Micro-turning is a micro-mechanical cutting method used to produce small diameter cylindrical parts. Since the diameter of the part is usually small, it may be a little difficult to improve the surface quality by a second operation, such as grinding. Therefore, it is important to obtain the good surface finish in micro turning process using the ideal cutting parameters. Here, the multi-objective optimization of micro-turning process parameters such as cutting speed, feed rate and depth of cut were performed by response surface method (RSM). Two important machining indices, such as surface roughness and material removal rate, were simultaneously optimized in the micro-turning of a Ti6Al4V alloy. Further, the scanning electron microscope (SEM) analysis was done on the cutting tools. The overall results depict that the feed rate is the prominent factor that significantly affects the responses in micro-turning operation. Moreover, the SEM results confirmed that abrasion and crater wear mechanism were observed during the micro-turning of a Ti6Al4V alloy.

Thin-walled micro-structures are a critical component of micro-devices, and their precise manufacture has a direct impact on product performance. Micro-milling is an effective manufacturing method that enables the production of micro-thin-walled structures with high precision and performance. Wall deformation is an undesirable problem in the production of parts with complex geometries and high aspect ratios, particularly when the height-to-thickness ratio (h/t) exceeds 20. In the micro-milling process, cutting parameters are the main factors affecting wall deformation. Therefore, optimising the cutting parameters is critical for the accuracy and precision of the cutting process. In this study, thin walls of 50 µm thickness, 1 mm height and 10 mm length were machined from an Al6061-T6 alloy using a tungsten carbide cutting tool with a diameter of 1 mm. The effects of feed rate, spindle speed and depth of cut cutting parameters (control parameters) used in the micro-milling process on the cutting forces and wall deformation (outputs) were investigated. A Taguchi L18 orthogonal design was used to optimise the cutting parameters. During the micro-milling experiments, the cutting forces were recorded, and the amount of deformation occurring in the thin wall was accurately determined using an optical profilometer with a motorised measuring system. Taguchi and ANOVA analyses were performed on the measured values of F_x tangential force, F_y feed force and thin-wall deformation to determine the effect of the control parameters on the outputs and to determine the most suitable cutting parameters to minimise deformation and keep the cutting forces under control. As a result of this study, the cutting parameter with the highest effect on the tangential force F_x was the depth of cut, with 56.94%, while the most effective cutting parameter on the feed force F_y was the feed rate, with 45.3%. The most effective parameter on the machined thin-wall deformation was the feed rate, with 87.36%. This study on the optimisation of cutting parameters in micro-thin-walled structures covers a unique topic that has been addressed in limited numbers in the literature.

Mikro tornalama işlemi, mikro silindirik parçaların imalatında kullanılan bir mikro işleme yöntemidir. Talaş derinliği ve ilerleme değeri çok küçük olması nedeniyle, iş parçasının tane boyutuna yakın değerlerinde kesme işlemleri yapılabilmektedir. Bu durumda, kesme kuvvetleri sadece iş parçasının türüne değil, aynı zamanda tane boyutuna, yüzeydeki artık gerilmelere ve tane yönlenmesine göre değişkenlik gösterir. Bu çalışmada mikro tornalama işleminde kesme kuvvetlerinin mekanistik modellemesi gerçekleştirilmiştir. Kesme deneyleri ortogonal şartlarda gerçekleştirilmiş ve iş parçası olarak Ti6Al4V alaşımı kullanılmıştır. Çalışmada farklı ilerleme değerleri kullanılarak kesme kuvveti katsayıları elde edilmiştir. Ayrıca çalışmada kullanılan DEFORM 2D ticari yazılımı ile nümerik modelleme yapılmış, kesme kuvveti katsayıları mekanistik model ile karşılaştırılmıştır. Kuvvet katsayılarının birbirleri ile uyumlu olduğu gözlenmiş, bu çalışmada kullanılan iş parçası ve takım çifti için kesme ve kenar kuvveti katsayıları elde edilmiştir. Sonuçların doğrulanmasını yapmak adına, elde edilen kesme ve kenar kuvveti katsayıları kullanılarak, farklı ilerleme değerleri ve yanaşma açılarında kesme kuvvetleri hesaplanmış ve bu sonuçlar arasındaki farkın kabul edilebilir düzeyde olduğu saptanmıştır. Micro turning is a micro machining method used in the manufacture of micro cylindrical parts. Because of the depth of cut and the feed rate is very small, cutting operations can be made at the values close to the grain size of the workpiece. In this case, the cutting forces vary not only according to the type of workpiece, but also according to grain size, residual stresses on the surface and grain orientation. In this study, mechanistic modelling of cutting forces in micro turning operation is performed. Cutting tests were carried out under orthogonal conditions and Ti6Al4V alloy was used as the workpiece. Cutting force coefficients were obtained by using different feed values. In addition, numerical modelling was performed with DEFORM 2D commercial software used in the study and cutting force coefficients were compared with mechanistic model. It was observed that the force coefficients were compatible with each other and cutting and edge force coefficients were obtained for the work piece and tool pair used in this study. In order to verify the results, using the obtained cutting and edge force coefficients, the cutting forces were calculated at different feed rates and approach angles, and the difference between these results was found to be at an acceptable level.

Micromilling is a helpful process empowering the fabrication of small-scale components characterized by complex geometries, heightened precision, and superior surface integrity. Widely embraced across aerospace, biomedical, and electronics sectors, it characterizes efficiency and sustainability in modern manufacturing paradigms. However, fundamental instabilities emerge during the cutting phase, particularly when the size effect diminishes below a critical threshold termed the minimum chip thickness, a parameter linked to the cutting-edge radius and feed rate dynamics. The micro-milling process enables the production of small-scale parts with complex geometries, high precision, and optimal surface quality. It stands as a preferred production method not only in the aerospace, biomedical, and electronics industries but also in the renewable energy sector, where its ability to create intricate components with precise dimensions and superior surface quality is crucial for optimizing efficiency and sustainability in energy harvesting and storage technologies. Instabilities are observed in the cutting process when the size effect falls below a critical value known as the minimum chip thickness. This critical value is related to the cutting-edge radius and feed rate. This study investigates the effect of size on surface roughness in micro-milling of Al6061-T6 workpiece. The results show that surface roughness is high at feed rates below the minimum chip thickness due to the ploughing mechanism. The shear mechanism is active at feed rates above the minimum chip thickness, but the ploughing effect is still observed at the 100µm edge of the cutting channel. The study revealed that surface roughness and height differences were high at feed rates significantly below or above the minimum chip thickness. However, surface quality was optimal at feed rates near the minimum chip thickness. Nevertheless, the study highlights an optimal peak in surface quality achieved at feed rates close to the minimum chip thickness, explaining a relationship between operational efficiency and sustainability in micro-milling endeavours.

Micro-thin-walled structures are frequently encountered in micro-pumps, micro-channel cooler plates, and micro-molds in the defense, aerospace and biomedical sectors. One of the micro-machining methods frequently used to obtain micro-thin-walled structures is micro-milling. The micro-milling method makes machining possible for micro-components with high accuracy and a good surface finish. However, there are many issues to consider when micro-milling thin-walled geometries. The fact that the wall deformation is directly related to the rate of progression necessitates knowing what effects the rate of progression cause on the wall deformation. Because the micro milling technique is generally used as the final cutting process in the creation of thin wall geometries in the industry. In this study, thin-walled structures were obtained by micro-milling the Al6061-T6 material. The influence of feed rate on wall deformation was investigated by applying different feed rates in micro milling experiments. Wall deformation measurements were performed using a motorized optical profilometer device. It has been observed that increasing feed value causes an enhance in cutting forces, it also causes an increase in the deformation of the micro-thin wall. The deformation distance between the end points of the micro-milled wall geometry using a feed rate of 1 µm/tooth is three times greater than the thin-wall geometry created using a feed rate of 0.2 µm/tooth. It has been determined that the deformation is much higher in the entrance and exit areas of the micro-thin wall. The wall deformation also decreases from the upper point to the lower points of the micro-thin wall. While the deviation distance in the measurement taken from the upper point of the wall geometry obtained by using the 1 µm/tooth feed rate, where the deformation is more, can reach 100 µm, the deviation at the lower point of the wall is negligible.

Tersine mühendislik, bir parçanın üretim sürecini, geriye doğru gerçekleştirme işlemidir. Tersine mühendisliğin amacı, mevcut bir CAD modeli olmadan, 3D model oluşturmaktır. Tersine mühendislik; üreticinin herhangi bir sebeple elinde bulunmayan, ürüne ait bilgisayar destekli tasarım modeline ulaşması için gerekli bir aşamadır. Bu çalışmada tersine mühendislik aşamaları anlatılmış ve makine mühendisliği alanındaki uygulamalarından bahsedilmiştir. Literatürdeki çalışmalar incelenmiş ve bu alandaki çalışmalar derlenmiştir. Bu alanda sıklıkla karşılaşılan birkaç tersine mühendislik işlemi ile ilgili detaylı bilgi verilmiştir. Çalışmada genel olarak tersine mühendislik sürecinin anlaşılması hedeflenmiş ve özellikle makine mühendisliği alanında, hangi durumlarda tersine mühendislik işlemine başvurulduğunun tespiti üzerinde durulmuştur. Böylece tersine mühendislik sürecinin makine sektöründe oldukça pratik ve verimli bir seçenek olduğu gözler önüne serilmiştir.