Advanced Materials Research Vols. 984-985

Abstract: In this work the significance of important parameters such as Blank temperature, Blank hold force on limiting drawing ratio (LDR) of IS513 CR3 steel sheets during warm deep drawing was determined. Influence of these parameters was analyzed at three different forming speeds. Experimental results proved that the blank temperature has a higher influence on LDR compared with other parameters especially at low forming speed.

Abstract: Deep-hole drilling is a process in which the hole length will be very high when compared to diameter of the drill hole (i.e. length to diameter ratio will be greater than 5). Drilling a deep hole with very high accuracy is difficult process. The current project is about the production of deep hole with the aim to produce a chip which is not a continuous chip and also not a powdery chip. These conditions can be attained by varying the spindle speed and the tool feed rate.

Abstract: Micro-EDM is an extensively used machining process for the fabrication of micro-holes with various advantages resulting from its characteristics of non-contact and thermal process. In this micro-fabrication technique, processing parameters greatly affect processing efficiency and stability. An experimental investigation on die-sinking Micro-EDM of EN-24 die steel using various electrodes such as tungsten, copper, copper tungsten and silver tungsten has been carried out. The present study aims to assess the quality and accuracy of the produced micro-holes, machining stability, material removal rate (MRR), tool wear ratio (TWR), surface roughness (Ra), Heat affected zone (HAZ) and overcut (OC). In addition, the influence of gap voltage, capacitance and discharge energy on the performance of the process has also been investigated. Experimental results proved that the overall performance of the copper electrode is found to be optimum with high MRR, thin HAZ though copper shows higher TWR, surface roughness and overcut.

Abstract: On-line monitoring of tool wear in turning is vital to increase machine utilization as scrapped components, machine tool breakage and unscheduled downtime result from worn tool usage cause huge economic loss. Several techniques have been developed for monitoring wear levels on the cutting tool on-line. Keeping in to account the difficulties encountered during the implementation of tool condition monitoring (TCM). The signal acquisition is one of the key elements used during the implementation of TCM. This paper provides an in depth coverage of various signal acquisition methods used in TCM.

Abstract: Experimental study on moisture absorption of solid clay based desiccant mould with varying void fraction is presented in this work. Solid desiccant moulds of three types by varying void fraction with the composition of 10% cement, 10% of calcium chloride, 20% vermiculite with particle size of 5mm and above and 60% of bentonite were prepared and tested under uniform conditions in the drying chamber. The results show that the moisture absorption capacity of the mould is significantly affected when the void fraction is changed.

Abstract: Multi-tool turning process employs more than one cutting tool for machining the work piece simultaneously. In the conventional turning process, effect of machining parameters over cutting forces, vibration, work piece surface finish and dimensional tolerances have been discussed in detail, however no attempt has been made in the multi-tool turning process. Cutting tool vibration is very important as it reveals the condition of cutting tool as well as work piece quality. In this study, a second cutting tool is introduced at the rear side of the lathe with some distance from conventional front cutting tool to machine the work piece simultaneously. Accelerometers are used to measure the vibration signals in the tangential direction of cutting. Obtained time domain vibration signals are converted to frequency domain signals by Fast Fourier Transform to reveal its power spectral density. In this work cutting speed and distance between front and rear cutting tool are varied to understand the cutting tool vibration. With increase in cutting speed and increase in distance between front and rear cutting tool, vibration reduces.

Abstract: In this research article aims to develop a heuristic for minimizing the total material processing time and idle time of the critical machine in a flow shop. This heuristic is proposed through the Exponential Distribution (ED) factor which helps in developing a mathematical model with less computational instance. When the idle time of the critical machine is reduced then it is indirectly affects the total material processing time of the flow shop, which makes the objective of critical machine utilization as vital. And a set of constrain had been established to position the critical machines in the flow shop. For several instance, computational experiments had done using the benchmark problems, among other heuristics ED heuristic yields a better result.

Abstract: A Flexible Manufacturing System (FMS) is an integrated, computer-controlled system of machines, automated handling systems, and storage systems that can be used to simultaneously manufacture a variety of jobs. FMSs can be characterized as asynchronous, concurrent, distributed and parallel systems in which multiple operations share multiple resources so that the performance criteria are optimized. Petri nets (PNs) have recently become a promising approach for modeling FMSs. PNs are formal graphical modeling tool that can be efficiently utilized as a process analysis and modeling tool, because it shows graphically and dynamically to simulate a process in an integrated manner. It is a mathematical modeling technique that is useful for modeling concurrent, asynchronous, distributed, parallel, nondeterministic, and stochastic systems. Unreasonably the dispatching resources/jobs to machine in FMS may result in a deadlock situation and the situation is studied thoroughly and avoided through PN techniques. From the design and analysis point of view, the uses of nets have many advantages in modeling, performance evaluation, qualitative analysis and code generation. Scheduling a manufacturing system is usually a Non-Polynomial hard problem. This means that only heuristic algorithms can be used to provide near-optimal schedule when it is merged with PN. The merging of PNs with knowledge based heuristic techniques seems to be very promising to deal with large complex discrete event dynamic systems. This paper presents a comprehensive survey of FMS that combines PNs with other methods.

Abstract: In this study, the response surface methodology was used to optimize the process parameters of constant speed horizontal spindle surface grinding. The experiments were conducted based on the design expert software. The surface roughness characteristics were investigated in AISI 1080 steel plates using A60V5V grinding wheels. The optimum parameters for minimum surface roughness were found using Design Expert software. The parameters for a particular surface roughness value can also be determined using the results of this experiment. This results shows that feed has a greater effect on surface roughness and feed has medium effect on surface roughness. While dressing depth of cut has a very minimal effect on surface roughness.

Abstract: In this study AZ31B Mg alloy is developed by powder metallurgy route followed by hot extrusion. The extruded materials were characterized for microstructure, X-ray diffraction (XRD), density, porosity and mechanical properties such as tensile, compression, impact and micro hardness. The SEM analysis of fractured surface of AZ31B Mg alloy showed quasi-cleavage fracture mode.