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An ANFIS model for predicting workpiece deformation during the milling of thin-walled composite components
(Sage Publications Ltd, 2026) Ozdemir, Burak; Emir, Ender; Bahce, Erkan; Yardimeden, Ahmet; Kilickap, Erol
The milling of thin-walled structural components is a meticulous procedure, particularly for workpieces with diminished mechanical qualities. Such workpieces are subject to greater deformation due to the cutting force. These deformations have a negative effect on the machining accuracy of the machined parts. Therefore, it is important to focus on the causes and effects of workpiece deformation in order to understand the surface machining quality of the workpiece. The aim of this study is to calculate the deflection of the workpiece during milling of thin-walled components made of glass fiber reinforced polymer composite (GFRP), carbon fiber reinforced polymer composite (CFRP) and basalt fiber reinforced polymer composite (BFRP). The tests were carried out at three different feed rates (0.1-0.2-0.3 mm/rev) and three different speeds (2000-3000-4000 r/min). A high-speed camera was used to detect the deflection of the thin-walled workpiece during milling. The effect of machining parameters on the variation of cutting force and deflection was statistically evaluated by analysis of variance. In order to better understand the behaviour of the parameters in the process, a predictive model was created using the artificial intelligence method Adaptive Network Based Fuzzy Inference System (ANFIS). The model is able to predict the cutting force with an accuracy of 65.7% and the deformation with an accuracy of 98.9%.
Analysis of Drilling Behaviour in Jute Fibres Reinforced Natural Composites
(Taylor & Francis Inc, 2023) Ozdemir, Burak; Yardimeden, Ahmet; Bahce, Erkan; Kilickap, Erol; Emir, Ender
In the study, Natural jute composite materials, which have environmental advantages due to their easily degradable nature were drilled with different processing parameters and the effects of thrust force, vibration and temperature changes on hole quality were investigated. The effect of feed and spindle speed was statistically analyzed using ANOVA method. The thrust force, vibration and temperature factors that occur depending on the drilling parameters vary and affect the roughness and delamination values. The effect of feed and speed on thrust force was calculated as 97.87% and the feed effect (90.85%) is far greater than the speed (9.15%). The effect of drilling parameters on vibration is statistically insignificant due to the different spread behavior in the layers of the composite material (R2 = 0.2329). However, feed effect on vibration (94.6%) is greater than the speed effect (6.06%). The temperature is affected by 96.93% of the drilling parameters and the speed is 84.16% and the feed is 15.83%. The roughness effect depending on the drilling parameters is measured as 84.91%. The effect of speed on roughness (90.26%) is greater than the feed (9.73%). It has been determined that this situation is mostly related to vibration and temperature.
ANALYZING THE EFFECTS OF DIFFERENT TOOL PATHS ON FORM ERRORS IN THE MILLING OF FREEFORM SURFACES
(Yildiz Technical Univ, 2020) Bahce, Erkan; Ozdemir, Burak
Machining of free-form surfaces is an important place in terms of design and performance in transportation, electronics and aeronautical industry. Problems such as form error and surface roughness were frequently encountered in the manufacture of these surfaces. For the solution of the problems, reprocessing is done, which causes time and resource loss. To eliminate these losses, the parts must be produced in the desired quality at one time. In order to find out the causes of form errors and to remove the adverse effects, the distribution on the surface must be determined correctly. Form errors should be examined in a way to cover the point, region and the whole part. In this study, a surface created with B-Spline curve has been processed with different tool paths. Surfaces were scanned in 3D and form errors were determined. Point, regional and whole parts are examined and the tool path that creates minimum form error is determined.
Bio-Inspired Graded and Uniform Cylindrical Lattices Fabricated by Material Extrusion 3D Printing: An Experimental and Numerical Investigation
(Wiley, 2025) Oymak, Mehmet Akif; Bahce, Erkan; Singh, Gurminder
The main requirements of the biomedical and aerospace industries are new and innovative lightweight materials. Bio-inspired structures, which are inspired by various biological designs, have demonstrated notable advancements over traditional lightweight structures. In this study, bioinspired uniform and graded cylindrical triply periodic minimal surface (TPMS) and strut-based lattice structures were studied for their mechanical qualities and energy absorption capacities fabricated by material extrusion 3D printing using PLA material. It was found that the cylindrical TPMS diamond lattice achieved maximum stress of 78.5 MPa and absorbed 19.14 MJ/m3 of energy, outperforming strut-based designs with a 48% higher energy absorption than cylindrical BCC lattice structure. Graded designs further improve energy absorption through a better stress distribution. The findings validated the Gibson-Ashby model, highlighting the enhanced load distribution and stress transfer in the strut-based and TPMS diamond structures. The finite element (FE) model results closely matched the experimental data, confirming its predictive reliability with a maximum error of energy absorption of 7.7%, elastic modulus of 6.9%, and plateau stress of 4.7%. These insights underscore the superior energy absorption and mechanical stability of cylindrical TPMS diamond lattices, indicating their potential for satisfying stringent industrial and technical performance requirements. The novelty of these designs lies in their bioinspired structures and significant enhancements in mechanical performance and energy absorption. Future research should build on these results to design efficient materials tailored to specific needs using FE models to optimize development processes before experimental testing.
Burr Measurement Method Based on Burr Surface Area
(Korean Soc Precision Eng, 2021) Bahce, Erkan; Ozdemir, Burak
One of the major issues of drilling operations pertains to the formation of burrs, which greatly influences the accuracy of the manufactured parts, and, thus, the capability to meet the desired performance of the part. To remove or prevent these burrs, their geometry must be measured accurately, even though they are sharp and irregular in shape. The accurate measurement of the geometry of a burr will lead to the development of a proper deburring method. In this work, the authors describe a simple and convenient new measurement technique for drilling burr profiles and a developed drilling burr measurement system based on surface area. The new method presented in this research aims at providing a comparative evaluation of the height, arc length and area of the burr, as well as its geometrical characteristics. When the average height and arc length measurement methods are compared with the area measurement method, large deviations in burr height are detected. In particular, these deviations increase more in non-uniform burrs. In the measurement of burr size, the new developed method is based on area measurement and is carried out using a computer. Therefore, there is no deviation between the measurements. In contrast, the average deviation ranges for the height and arc length measurement methods are found to be 9.94-48.14% and 6.07-18.82%, respectively.
CASE STUDY OF A DISTAL FEMUR TI6Al4V LOCKED COMPRESSION PLATE FAILURE SURFACE INVESTIGATION AND FINITE ELEMENT ANALYSIS
(World Scientific Publ Co Pte Ltd, 2024) Can, Murat; Oymak, Mehmet Akif; Koluacik, Serdar; Bahce, Erkan; Uzunyol, Omer Faruk
In this study, the failure of locking compression plates (LCP) used in the treatment of bone fractures resulting from falls in orthopedic patients at Malatya Training and Research Hospital was investigated. The researchers examined the fracture surface of the failed Ti6Al4V LCP using scanning electron microscopy (SEM) and energy dispersive X-ray spectroscopy (EDX) images. The fracture pattern of the plate caused by the fall was replicated in a computer-aided design (CAD) model, obtained through three-dimensional (3D) scanning. Additionally, a CAD model of the femur bone was created using magnetic resonance (MR) images. The assembled images of the replicated fracture and the femur bone were used to simulate the application of locked and unlocked compression screws. Considering the weight-bearing load on a human femur, a linear load of 1200 N and 300 N iliopsoas 300 N abductor 600 N hip contact and 70 N tensor fascia latea walking loads had been applied using finite element analysis (FEA). The researchers analyzed the total deformations, von Mises stress, and principal stresses of the plate. When FEA was conducted with walking and body forces applied, it was observed that the walking forces resulted in a 20% higher von Mises stress and a 22.5% greater total deformation 15% low cycle fatigue compared to the body force. During the analysis with walking forces applied, it was noticed that the maximum von Mises stresses on the LCP and the point where fatigue initiation began coincided with the fracture site of the LCP in the patient's body. However, this observation was in contrast to the analysis with body loads applied.
Compressive behavior of functional graded hybrid lattice structure
(Springer London Ltd, 2025) Emir, Ender; Bahce, Erkan
Today, lattice structures are preferred in various fields, including biomedical, aviation, and the defense industry, due to their exceptional mechanical properties, low density, high specific strength, high specific stiffness, good energy absorption ability, and excellent thermal and acoustic insulation. This study focused on investigating the mechanical performance of functionally graded hybrid (FGH) lattice structures. Three types of lattice structures were designed: triple periodic minimal surface (TPMS)-based primitive-gyroid (P-G); body-centered cubic-gyroid (BCC-G); and primitive-body centered cubic (P-BCC) hybrid lattice structures. In addition, each hybrid lattice structure was formed both in the large porosity size and in the production direction from the large pore size to the small pore size. These hybrid lattice structures were then fabricated using selective laser melting (SLM). In the results of compression tests on FGH lattice structures with large pore sizes, the P-BCC structure exhibited the highest elastic modulus among the test specimens, measuring 1573.17 MPa. The highest yield strength was found to be 128.46 MPa in the BCC-G hybrid lattice structure. Furthermore, when evaluating the energy absorption capabilities of hybrid lattice structures with a large pore size, the BCC-G structure demonstrated the highest resilience and toughness among the test samples. On the other hand, an increase in elastic modulus, yield strength, and energy absorption values was observed with the decrease in pore size. However, it was observed that the change in pore size due to defects in the production of lattice structures is another effective parameter on mechanical properties. This study suggests that desired mechanical properties can be achieved through the functional grading of pore size and the creation of hybrid structures utilizing different lattice designs.
Detection of periapical lesions in teeth with fixed prostheses using segmentation models and analyzing crown–lesion relationships
(Elsevier Inc., 2025) Gul, Buse Cebi; Cebi, Can; Malkoc, Ersel; Altinsoy, Burcin; Bahce, Erkan; Karabas, Ayse
Statement of problem: Periapical lesions in teeth with fixed prostheses often remain undiagnosed in routine panoramic radiographic evaluations, leading to delayed treatment and potential tooth loss. The complex anatomy of prosthetic restorations can mask early periapical pathology, and manual detection is time-consuming and subject to interobserver variability. A standardized automated system is not currently available for the simultaneous detection of periapical lesions and the analysis of their relationship with fixed prostheses in panoramic radiographs. Purpose: The purpose of this study was to evaluate the diagnostic accuracy of artificial intelligence models based on the YOLO11 architecture for detecting periapical lesions in teeth with fixed prostheses on panoramic radiographs and to analyze crown–lesion relationships using automated algorithms. Material and methods: A total of 1686 annotations (1033 crowns, 653 periapical lesions) were manually labeled on 404 retrospectively selected panoramic radiographs obtained from patients at Inonu University Faculty of Dentistry between March 2024 and May 2025. Manual labeling was performed independently by 2 experienced observers using the Roboflow platform. The dataset was divided into 77% training (312 images), 13% validation (52 images), and 10% testing (40 images). Five YOLO11 segmentation variants were trained for 150 epochs. Model performance was evaluated using precision, recall, mAP50, and mAP50–95 metrics. Statistical analyses were performed using Python 3.9 with scikit-learn and scipy libraries (α=.05). Receiver operating characteristic (ROC) curves and area under the curve (AUC) values were calculated for diagnostic performance assessment. Results: The YOLO11l-seg model achieved the highest performance with mAP50 of 0.885, recall of 0.853, and precision of 0.847. While all models demonstrated high success in crown detection (mAP50: 0.975 to 0.980), YOLO11l-seg yielded the best results for periapical lesion detection (mAP50: 0.794). Crown–lesion relationship analysis revealed that 84.62% of lesions were associated with crowns, with mandibular crowns showing a 2.7 times higher lesion prevalence than maxillary crowns (52.24% against 19.05%, P<.001). Conclusions: YOLO11-based artificial intelligence models demonstrated high accuracy for detecting periapical lesions in teeth with fixed prostheses. The developed Python algorithm successfully analyzed crown–lesion relationships, providing quantitative data for clinical assessment. © 2025 Editorial Council for The Journal of Prosthetic Dentistry
Determination of tool deflection in drilling by image processing
(Inst Engineering Technology-Iet, 2019) Bahce, Erkan; Ozdemir, Burak
It is known that parameters such as the feed rate and the spindle speed affect the hole quality during the drilling of aluminium and its alloys. In particular, deflection occurs as a result of the increase or decrease of the reverse forces acting on the tool as a result of changing the parameter values. The tool deflection causes deviations in the hole geometry. This requires the initial detection of the deflection on the tool and then the most appropriate updating of the drilling parameters. At the present time, force-based estimation and inductive or laser sensor detection methods are used for the detection of tool deflection. These methods are useless because they require expensive measurement systems and continuous fine-tuning. This study aimed to calculate the tool deflection that occurs during the drilling of AL 7075 material using an image processing technique. In the experiments using different drilling parameters, the tool deflection was calculated and the effects of the parameters on tool deflection were investigated. As a result, it is shown that the tool deflection can be detected quickly and simply by image processing. In addition, the effects of the processing parameters on the tool deflection are discussed.
Effect of Octet-Truss Lattice Transition Geometries on Mechanical Properties
(Springer, 2021) Emir, Ender; Bahce, Erkan; Uysal, Alper
Additive manufacturing (AM) enables the production of lattice structures with unique properties using different production techniques. In this way, it is possible to obtain the desired mechanical properties by using different production parameters and lattice geometries. In this study, the load behaviors of the octet-truss lattice structure produced by fused deposition modeling (FDM) method with different transition geometries were investigated. Compression tests were carried out on lattice structures and also finite element method (FEM) was performed to determine the stress distributions and deformations. According to the results, it was observed that the transition geometry is an important parameter on the deformation patterns and stress distributions. In the lattice structure without transition geometry, plastic deformation occurred at low-stress values while the transition geometries exhibited plastic deformation at high-stress values. In addition, the effects of the transition geometries on the deformation types were observed. The deformation area on the samples having straight and inclined-transition geometries affected less area than the sample without transition geometry. It was found out that the stretch-dominated deformation type, which significantly affects the strength of the lattice structures subjected to load, was formed in all lattice structures.
The effects of HAp coating layer on mechanical and optical properties at bonding interface of high-performance polymers
(Elsevier, 2023) Demirci, Fatih; Bahce, Erkan
Purpose: The effect of hydroxyapatite (HAp) coating layer on mechanical and optical properties at bonding interface of high-performance polymers (HPPs) used in computer-aided design (CAD)/computer-aided manufacture (CAM) technology was investigated in this in vitro study. Materials and methods: Two hundred-twenty specimens were divided into two material groups (n = 110): polyetheretherketone (PEEK, KERA (R) starPEEK) and polyetherketoneketone (PEKK, Pekkton (R) ivory). For mechanical testing, each group was divided into five surface pretreatment subgroups and a control group (n = 10): HAp coating (1%,3%, 5%, and 10% concentrations) and sandblasting with 110-mu m Al2O3 particles. For optical testing, each group was divided into five subgroups (n = 10): HAp coating (1%, 3%, 5%, and 10% concentrations) and control. The effects of the HAp coating on the optical changes and shear bond strength (SBS) of the specimens were investigated. Data was statistically analyzed by one-way ANOVA and Tukey's post-hoc test. Failure modes and surface properties of the specimens were examined by scanning electron microscopy (SEM) and coupled electron dispersive spectroscopy (EDS). Results: Average translucency and color change values increased with increasing HAp coating concentration in HPPs. As a result of the data, statistically significant differences were observed in terms of the effect of the HAp coating on SBS of HPPs (p < 0.05). Failure modes were examined, and mixed failure mode was observed. Conclusion: HAp coating can contribute to the improvement of both the optical properties and bond strength of the HPPs to resin composite. Clinical significance: Adhesion and color problems of high performance polymers are still under discussion. In order to solve these problems, generally focused on surface modifications of these polymers, but the effect of the HAp coating has not been investigated.
Electrochemical Corrosion and Metal Ion Release Protective Efficiency of the Multilayer TaN Coatings on CoCrMo Biomedical Alloy
(Kaunas Univ Tech, 2021) Aslan, Ali Kemal; Bahce, Erkan; Guler, Mehmet Sami
CoCrMo alloy is widely used in artificial orthopedic joint applications due to its high mechanical properties. But, high levels of the metal ion release from alloy surfaces cause variable toxic and allergic effects on the patient in vivo use. This case restricts the lifetime of the implant and results in the failure of the artificial joint. In order to enhance the corrosion resistance and to decrease the metal ion release, alloy surface was multilayer-coated by closed field unbalanced magnetron system. The protective efficiency of the coatings was determined by potentiodynamic polarization tests and static immersion tests were performed for 45, 60 and 90 days in the simulated body fluid in order to understand the effect of the coatings on the metal ion release. The metal ion concentrations in the simulated body fluids were determined by using inductively coupled plasma mass spectrometry device. The electrochemical corrosion results showed that the multilayer coatings provided 93 % protective efficiency in terms of corrosion resistance. Multilayer coatings decreased the metal ions release levels significantly, especially Co leaking was decreased approximately 52 times compared to uncoated samples.
Evaluating the performance of AI chatbots in responding to dental implant FAQs: A comparative study
(Bmc, 2025) Tuzlali, Mesut; Baki, Nagehan; Aral, Kubra; Aral, Cuneyt Asim; Bahce, Erkan
Background This study aims to evaluate and compare the performance of five publicly accessible large-language-model (LLM) based chatbots-ChatGPT-o1, Deepseek-R1, Google-Gemini-Advanced, Claude-3.5-Sonnet, and Perplexity-Pro-in providing responses to frequently asked questions (FAQs) about dental implant treatment. The primary goal was to assess the accuracy, completeness, clarity, relevance, and consistency of chatbot-generated answers. Methods A total of 45 FAQs commonly encountered in clinical practice and online patient forums regarding dental implants were selected and categorized into nine thematic domains. Each question was submitted to the chatbots individually using a standardized protocol. Responses were independently assessed by a panel of four dental experts and one layperson using a 5-point Likert-scale. Python with Google-Colab was used for statistical analysis. Results ChatGPT-o1 achieved the highest overall performance, particularly in relevance (M = 4.99), consistency (M = 4.97), and accuracy (M = 4.96). Deepseek-R1 followed closely, with strong scores in completeness and relevance. Claude-3.5-Sonnet ranked moderately, while Gemini-Advanced and Perplexity-Pro showed lower performance in completeness and clarity. Significant differences were observed among chatbots across all criteria (p < 0.001). Inter-rater reliability was high (alpha = 0.87), confirming consistency among evaluators. Conclusions AI-driven chatbots demonstrated strong potential in delivering accurate and patient-friendly information about dental implant treatment. However, performance varied considerably across platforms, with ChatGPT-o1 and Deepseek-R1 showing the highest reliability. These findings highlight the emerging role of AI chatbots as supplementary tools in dental education and patient communication, while also underscoring the need for continued validation and ethical oversight in clinical applications.
Evaluation of the accuracy of dental casts manufactured with 3D printing technique in the All-on-4 treatment concept
(Korean Acad Prosthodontics, 2022) Tas, Hilin; Demirci, Fatih; Tuzlali, Mesut; Bahce, Erkan; Avcu, Guler Yildirim
PURPOSE. The aim of this study is to compare the casts obtained by using conventional techniques and liquid crystal display (LCD) three-dimensional (3D) print techniques in the All-on-4 treatment concept of the edentulous mandibular jaw. MATERIALS AND METHODS. In this study, a completely edentulous mandibular acrylic cast (typodont) with bone-level implants placed with the All -on-4 technique served as a reference cast. In this typodont, impressions were taken with the conventional technique and dental stone casts were obtained. In addition, after scanning the acrylic cast in a dental laboratory scanner and obtaining the Standard Tessellation Language (STL) data, 3D printed casts were manufactured with a 3D printing device based on the design. The stone and 3D printed casts were scanned in the laboratory scanner and STL data were obtained, and then the interimplant distances were measured using Geomagic Control X v2020 (3D Systems, Rock Hill, SC, USA) analysis software (n = 60). The obtained data were statistically evaluated with one-way analysis of variance (ANOVA) and Tukey's pairwise comparison tests. RESULTS. As a result of the one-way ANOVA test, it was determined that the stone casts, 3D printed casts, and reference cast values in all distance intervals conformed to the normal distribution and these values had a significant difference among them in all distance intervals. In Tukey pairwise comparison test, significant differences were found between casts at all distance intervals. In all analyses, the level of significance was determined as .05. CONCLUSION. 3D printed casts obtained with a 3D LCD printing device can be an alternative to stone casts when implants are placed in edentulous jaws. [J Adv Prosthodont 2022;14:379-87]
Examining the impact of fiber orientation angle and drilling parameters on the quality of holes in GFRP pipes
(Sage Publications Ltd, 2025) Ozdemir, Burak; Emir, Ender; Bahce, Erkan; Yardimeden, Ahmet; Kilickap, Erol
This study examined the impact of altering the fiber orientation angle on delamination and surface quality in glass fiber reinforced polymer (GFRP) pipes. GFRP pipes are manufactured at three distinct orientation angles: 30 degrees, 60 degrees, and 90 degrees. Experiments were conducted at four distinct feed rates (0.05, 0.1, 0.2, 0.3 mm/rev) at three varying speeds (2000, 4000, 6000 rpm). The impact of the fiber orientation angle on thrust force, entry and exit delamination, and surface roughness of the holes was examined. The orientation angle significantly affected other parameters (p < 0.05). An orientation angle of 90 degrees generated increased thrust force while reducing roughness and delamination in comparison to other orientation angles. At a 90 degrees orientation angle relative to 30 degrees and 60 degrees, an approximate increase in thrust force of 4.8%-4.1%, a decrease in surface roughness of 25%-21%, and a decrease in delamination of 23%-7% was observed.
Experimental and numerical study on micro-milling of CoCrW alloy produced by selective laser melting and casting
(Sage Publications Ltd, 2024) Oymak, Mehmet Akif; Bahce, Erkan; Gezer, Ibrahim
CoCrW can be produced using Additive Manufacturing (AM), while casting methods are commonly used for applications such as dental prostheses. However, rapid heating and cooling during AM production can lead to internal defects, micro-cracks, and shrinkage. Micro-milling can help enhance the material's structure and impart micro-scale properties. This study aimed to investigate the micro-milling properties of CoCrW products manufactured using AM and compare them with materials produced by casting. Numerical models and experimental studies were conducted to examine the differences. Results showed that CoCr alloys produced with AM exhibited 25%-30% lower burr formations, while CoCrW produced by casting had 2%-5% lower surface roughness. Micro-milling experiments demonstrated that a feed rate of 2.5 mu m/tooth resulted in 35%-40% more burr formation and surface roughness compared to a feed rate of 5 mu m/tooth in both SLM and casting methods, attributed to the cutting edge radius. The cutting temperature and top burr height were analyzed using finite element simulations and experimental methods. It was observed that the maximum temperature in CoCrW produced by casting was 6%-15% higher than that in the SLM method. The finite element analyses and experiments revealed a difference of 4%-7% in maximum temperatures and top burr height.
Experimental investigation and FEM analysis of chip morphology in the turning of ASTM F-75 CoCrMo alloy
(Yildiz Technical Univ, 2024) Emir, Ender; Ozdemir, Burak; Bahce, Erkan
During the machining process, problems such as tool wear, high temperature, force distribution, and surface quality deterioration must be fully understood. Control of these problems with experimental studies and numerical analyses is important in ensuring dimensional accuracy and surface integrity of the cutting tool, workpiece, and also the finished product. The aim of this study is to investigate the effects of machining parameters on chip morphology, residual stresses and tool wear in turning operations of ASTM-F75 CoCrMo alloy experimentally and by finite element method (FEM) simulation. The study was carried out at three different feed rates (0.1, 0.2, 0.3 mm/rev) and at a constant cutting speed of 80 m/min both experimentally on a CNC turning machine and with FEM simulation. From the obtained results, the formation of cracks and adhesions on the surfaces of the chip were observed due to the increase of the feed rate. According to the orthogonal cutting model, chip height ratio (Gs) and tooth pitch (Pc) values of saw-tooth chips supported each other with measurements taken from both FEM images and experimental images. With the increase of the forward speed, the Gs ratio decreased, while the Pc increased. In addition, microscopic images obtained from the cutting tool also showed that the rate of crater wear gradually increased with increasing feed rate. As a result, it is seen that machining parameters have a significant effect on cutting tool and chip morphology in CoCrMo ASTM-F75 alloy turning.
Experimental Investigation of Delamination Formed by Bone Drilling
(Univ Osijek, Tech Fac, 2020) Koluacik, Serdar; Can, Murat; Bahce, Erkan
Bone drilling is a common method for fixing implants used in bone fractures. Because of the fibre-reinforced composite structure of bone, parameters such as feed rate, spindle speed and drill type affect the hole surface quality. After drilling, the quality of the bore surface, burr formation and delamination at the hole entrance and exit affect the ability of the screw to cause implant failure and fusion problems of the fracture. For this reason, it is very important to conduct drilling with optimum speed and feedrate values. In this study, the effects of processing parameters on hole surface quality and delamination were studied experimentally. In the experiment, bovine bone, which has similar structural properties to human bone, was used. The hole surface quality and delamination formed at the exit of the hole were examined for three different feed rates and spindle speeds. As a result of the experiments, it was seen that the feed rate had more effect on both delamination and hole surface quality than the spindle speed. It was also determined that the cortical part of the bone and the cancellous part of the bone affected the production of heat and drill wear differently.
Fabrication and machining of aluminum-reinforced graphite metal matrix composites
(Taylor & Francis Inc, 2025) Olmez, Cebrail; Bahce, Erkan; Koytepe, Suleyman; Cakir, Mustafa Cemal; Kurt, Oguz
Shaping of aluminum alloys by chip removal has increased significantly in the industry. Accordingly, issues aiming to reduce friction between the tool and the workpiece and to increase tool life have gained importance. As a result, despite the common use of coolant, minimal lubrication, and cryogenic cooling, it is expected that studies for dry processing will increase day by day due to environmental damage and high costs of the coolant. In this study, the effects of reinforcing solid lubricants in aluminum alloys onto the tool wear and surface integrity during the cylindrical turning of composites were investigated. As a result of the study, it was measured that the reinforcement material graphite reduces the temperatures occurring in the cutting zone in the turning process by an average of 22.5%. Accordingly, improvements in surface roughness values were achieved, cutting tool wear was reduced and tool life was increased by approximately 27%. Within the scope of this study, it can be stated that sustainable production is achieved without using cutting fluids that are costly, harmful to the environment and human health.
Finite element analysis of lattice designed lumbar interbody cage based on the additive manufacturing
(Sage Publications Ltd, 2023) Bozyigit, Bulent; Oymak, Mehmet Akif; Bahce, Erkan; Uzunyol, Omer Faruk
Additive manufacturing (AM) methods, which facilitate the production of complex structures with different geometries, have been used in producing interbody cages in recent years. In this study, the effects of Ti6Al4V alloy interbody lattice designed fusion cages between the third and fourth lumbar vertebrae where degenerative disc diseases occur were investigated using the finite element method. Face centered cubic (FCC), body centered cubic (BCC), and diamond structures were selected as the lattice structure suitable for the interbody cage. A kidney shaped interbody lumbar cage was designed. The designated lattice structures were selected by adjusting the cell sizes suitable for the designed geometry, and the mesh configuration was made by the lumbar lattice structure. 400N Axial force and 7.5 N.m moments were applied to the spine according to lateral bending, flexion, and torsion. 400N axial force and 7.5 N.m flexion moment is shown high strain and total deformation then lateral bending and torsion on BCC FCC and diamond lattice structured interbody cages. In addition, the effects of lattice structures under high compression forces were investigated by applying 1000N force to the lattice structures. When von Mises stresses were examined, lower von Mises stress and strains were observed in the BCC structure. However, a lower total deformation was observed in the FCC. Due to the design of the BCC and the diamond structure, it is assumed that bone implant adhesion will increase. In the finite element analysis (FEA), the best results were shown in BCC structures.

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