effect of mechanical and thermal loads on the residual stresses and distortion, the machining force and temperature of cutting area are measured. Finally, the correlation between the residual stress and distortion is studied by measurement of residual stress on some work pieces. Similarly, in order to investigate the effect of work pieces thickness on distortion, several tests are carried out on three work pieces with different thicknesses. The results indicate that the force and temperature have direct effect on the residual stresses and distortion in the thin-walled parts. [ABSTRACT FROM AUTHOR]