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Öğe A comparative study on the microstructure, mechanical properties, wear and corrosion behaviors of SS 316 austenitic stainless steels manufactured by casting and WAAM technologies(Elsevier, 2023) Gurol, Ugur; Kocaman, Engin; Dilibal, Savas; Kocak, MustafaReplacing the traditional casting method with wire arc additive manufacturing (WAAM) to produce complex shaped parts will lead to using cost-effective technology even for challenging engineering applications depending on their geometry and number of the parts to be produced. This work performed a comparative study on the stainless steel 316 parts manufactured by WAAM and sand casting to reveal the microstructural, mechanical, wear, and corrosion behaviors. The WAAM components were manufactured using three different cooling dwell times and compared in terms of microstructures with the as-cast and heat-treated cast parts to reveal the properties of the WAAM parts. It was concluded that WAAM is a viable engineering alternative to the casting technology. Results showed that the WAAM and cast parts revealed similar microstructures, including delta ferrite and austenite phases, but the cast parts had a coarser grain and lower amount of delta ferrite due to slower cooling during the solidification. The yield and tensile strength of WAAM parts showed an increasing trend with the increase in dwell time, and on average, their yield strength was similar to 1.5 times higher than in cast parts due to the smaller grains and more elevated delta-ferrite content resulting from rapid cooling. Furthermore, the greatest wear resistance was obtained in the cast parts after solution annealing heat treatment followed by water quenching. In contrast the highest corrosion resistance was obtained from WAAM parts produced using a dwell time of 120 sec. In conclusion, WAAM technology can be an excellent alternative to casting technology for producing stainless-steel parts with optimized process parameters.Öğe A novel design on polymeric material recycling technology(Univ Estadual Maringa, Pro-Reitoria Pesquisa Pos-Graduacao, 2021) Tanriver, Kursat; Dilibal, Savas; Sahin, Haydar; Kentli, AykutThe necessity for recycling of wastes has increased nowadays and there are various solutions according to the types of wastes which are presented accordingly. By observing these solutions, the recycling system from the waste collection and separation system of the long-term disappearing of polymer waste to the additive manufacturing design stage has been indicated. Waste collection and separation systems have been reviewed and systems to be used effectively in the systematic way have been exemplified. Among four different separating systems which are with rotating, rail and fixed containers, fixed container four-sorting waste separation systems were chosen and developed as a mechatronic system design. The mechatronic system design is very prominent in order to create efficient and economical mechanisms in fixed-container four-sorting waste separation collection system (FCWS) applications. In addition, physical mechatronic system design (MSD), mechanical design, material selection, electrical electronic design sub-heading and cost analysis were made. In this study, the necessity and importance of the waste separation plants are revealed.Öğe Additively Manufactured Custom Soft Gripper with Embedded Soft Force Sensors for an Industrial Robot(Korean Soc Precision Eng, 2021) Dilibal, Savas; Sahin, Haydar; Danquah, Josiah Owusu; Emon, Md Omar Faruk; Choi, Jae-WonSoft robotic grippers are required for power grasping of objects without inducing damage. Additive manufacturing can be used to produce custom-made grippers for industrial robots, in which soft joints and links are additively manufactured. In this study, a monoblock soft robotic gripper having three geometrically gradient fingers with soft sensors was designed and additively manufactured for the power grasping of spherical objects. The monoblock structure design reduces the number of components to be assembled for the soft gripper, and the gripper is designed with a single cavity to enable bending by the application of pneumatic pressure, which is required for the desired actuation. Finite element analysis (FEA) using a hyperelastic material model was performed to simulate the actuation. A material extrusion process using a thermoplastic polyurethane (TPU) was used to manufacture the designed gripper. Soft sensors were produced by a screen printing process that uses a flexible material and ionic liquids. The grasping capability of the manufactured gripper was experimentally evaluated by changing the pneumatic pressure (0-0.7 MPa) of the cavity. Experimental results show that the proposed monoblock gripper with integrated soft sensors successfully performed real-time grasp detection for power grasping.Öğe Anthropomorphic finger antagonistically actuated by SMA plates(Iop Publishing Ltd, 2015) Engeberg, Erik D.; Dilibal, Savas; Vatani, Morteza; Choi, Jae-Won; Lavery, JohnMost robotic applications that contain shape memory alloy (SMA) actuators use the SMA in a linear or spring shape. In contrast, a novel robotic finger was designed in this paper using SMA plates that were thermomechanically trained to take the shape of a flexed human finger when Joule heated. This flexor actuator was placed in parallel with an extensor actuator that was designed to straighten when Joule heated. Thus, alternately heating and cooling the flexor and extensor actuators caused the finger to flex and extend. Three different NiTi based SMA plates were evaluated for their ability to apply forces to a rigid and compliant object. The best of these three SMAs was able to apply a maximum fingertip force of 9.01N on average. A 3D CAD model of a human finger was used to create a solid model for the mold of the finger covering skin. Using a 3D printer, inner and outer molds were fabricated to house the actuators and a position sensor, which were assembled using a multi-stage casting process. Next, a nonlinear antagonistic controller was developed using an outer position control loop with two inner MOSFET current control loops. Sine and square wave tracking experiments demonstrated minimal errors within the operational bounds of the finger. The ability of the finger to recover from unexpected disturbances was also shown along with the frequency response up to 7 rad s(-1). The closed loop bandwidth of the system was 6.4 rad s(-1) when operated intermittently and 1.8 rad s(-1) when operated continuously.Öğe Characterization of a low-alloy steel component produced with wire arc additive manufacturing process using metal-cored wire(Walter De Gruyter Gmbh, 2022) Gurol, Ugur; Dilibal, Savas; Turgut, Batuhan; Kocak, MustafaIn this study, a low-alloy steel component was manufactured using specially produced E70C-6M class of metal-cored welding wire according to AWS A5.18 standard for the WAAM process. The manufactured low-alloy steel component was first subjected to radiographic examination to detect any weld defect. Uniaxial tensile tests were conducted for the bottom, middle and upper regions. The micro-hardness tests were performed parallel to the deposition direction. The results show that microstructures varied from base metal to the face region of the WAAM component, including the bottom, middle and top sections. The bottom region showed lamellar structures; the middle and upper region presented equiaxed ferrite structure with a small amount of grain boundary pearlites and the face region displayed a mix of equiaxed and lamellar structures of ferrites. The yield and ultimate tensile strengths of the top, middle, and bottom regions exhibited similar results varying between 370 MPa and 490 MPa, respectively. In contrast, the top region showed an elongation value about 15% higher than other regions. Moreover, the yield and ultimate tensile strength for WAAM-produced component were found to be 14% and 24% lower than the multiple-pass all-weld metal of E70C-6M class of metal-cored wire.Öğe Characterization of energy dissipative cushions made of Ni-Ti shape memory alloy(Iop Publishing Ltd, 2022) Gullu, Ahmet; Danquah, Josiah Owusu; Dilibal, SavasEarthquake-resistant design of structures requires dissipating seismic energy by deformations of structural members or additional fuse elements. Owing to its easy-to-produce, plug-and-play, high equivalent damping ratio, and large displacement capacity characteristics, energy dissipative steel cushions (SCs) were found to be an efficient candidate for this purpose. However, similar to other conventional metallic dampers, residual displacement after a strong shaking is the most notable drawback of the SCs. In this work, cushions produced from Ni-Ti shape memory alloy (SMA) are evaluated numerically by experimentally verified finite element models to assess their impact on the performance of earthquake-resistant structures. Furthermore, a reinforced concrete testing frame is retrofitted with energy dissipative steel and Ni-Ti cushions. Performance of the frames (e.g. dissipated energy by the cushions, hysteretic energy to input energy ratio, maximum drift, and residual drift) with different types of cushions are evaluated by nonlinear response history analyses. The numerical results showed that the SCs are effective to reduce peak responses, while Ni-Ti cushions are more favorable to reduce residual drifts and deformations. Hence, a hybrid system, employing the steel and SMA cushions together, is proposed to reach optimal seismic performance.Öğe Characterization of Ni-Ti Alloy Powders for Use in Additive Manufacturing(Pleiades Publishing Inc, 2018) Altug-Peduk, Gozde S.; Dilibal, Savas; Harrysson, Ola; Ozbek, Sunullah; West, HarveyAdditive manufacturing (AM) offers a fully integrated fabrication solution within many engineering applications. Particularly, it provides attractive processing alternatives for nickel-titanium (Ni-Ti) alloys to overcome traditional manufacturing challenges through layer by layer approach. Among powder-based additive manufacturing processes, the laser beam melting (LBM) and the electron beam melting (EBM) are two promising manufacturing methods for Ni-Ti shape memory alloys. In these methods, the physical characteristics of the powder used as raw material in the process have a significant effect on the powder transformation, deposition, and powder-beam interaction. Thus, the final manufactured material properties are highly affected by the properties of the powder particles. In this study, the Ni - Ti powder characteristics are investigated in terms of particle size, density, distribution and chemical properties using EDS, OM, and SEM analyses in order to determine their compatibility in the EBM process. The solidification microstructure, and after built microstructure are also examined for the gas atomized Ni-Ti powders.Öğe Experimental and numerical analysis for improving the suction capacity of the manufactured water jet ejectors(Jve Int Ltd, 2022) Ayna, Tuncer; Dilibal, SavasWater jet ejectors are the silent pumping fluid devices which doesn't have any rotating parts in functional industrial applications. The dimensionless geometrical parameters effects ejector suction capacity. In this study, it is found that optimum design intervals have been determined by using the Response Surface Method (RSM). Design ranges determined in the dimensionless study have been used in the improvement of the suction capacity of an existing ejector. The suction capacity of the existing ejector is investigated via numerical and experimental analysis. Two new water jet ejector designs (D1 and D2) are built to improve the suction capacity of the initial water jet ejector (D0). The generated design parameters have been analyzed by using SolidWorks flow analysis and optimization software. The suction capacity of the ejector has been determined through the iterative numerical analysis for the selected geometrical parameters under the applied design conditions. The effect of design parameters on the suction capacity of the water jet ejectors is unveiled through numerical and experimental analysis. The established designs were produced as two novel bronze water jet ejectors. The suction capacities of the produced bronze water jet ejectors have been investigated experimentally. The numerical results have been validated using the experimental results. It is achieved that the suction capacity of the manufactured water jet ejector with the improved design (D2) is suddenly increased from 52.05 m3/h to 103.4 m3/h.Öğe Experimental Investigation of Wire Arc Additively Manufactured Inconel 625 Superalloy(Springer India, 2023) Gurol, Ugur; Tumer, Mustafa; Dilibal, SavasThe aim of the present study was to reveal how the microstructure and mechanical properties of Inconel 625 superalloy produced via wire arc additive manufacturing (WAAM) changed in relation to deposition direction. Results showed that the microstructure mainly consists of columnar dendrites including some intermetallic and carbides constituents, which are Laves and NbC phases. The hardness values showed heterogeneous distribution from bottom to top and mainly change between 275 +/- 15 to 298 +/- 16 HV5 except for the initial area reaching 318 +/- 14 HV5. The tensile test results revealed that the stress-strain responses of the samples change depending on the extracted direction. The lowest elongation was obtained at the transverse top and bottom regions with 33.5 +/- 1.5% and 35 +/- 6% while the highest elongation was obtained at the angular top and bottom with 48.5 +/- 6.7% and 55.5 +/- 2%. The results confirmed the more pronounced difference with sample direction, indicating anisotropy in ductility.Öğe Experimental Investigation on the EBM-Based Additively Manufactured Prismatic Nickel-Titanium SMA Components(Pleiades Publishing Inc, 2021) Altug-Peduk, Gozde S.; Dilibal, Savas; Harrysson, Ola; Ozbek, SunullahAdditive manufacturing (AM) of the nickel-titanium (NiTi) shape memory alloys (SMA) have provided novel component solutions with a variety of design configurations in the industry. Electron beam melting (EBM) is a trending metal additive manufacturing process for industrial applications in the field of biomedical and aerospace engineering. In this study, experimental investigations were conducted to reveal the effect of processing conditions on the microstructure and hardness properties of EBM-fabricated nickel-titanium components. Furthermore, detailed microstructural characterizations were performed with a scanning electron microscope, EDS, and XRD for unveiling of the microscopic structure and phase analysis during the layer by layer solidification. The experimental results were systematically evaluated for the powder and the bulk prismatic components, respectively.Öğe Fabrication and Characterization of Wire Arc Additively Manufactured Ferritic-Austenitic Bimetallic Structure(Korean Inst Metals Materials, 2023) Gurol, Ugur; Turgut, Batuhan; Kumek, Hulya; Dilibal, Savas; Kocak, MustafaBimetallic parts are used in many industrial fields, such as pressure vessels, shipbuilding, aerospace, and automotive industries. Conventional bimetallic part production involves a combination of two different metals that are joined using welding and brazing operations. Additive manufacturing technologies offer a cost-effective and innovative manufacturing alternative for complex 3D-shaped parts that can have multi-material designs for better structural performance. However, the structural performance of bimetallic components is primarily influenced by the combination of the employed materials, the interface's morphology, and interface bonding strength. This work investigated the microstructure and mechanical behavior of a bimetallic thick-walled structure as WAAM Wall fabricated by depositing low-alloyed metal-cored wire on the top of 316L stainless steel by robotic wire arc additive manufacturing (WAAM) process. The results showed that both low-carbon steel and austenitic stainless steel SS316L wires are suitable for manufacturing defect-free bimetallic WAAM components, which may widen the design flexibility to manufacture bi-metallic and or functionally graded WAAM components. However, detailed microstructural characterization indicated that martensitic microstructure containing chrome carbides was developed at the bimetallic interface due to an increase in Ni and Cr contents, resulting in a sudden increase of 95% in hardness and a sharp decrease of 70% in fracture toughness at the interface region compared to the SS 316L side. This high-hardness region also resulted in an increase of about 113% and 86% for yield and tensile strengths and a sharp reduction of 69% for elongation values in horizontal interface specimens compared to vertical interface specimens.Öğe Finger-Like Manipulator Driven by Antagonistic Nickel-Titanium Shape Memory Alloy Actuators(IEEE, 2015) Dilibal, Savas; Engeberg, Erik D.Shape memory alloy (SMA) actuators generally have a fast response time when heated. However, the return stroke during cooling can be slow and has been a hindrance to the application of SMA actuators in different areas such as robotic hands. Thus, a novel finger-like antagonistic SMA actuator design is presented in this paper. By using different thermal shape setting processes, one SMA actuator was designed to take a curved shape when heated. This actuator was antagonistically coupled to a different actuator that took a straight shape when heated. Thus, alternately heating each actuator caused the finger- like manipulator to flex and extend rapidly. A comparison study was performed between the novel antagonistic design and a single actuator which showed that the both designs applied approximately the same force with the same velocity when flexing. However, the antagonistic design was able to extend, or open, more rapidly with statistical significance. This was demonstrated for 1.5mm, 1.9mm, and 3.0mm SMA actuator diameters.Öğe Hybrid Battery Thermal Management System with NiTi SMA and Phase Change Material (PCM) for Li-ion Batteries(Mdpi, 2022) Joula, Mohammad; Dilibal, Savas; Mafratoglu, Gonca; Danquah, Josiah Owusu; Alipour, MohammadPoor heat dissipation and thermal runaway are most common in batteries subjected to fast charge or discharge and forced to work in hot or subzero ambient temperatures. For the safe operation of lithium-ion batteries throughout their lifecycle, a reliable battery thermal management system (BTMS) is required. A novel hybrid BTMS with a nickel-titanium (NiTi) shape memory alloy (SMA) actuated smart wire and phase change material (PCM) with expanded graphite (EG) is proposed in this study. A lumped electrochemical-thermal battery model is developed to analyze the efficiency of the proposed hybrid BTMS. The multiphysics BTMS is investigated by discharging at various electrical currents in both off-modes (inactivated SMA) and on-modes (activated SMA). Under on-mode BTMS operation, temperature elevation is reduced by 4.63 degrees C and 6.102 degrees C during 3 C and 5 C discharge, respectively. The proposed hybrid BTMS can be considered a competitive alternative for use in electrical vehicles due to its smart, compact, safe, and efficient performance in both cold and hot environments.Öğe Joint Control Implementation of 4-DOF Robotic Arm Using Robot Operating System(IEEE, 2022) Ben Hazem, Zied; Ince, Resul; Dilibal, SavasThe paper describes the joint position control implementation for 4 degrees of freedom (4-DOFs) robot manipulator with a robot operating system (ROS) that may be used for robotics courses. ROS contains various plugins and software packages for robots' data analysis used in robotic engineering education. To accomplish the position control of joints using the ROS, the connection between the Arduino controller board and ROS was created. Moreover, using the Arduino controller board, all motors of the 4-DOFs arm robot are controlled using a PID controller. The forward and inverse kinematic models for the 4-DOFs robot manipulator are also developed based on the Denavit-Hartenberg (DH) method. The obtained DH parameters were used in the 3D kinematic model trajectory provided by the RoboAnalyzer software to determine the position, velocity, and acceleration plots for each joint. The direct and inverse kinematic models are used in the implementation of the position controller. The results further indicate that the proposed position control using the PID controller in ROS returns accurate tracking results in terms of minimum root mean squared errors (RMSEs) that can be used in the control of any industrial robot.Öğe Smart Adaptronic Thermal Management System Designs for The Li -ion Battery Packs(IEEE, 2021) Joula, Mohammad; Dilibal, Savas; Owusu-Danquah, JosiahLi-ion battery packs are used in varied industrial fields, such as automotive, drone, and e-bike industries. Low temperature insulation and high temperature heat conduction are required for an ideal thermal management of battery pack. In this study, an autonomous system design is developed for a smart adaptronic Battery Thermal Management System (BTMS). We proposed two different nickel-titanium (NiTi) shape memory alloy (SMA)-actuated smart adaptronic BTMSs. The actuation strain of the system is examined using a computational NiTi shape memory alloy model for material selection. The model results showed that an actuation strain of 3.8 % can be obtained for the operating temperatures range between 15 C and 80 C. The model results is used to unveil the required properties of NiTi SMA wire. The proposed adaptronic BTMS design solutions can create competitive advantages with their compact, low-cost, and lightweight structures in industry.Öğe STABILIZED ACTUATION OF A NOVEL NiTi SHAPE-MEMORY-ALLOY-ACTUATED FLEXIBLE STRUCTURE UNDER THERMAL LOADING(Inst Za Kovinske Materiale I In Tehnologie, 2018) Dilibal, SavasShape-memory-alloy (SMA) actuated flexible structures are used in a variety of configurations in many aerospace, robotics and underwater applications. In this study, a pair of nickel-titanium (NiTi) shape-memory-alloy plates is embedded in a flexible structure. An antagonistic design with a plate geometry is selected for the NiTi SMA to achieve bidirectional flexibility. A three-point-bending test is conducted to reveal the bending strength of the NiTi plates in the martensite and austenite phases. The antagonistic NiTi SMA plates are geometrically adapted and embedded into the flexible structure, which is fabricated through additive manufacturing using thermoplastic-polyurethane (TPU) flexible filament. The stabilized actuation stages of the antagonistic NiTi SMA plates embedded in the flexible structure are examined through observation of an extended number of thermal cycles. A comparison is made by applying two different electrical-current values with a regulated high-current DC power supply. A cycling profile with a maximum, bidirectional, stabilized actuation stroke of 52 mm is obtained through 100 heating/cooling cycles for the NiTi SMA-plate-actuated flexible structure. The effects of the high and low heating/cooling cyclic periods on the stabilized actuation stroke are also investigated.Öğe The Effect of Heat Treatment on the Superelastic Behaviour of Nickel-Titanium Shape Memory Alloys(Gazi Univ, 2017) Dilibal, SavasShape memory alloys (SMAs) which are the intermetallic materials, exhibit shape memory effect and superelastic behaviour in the macro-structure throught the reversible thermoelastic phase transformation between austenite and martensite phases in the microstructure. Nickel-titanium (NiTi) SMAs became widespread in several applications, especially in the biomedical field due to their superelastic behavior. In this study, the effect of heat treatment on the SMA's phase transformation temperature is experimentally investigated using the Ti-50.8 at.% Ni samples. The experimental results which are received from the differential scanning calorimety (DSC) analyses and tensile test are compared. The effect of solutionizing and aging treatments on the superelastic behaviour is investigated.
