Selection of parameters for advanced machining processes using firefly algorithm

AbstractAdvanced machining processes (AMPs) are widely utilized in industries for machining complex geometries and intricate profiles. In this paper, two significant processes such as electric discharge machining (EDM) and abrasive water jet machining (AWJM) are considered to get the optimum values of responses for the given range of process parameters. The firefly algorithm (FA) is attempted to the considered processes to obtain optimized parameters and the results obtained are compared with the results given by previous researchers. The variation of process parameters with respect to the responses are plotted to confirm the optimum results obtained using FA. In EDM process, the performance parameter “MRR” is increased from 159.70gm/min to 181.6723gm/min, while “Ra” and “REWR” are decreased from 6.21μm to 3.6767μm and 6.21% to 6.324×10−5% respectively. In AWJM process, the value of the “kerf” and “Ra” are decreased from 0.858mm to 0.3704mm and 5.41mm to 4.443mm respectively. In both the processes, the obtained results show a significant improvement in the responses

Hybrid artificial fish and glowworm swarm optimization algorithm for electrical discharge machining of titanium alloy

Electrical discharge machining (EDM) is a non-traditional machining process widely used to machine geometrically complex and hard materials. In EDM, selection of optimal EDM parameters is important to have high quality products and increase productivity. However, one of the major issues is to obtain better machining performance at optimal value of these machining parameters. Modelling and optimization of EDM parameters have been considered to identify optimal EDM parameters that would lead to better EDM performance. Due to the complexity and uncertainty of the machining process, computational approaches have been implemented to solve the EDM problem. Thus, this study conducted a comprehensive investigation concerning the influence of EDM parameters on material removal rate (MRR), surface roughness (Ra) and dimensional accuracy (DA) through an experimental design. The experiment was performed based on full factorial design of experiment (DOE) with added center points of pulse on time (Ton), pulse off time (Toff), peak current (Ip) and servo voltage (Sv). In the EDM optimization, glowworm swarm optimization (GSO) algorithm was implemented. However, previous works indicated that GSO algorithm has always been trapped in the local optima solution and is slow in convergence. Therefore, this study developed a new hybrid artificial fish and glowworm swarm optimization (AF-GSO) algorithm to overcome the weaknesses of GSO algorithm in order to have a better EDM performance. For the modeling process, four types of regression models, namely multiple linear regression (MLR), two factor interaction (2FI), multiple polynomial regression (MPR) and stepwise regression (SR) were developed. These regression models were implemented in the optimization process as an objective function equation. Analysis of the optimization proved that AF-GSO algorithm has successfully outperformed the standard GSO algorithm. 2FI model of AF-GSO optimization for MRR and DA gave optimal solutions of 0.0042g/min and 0.00129%, respectively. On the other hand, the SR model for Ra of AF-GSO optimization gave the optimal solution of 1.8216p,s. Overall, it can be concluded that AF-GSO algorithm has successfully improved the quality and productivity of the EDM problems

Формування комбінованих Nb, Co, Ti, С покриттів на поверхні інструментальної сталі ХВГ методом електроіскрового легування

Об'єкт досліджень: покриття, сформовані електроіскровим легуванням електродами Nb, Co, С, Ti на поверхні сталі ХВГ. Мета досліджень: дослідити вплив послідовності електроіскрової обробки електродами Nb, Co, С, Ti поверхні сталі ХВГ на мікроструктуру, мікротвердість та рентгенофазовий аналіз покриттів, сформованих такою обробкою. Методи досліджень і апаратура: - гравіметричний аналіз проведений з використанням електронних лабораторних вагів «AXISAD 50» під час проведення ЕІЛ на установці “ ЕЛІТРОН– 26А ”; - мікроструктурний аналіз проведений з використанням оптичного мікроскопу МЕТАМ РВ -21; - мікродюрометричний аналіз проведений з використанням мікротвердоміру ПМТ-3М; - рентгеноструктурні дослідження проведено з використанням дифрактометру RIGAKU-ULTIMA IV. Практичне значення: проведений аналіз експериментальних даних може бути використаний для покращення якості або відновлення поверхні виробів зі сталі ХВГ та забезпечення їх довготривалої експлуатації.Object of research: coatings formed by electrospark alloying with Nb, Co, C, Ti electrodes on the surface of 107WCR5 steel. The purpose of the research: to investigate the effect of the sequence of electrospark treatment with Nb, Co, C, Ti electrodes of the surface of 107WCR5 steel on the microstructure, microhardness and X-ray phase analysis of the coatings formed by such treatment. Research methods and equipment: - gravimetric analysis carried out using electronic laboratory scales "AXISAD 50" during EIL at the "ELYTRON-26A" installation; - microstructural analysis was carried out using a METAM RV-21 optical microscope; - microdurometric analysis was carried out using a PMT 3M microhardness tester; - X-ray structural studies were carried out using a RIGAKU-ULTIMA IV diffractometer. Practical significance: the conducted analysis of experimental data can be used to improve the quality or restore the surface of 107WCR5 steel products and ensure their long-term operation

Applications of optimization techniques for parametric analysis of non-traditional machining processes: A Review

The constrained applications of conventional machining processes in generating complex shape ge-ometries with the desired degree of tolerance and surface finish in various advanced engineering materials are being gradually compensated by the non-traditional machining (NTM) processes. These NTM processes usually have higher procurement, maintenance, operating and tooling cost. Hence, in order to attain their maximum machining performance, they are usually operated at their optimal or near optimal parametric settings which can easily be determined by the application of dif-ferent optimization techniques. In this paper, 133 international research papers published during 2012-16 on parametric optimization of NTM processes are extensively reviewed to have an idea on the selected process parameters, observed responses, work materials machined and optimization techniques employed in those processes while generating varying part geometries for their industrial use. It is observed that electro discharge machining is the mostly employed NTM process, applied voltage is the identified process parameter with maximum importance, surface roughness and material removal rate are the two maximally preferred responses, different steel grades are the mostly machined work materials and grey relational analysis is the most popular tool utilized for para-metric optimization of NTM processes. These observations would help the process engineers to attain the machining performance of the NTM processes at their fullest extents for different work material and shape feature combinations