Browsing by Author "Akar, S."

Now showing 1 - 4 of 4

Citation - Scopus: 3
Electrochemical discharge machining: trends and development
(Elsevier, 2021) Perveen, A.; Akar, Samet; Akar, S.; 315516; Makine Mühendisliği
The fabrication of microscale products revolutionizes the way manufacturing industries work today and has become the demand of current era due to their applications in various fields like microfluidics, biomedical testing systems, and microelectromechanical systems. Current research interest of manufacturing industries has shifted toward micromanufacturing process development. Electrochemical discharge machining (ECDM) is one of such recently developed process well known for its capability to machine both conductive as well as nonconductive materials. This process evolved from combination of electrodischarge machining and electrochemical machining. This hybrid machining process becomes an attractive technology due to its process simplicity and application in fabrication of microscale features and three-dimensional structures. This chapter will be focusing on the state-of-the-art review of the ECDM processes and its recent development. Various form of this process such as ECDM turning, ECMD-milling, and ECDM grinding will be presented in this chapter. Based on the research found in the literature, limitation associated with ECDM process will be demonstrated, and future research trend for overcoming these drawbacks will be narrated. © 2021 Elsevier Inc. All rights reserved.
Citation - Scopus: 4
Micro-WEDM of Ni55.8Ti shape memory superalloy: Experimental investigation and optimisation
(Inderscience Publishers, 2021) Meshri, H.A.M.; Akar, Samet; Akar, S.; Seyedzavvar, M.; Kiliç, S.E.; 315516; Makine Mühendisliği
Nickel-titanium superalloy has gained significant acceptance for engineering applications as orthotropic implants, orthodontic devices, automatic actuators, etc. Considering the unique properties of these alloys, such as high hardness, toughness, strain hardening, and development of straininduced martensite, micro-wire electro-discharge machining (μ-WEDM) process has been accepted as one of the main options for cutting intricate shapes of these alloys in micro-scale. This paper presents the results of a comprehensive study to address the material removal rate (MRR) and surface integrity of Ni55.8Ti shape memory superalloy (SMA) in the μ-WEDM process. The effects of discharge current, pulse on-time, pulse off-time, and servo voltage on the performance of this process, including MRR, white layer thickness, surface roughness, and micro-hardness of the machined surface, were investigated by multi-regression analysis using response surface methodology (RSM). The optimisation of input parameters based on the gradient and the swarm optimisation algorithms were also conducted to maximise the MRR and minimise the white layer thickness, surface roughness, and micro-hardness of the machined samples. © 2021 Inderscience Enterprises Ltd.. All rights reserved.
Citation - Scopus: 4
Microchannels for microfluidic systems
(Elsevier, 2020) Nasseri, B.; Akar, S.; Naseri, E.; 315516
Microfluidic systems (which are also known as microchannel devices) are an important and versatile practical apparatus applicable in different areas of science and technology. The appropriate design of microfluidic system demands the accurate calculation of the parameters of the microfluidic device. The channels used in microfluidic systems are critical compartments of the device, which affect the efficiency of the system. The purpose of this chapter is to survey the microchannels and their characteristics in microfluidic systems. After a detailed discussion of microchannels, their applications for non-living phantoms for cardiovascular, neuroscience and respiratory studies will be discussed. In the biomedical applications of microchannels the areas such as cell studies e.g. cytoskeleton behavior, cell-to-cell interaction detecting of cell derived moieties are important. Also cellular level tissue engineering, such as cell vaso-occlusion in tissue biomimicking is described. © 2021 Elsevier Inc. All rights reserved.
Citation - Scopus: 1
Numerical simulation and experimental investigation: Metal spinning process of stepped thin-walled cylindrical workpiece
(Murat Yakar, 2022) Seyedzavvar, M.; Akar, Samet; Seyedzavvar, M.; Akar, S.; Abbasi, H.; 315516; Makine Mühendisliği
Many equipment and devices utilized in the aerospace industry are formed as symmetric parts through high plastic deformation of high strength sheet metal alloys with low thickness. Considering the inherent advantages of the spinning process of simple tooling and concentrated deformation loading, this process can be considered as one of the main options in producing these thin-sectioned lightweight parts. In this study, a Finite Element (FE) model has been developed to simulate the formation of a stepped thin-walled cylindrical workpiece of AISI 316 stainless steel alloy by spinning process. The FE simulation results were employed to investigate the effects of process parameters, including feed rate of the roller and rotational velocity of the mandrel on the distribution of stress and strain in the sheet metal, wrinkling failure, and thinning of the sheet metal during deformation. Experiments were carried out using selective input parameters based on the results of FE simulations. The comparison between FE simulations and experiments revealed that the developed model could predict the thinning of the sheet metals with over 93 % accuracy. Additionally, a good agreement between the experimentally deformed sheet configurations with those resulting from finite element simulations has been observed. © Author(s) 2022.