Dynamic Analysis of the Ultrasonic Machining Process

1996 ◽  
Vol 118 (3) ◽  
pp. 376-381 ◽  
Author(s):  
Z. Y. Wang ◽  
K. P. Rajurkar

This paper presents a dynamic analysis of the ultrasonic machining process based on impact mechanics. Equations representing the dynamic contact force and stresses caused by the impinging of abrasive grits on the work, are obtained by solving the three-dimensional equations of motion. The factors affecting the material removal rate have been studied. It is found that the theoretical estimates obtained from the dynamic model are in good agreement with the experimental results.

Author(s):  
Judong Shen ◽  
Z. J. Pei ◽  
E. S. Lee

Rotary ultrasonic machining (RUM) is one of the cost-effective machining methods for machining difficult to process material. It is a hybrid machining process that combines the material removal mechanisms of diamond grinding with ultrasonic machining. However, due to the lack of understanding of the mechanisms of these operations, models for these machining processes are difficult to establish. In this paper, the support vector fuzzy adaptive network (SVFAN), a parameter free nonlinear regression technique, is used to model the material removal rate in RUM. The SVFAN retains the advantages of both the fuzzy adaptive networks and the support vector machines. The former possesses the linguistic representation ability and the latter is a very effective learning machine. The results are compared with that obtained by the use of fuzzy adaptive network and it is shown that the combined approach is a more effective algorithm for the modeling of complex manufacturing processes.


Author(s):  
Z. Yu ◽  
X. Hu ◽  
K. P. Rajurkar

As a micro mechanical machining process, micro ultrasonic machining (micro USM) has the major advantage of producing micro-scale components or features in brittle (glass, quartz crystal, and sapphire) and hard (ceramics) materials. Micro USM is used to generate micro holes with 5μm in diameter and 3D micro cavities. However, the relationship of machining parameters such as static load, abrasive particle and amplitude of vibration and the material removal rate is not clearly understood. In this paper, a mathematical model is developed to describe the material removal process in micro USM. Experiments were carried out to verify the model. It was found that the machining speed decreases when the load is over a certain value, which is different from that of theoretical model. To understand this phenomenon, a simple model was proposed to analyze it qualitatively. It was found that the debris accumulation around the crater in a short time is the main reason resulting in the low machining efficiency.


2006 ◽  
Vol 532-533 ◽  
pp. 361-364 ◽  
Author(s):  
Wei Min Zeng ◽  
Xi Peng Xu ◽  
Zhi Jian Pei

Rotary ultrasonic machining (RUM) is one of the cost-effective machining methods for advanced ceramics, which is a hybrid machining process that combines the material removal mechanisms of diamond grinding and ultrasonic machining (USM). This paper presents an overview of the investigations on RUM of advanced ceramics. The issues about the material removal mechanisms, process modeling, material removal rate, and tool wear in RUM are reviewed. Directions of future research on RUM are also presented.


Author(s):  
Gurpreet Singh ◽  
DR Prajapati ◽  
PS Satsangi

The micro-electrical discharge machining process is hindered by low material removal rate and low surface quality, which bound its capability. The assistance of ultrasonic vibration and magnetic pulling force in micro-electrical discharge machining helps to overcome this limitation and increase the stability of the machining process. In the present research, an attempt has been made on Taguchi based GRA optimization for µEDM assisted with ultrasonic vibration and magnetic pulling force while µEDM of SKD-5 die steel with the tubular copper electrode. The process parameters such as ultrasonic vibration, magnetic pulling force, tool rotation, energy and feed rate have been chosen as process variables. Material removal rate and taper of the feature have been selected as response measures. From the experimental study, it has been found that response output measures have been significantly improved by 18% as compared to non assisted µEDM. The best optimal combination of input parameters for improved performance measures were recorded as machining with ultrasonic vibration (U1), 0.25 kgf of magnetic pulling force (M1), 600 rpm of tool rotation (R2), 3.38 mJ of energy (E3) and 1.5 mm/min of Tool feed rate (F3). The confirmation trail was also carried out for the validation of the results attained by Grey Relational Analysis and confirmed that there is a substantial improvement with both assistance applied simultaneously.


1995 ◽  
Vol 117 (2) ◽  
pp. 142-151 ◽  
Author(s):  
Z. J. Pei ◽  
D. Prabhakar ◽  
P. M. Ferreira ◽  
M. Haselkorn

An approach to modeling the material removal rate (MRR) during rotary ultrasonic machining (RUM) of ceramics is proposed and applied to predicting the MRR for the case of magnesia stabilized zirconia. The model, a first attempt at predicting the MRR in RUM, is based on the assumption that brittle fracture is the primary mechanism of material removal. To justify this assumption, a model parameter (which models the ratio of the fractured volume to the indented volume of a single diamond particle) is shown to be invariant for most machining conditions. The model is mechanistic in the sense that this parameter can be observed experimentally from a few experiments for a particular material and then used in prediction of MRR over a wide range of process parameters. This is demonstrated for magnesia stabilized zirconia, where very good predictions are obtained using an estimate of this single parameter. On the basis of this model, relations between the material removal rate and the controllable machining parameters are deduced. These relationships agree well with the trends observed by experimental observations made by other investigators.


2017 ◽  
Vol 107 (09) ◽  
pp. 674-680
Author(s):  
E. Prof. Abele ◽  
C. Hasenfratz ◽  
C. Praetzas ◽  
G. M. Schüler ◽  
C. Stark ◽  
...  

Die Herstellung von Verdichterscheiben stellt hohe Ansprüche an die Fertigungstechnik. Neue, schwer zu zerspanende Materialien und Integralkonstruktionen erzeugen eine hohe Komplexität bei der Ausführung. Das Projekt „SchwerSpan“ stellt sich dieser Herausforderung und entwickelt einen Prozess zur Schruppfräsbearbeitung von Verdichterscheiben. Ziel des Projekts ist eine Reduktion der Werkzeugkosten bei erhöhtem Zeitspanvolumen.   The production of compressor disks places high demands on the manufacturing technology. A very complex task is created by new difficult-to-cut materials and integral components. The project “SchwerSpan” is taking on this task by developing a machining process for rough milling in the production of compressor disks. The aim of the process is to reduce the tool costs by increasing material removal rate.


Author(s):  
Sagil James ◽  
Sharadkumar Kakadiya

Shape Memory Alloys are smart materials that tend to remember and return to its original shape when subjected to deformation. These materials find numerous applications in robotics, automotive and biomedical industries. Micromachining of SMAs is often a considerable challenge using conventional machining processes. Micro-Electrical Discharge Machining is a combination of thermal and electrical processes, which can machine any electrically conductive material at micron scale independent of its hardness. It employs dielectric medium such as hydrocarbon oils, deionized water, and kerosene. Using liquid dielectrics has adverse effects on the machined surface causing cracking, white layer deposition, and irregular surface finish. These limitations can be minimized by using a dry dielectric medium such as air or nitrogen gas. This research involves the experimental study of micromachining of Shape Memory Alloys using dry Micro-Electrical Discharge Machining process. The study considers the effect of critical process parameters including discharge voltage and discharge current on the material removal rate and the tool wear rate. A comparison study is performed between the Micro-Electrical Discharge Machining process with using the liquid as well as air as the dielectric medium. In this study, microcavities are successfully machined on shape memory alloys using dry Micro-Electrical Discharge Machining process. The study found that the dry Micro-Electrical Discharge Machining produces a comparatively better surface finish, has lower tool wear and lesser material removal rate compared to the process using the liquid as the dielectric medium. The results of this research could extend the industrial applications of Micro Electrical Discharge Machining processes.


2017 ◽  
Author(s):  
K. L. Tan ◽  
S. H. Yeo

Non-contact ultrasonic abrasive machining (NUAM) is a variant of ultrasonic machining (USM). In NUAM, material is removed predominantly by cavitation erosion in abrasive slurry. Due to a significantly lower material removal rate than traditional USM, NUAM is investigated for its applicability on surface modification and finishing in this study. Experiments were conducted on SUS304 steel samples machined by wire electrical discharged machining (WEDM). Due to the thermal spark phenomenon during WEDM, a thermal recast layer, of thickness approximately 15 μm, is often left over on the specimen’s surface after the process. The undesired thermal recast layer contributes to the poor surface integrity of specimens. A NUAM system was configured using a 40 kHz ultrasonic system. Ultrasonic vibration amplitude of 70 μm at the horn tip was used to generate cavitation bubbles in the abrasive slurry. NUAM was found to be effective in removing the unstable thermal recast layers by means of cavitation erosion. As a result, the average surface roughness, Ra, of the specimens improved from approximately 2.5 μm to ∼1.7 μm after 20 minutes of processing time. Furthermore, the addition of abrasive particles was observed to aid in more efficient removal of thermal recast layers than a pure cavitation condition.


2019 ◽  
Vol 814 ◽  
pp. 127-131
Author(s):  
Patittar Nakwong ◽  
Apiwat Muttamara

Wire electrical discharge machine (WEDM) is non-conventional machining process. It can be used for hard cutting material. The study has been presented the combining WEDM with an ultrasonic machine (USM) with brass and tungsten were used as a wire electrode and workpiece respectively. The experiment was carried out with an ultrasonic transducer at 40, 80 kHz. The results were observed with the material removal rate (MRR) and surface roughness (Ra). This research introduced the method of USM setup and described the effected of vibration with the wire electrode on the displacement of amplitude. The result shows that the WEDM process with USM at 40 kHz can be more improved with the material removal rate and surface roughness than that of USM at 80 kHz. This can be explained that higher frequency affected to vibration displacement which makes lower amplitude.


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