Emrecan Soylemez

Istanbul Technical University · Department of Mechanical Engineering

Purpose This study aims to develop a novel thermal modeling strategy to simulate electron beam powder bed fusion at part scale with machine-varying process parameters strategy. Single-bead and part-scale experiments and modeling were studied. Scanning strategies were described by the process controlling functions that enabled modeling. Design/meth...

Additive manufacturing offers the advantage of producing parts layer by layer, enabling the creation of intricate geometries with shorter production times. These benefits provide an opportunity to manufacture complex-shaped microwave technology parts, such as waveguides and radio frequency (RF) filters, which are conventionally difficult, costly, o...

Particle dampers (PD), a passive damping technology, absorb energy from particle-particle and particle-cell wall interactions originating from friction and collision. PDs offer advantages such as design simplicity, low cost, applicability in harsh conditions, and flexibility to be used in a wide frequency band range. Additive manufacturing, specifi...

Laser direct structuring (LDS) is critical in the integration of circuits onto 3D‐shaped plastic parts, such as antennas and radio frequency components. The LDS process encompasses three stages: deposition of 3D parts, laser structuring, and metallization. While laser‐direct structurable parts have been manufactured through plastic injection moldin...

This study investigates the impact of capillary adhesion force on the green part density in metal powder binder jetting 3D printing. Gas atomized Co-Cr-Mo, SS316L, and pure Cu powders were used to print various samples. The printed samples were then treated with water, 1-Hexanol, and n-Amyl alcohol vapor for 24 hours to nucleate capillary bridges b...

Electron Beam Melting (EBM) is one of the challenging additive manufacturing processes for thermal modelling due to varying unknown process parameters. Understanding how the primary process parameters, such as scan speed and scan power, are controlled by beam control functions during manufacturing is essential for accurate thermal modelling of the...

Binder jet additive manufacturing is a viable method that can be used with a variety of materials, such as metals and ceramics, and offer higher speed and reduced cost for high-volume production compared to powder bed fusion printing. However, the true potential of binder jet additive manufacturing has yet to be realized due to a significant knowle...

Degradation of powder feedstock characteristics in Electron Beam Melting (EBM) may have detrimental effect on the final performance of the produced components. The ability to reuse the powder in EBM as well as other powder bed fusion processes for metals is a very critical advantage for cost-effectiveness. However, ensuring that the degradation of...

Electron Beam Melting (EBM) is an additive manufacturing (AM) method suitable to process a wide range of alloys in an effective manner due to its high power density and considerably high scan rates in comparison to other metal AM processes. However, a significant level of expertise is necessary to establish this process for demanding industrial app...

Selective laser melting (SLM) is one of the most frequently employed metal additive manufacturing methods. Various industries such as aerospace, automotive, biomedical, and tooling utilize SLM parts. Although it has a wide scope of applications, it demands a thorough understanding to supply reliable parts. Thus, process simulations are key methods...

Selective laser melting (SLM) is a commonly used powder bed fusion metal additive manufacturing (AM) process. Although SLM is preferred due to its near-net-shape part commitment, the deposition rate of this process is slower compared with alternative metal processes. A higher deposition rate of SLM can be obtained by increasing the laser scanning v...

Spacer fabric attracts considerable attention from textile industry due to its advantageous properties compared to conventional fabrics. It has two outer layer that is formed with multifilaments (knitted substrates), and spacer yarns (monofilaments) connect between the substrates. Therefore, it provides good thermal and humidity control. Shoes, bac...

Selective laser melting process has been widely studied to elucidate the effects of process parameters (laser speed, laser power, scan strategy, hatch distance, layer thickness, etc.) on the manufactured parts. Experimental and numerical modeling studies have been investigating the melt pool shapes of the laser sintered layers to correlate the melt...

Selective laser melting is one of the most extensively used metal additive manufacturing method. Although many industries adopt the method, it requires a comprehensive insight to produce reliable parts. Therefore, process monitoring and process simulations are key methods to optimize the process and to reduce the product development time. This stud...

Capillary bridge formation between adjacent surfaces in humid environments is a ubiquitous phenomenon. It strongly influences tribological performance with respect to adhesion, friction and wear. Only a few studies, however, assess effects due to capillary dynamics. Here we focus on how capillary bridge evolution influences crack healing rates. Exp...

Spontaneous crack healing due to van der Waals forces is an important phenomenon in diverse areas such as precision assembly, locomotion, soft robotics, and micro- and nanomachines. For rough surfaces that can be described as a collection of asperities, parallel plate models are used to gain insight into the adhesion values. A single adhesion value...

Insulated rail joints are used for signal control and detection of broken rails in railway operations. Bonded insulated rail joints are the standard in freight railroads with heavy axle loads. While there have been many numerical and experimental studies investigating the mechanics of insulated rail joints, mechanisms to understand the impact failu...

The crack healing rates of polycrystalline silicon microcantilevers in contact with a substrate are measured in n-pentanol vapor at different partial pressures, p/p s. The absolute value of the slope of the logarithmic average crack healing velocity \(\bar{v}\) versus the energy release rate G, \(|d[\log (\bar{v})]/dG|\) , is constant and decreases...

A microcantliever based crack healing experiment is described and utilized in order to study the capillary nucleation rate for typical MEMS surfaces. An advanced test chamber that allows exquisite environmental control is also described and used in this study. Crack healing experiments prove to be a viable experimental technique to investigate the...

Capillary forces are important in nature (granular materials, insect locomotion) and in technology (disk drives, adhesion). Although well studied in equilibrium state, the dynamics of capillary formation merit further investigation. Here, we show that microcantilever crack healing experiments are a viable experimental technique for investigating th...

It is well known that the environment in which micromechanical systems operate significantly affects their performance. It is, therefore, important to characterize micromachine behavior in environments where the humidity, pressure, and chemical composition of the ambient can be precisely controlled. Achieving such a level of environmental control p...

Methods to supply fresh water are becoming increasingly critical as the world population continues to grow. Small-diameter hazardous microbes such as viruses (20-100 nm diameter) can be filtered by size exclusion, but in this approach the filters are fouled. Thus, in our research, we are investigating an approach in which filters will be reusable....

This paper gives an overview of work by the authors developing process mapping methods for additive manufacturing (AM), capturing the dependence of melt pool geometry and microstructure on primary processing variables under steady-state and transient conditions. This work is being applied to the task of process qualification and is being applied ac...

Electron beam-based additive manufacturing processes are being seriously considered for manufacturing and repair applications in the aerospace industry. To be successful, these processes must work over a wide range of material deposition rates to combine affordability (requiring high deposition rates) with the ability to precisely deposit fine geom...