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With the development of new industries and technological processes, the use of pure materials in sophisticated applications is decreasing due to the demand of conflicting property requirements in single component. The interest on functionally graded ceramics (FGCs) that can be used under severe service conditions with high reliability has increased parallel to demand on complex advanced ceramics in various applications. Conventional methods are not totally capable of cost-effective fabrication of near-net shape FGCs with flexible and complex gradient designs. Lithography-based ceramic manufacturing (LCM) is an additive manufacturing (AM) method that works according to the principle of selective curing of photosensitive formulation according to the digital light processing (DLP) concept. The recently developed LCM multi-material printer allows fabrication of ceramic-ceramic and metal-ceramic combinations with high dimensional precision. Printing methodologies were developed to manufacture FGCs that show both discrete and continuous porosity gradient in parallel and perpendicular to deposition direction. FGC combinations were produced by developing suitable suspensions, optimizing the debinding and sintering processes according to the single material thermo-elastic properties, design, and optimization of printing processes. The main challenges and possible future possibilities in realization of FGCs by LCM will be presented., Journal of Additive Manufacturing Technologies, Vol. 2 No. 1 (2022): J AM Tech

Failure probability of ceramic components in multiaxial stress state can be predicted using the uniaxial test results (e.g. tension test, 4-point-bending test) when a suitable multiaxial criterion, which introduces the triaxiality of stress state, is known. In this article, tension–torsion tests were performed with alumina (Alsint 99.7) specimens from a standard manufacturer under two different load cases. Next experimental results were compared with the numerically calculated effective volume and effective surface values according to different multiaxial failure criteria. It was concluded that the specimens failed due to surface flaws and the normal stress criterion is the most appropriate criterion for the strength prediction of alumina ceramics under multiaxial stress state. Furthermore, it was shown that the Weibull modulus does not play a big role for the prediction of strength of alumina ceramics.

Görüntü İşleme Yöntemi, dokunmamış kumaşların boncuklaşma eğilimi ve dokuma ve örme kumaşlarda hasar tespiti gibi tekstil uygulamalarında yaygın olarak kullanılmaktadır. Görüntü işleme yöntemi ile kumaş ağırlığının tahmin edilmesi ile ilgili literatürde birçok çalışma bulunmaktadır. Fakat görüntü işleme yöntemi kullanılarak çekme mukavemeti ve kopma uzamasının kumaşlarda tahmini konusu çok az sayıda makalede işlenmiştir. Bu makalede, farklı ağırlıktaki polipropilen spunbond dokunmamış kumaşların (12g/m2, 20g/m2, 25g/m2, 30g/m2, 50g/m2) ağırlık, çekme mukavemeti ve kopma uzaması özelliklerinin görüntü işleme yöntemi ile tahmin edilmesi incelenmektedir. Deneysel sonuçlar ile makalede önerilen istatistiksel yöntemle tahmin edilen kumaş özellikleri karşılaştırılacaktır. Bu makalede incelenen bağıntılar yardımıyla, çekme mukavemeti cihazına sahip olmayan polipropilen spunbond dokunmamış kumaş üretim fabrikaları üretim sırasında kumaşların çekme mukavemetlerini ve kopma uzamalarını tahmin edebileceklerdir, Digital image analysis is widely used in textile applications including fabric pilling behavior of nonwovens and defect detections in woven and knitted fabrics to predict some properties and online control of the quality of nonwoven materials. The estimation of fabric weight using digital image analysis is well established in the literature. But little information could be found about the estimation of grab tensile strength and elongation at break using digital image analysis. This paper investigates the estimation of weight, tensile strength and elongation at break values of polypropylene (PP) spunbond nonwoven fabrics at various weights (12g/m2, 20g/m2, 25g/m2, 30g/m2, 50g/m2) using digital image analysis. The relationships between the experimentally measured material properties and statistical parameters computed using digital image analysis is introduced. With the help of the correlations provided in this article, PP spunbond fabric production companies, which do not have tensile testing device, could roughly estimate the grab tensile strength and elongation at break values of the PP fabrics

Functionally Graded Materials (FGMs) offer discrete or continuously changing properties/compositions over the volume of the parts. The widespread application of FGMs was not rapid enough in the past due to limitations of the manufacturing methods. Significant developments in manufacturing technologies especially in Additive Manufacturing (AM) enable us nowadays to manufacture materials with specified changes over the volume/surface of components. The use of AM methods for the manufacturing of FGMs may allow us to compensate for some drawbacks of conventional methods and to produce complex and near-net-shaped structures with better control of gradients in a cost-efficient way. Vat Photopolymerization (VP), a type of AM method that works according to the principle of curing liquid photopolymer resin layer-by-layer, has gained in recent years high importance due to its advantages such as low cost, high surface quality control, no need to support structures, no limitation in the material. This article reviews the state-of-art and future potential of using VP methods for FGM manufacturing. It was concluded that improvements in printer hardware setup and software, design aspects and printing methodologies will accelerate the use of VP methods for FGMs manufacturing.

0000-0002-1145-6471 WOS:000576363800001 Today, many quality controls processes that are controlled by Image Processing (IP) technique has achieved state-of-the-art performance for all technology field. The image processing technique, which provides as accurate objective evaluation as the long and tiring traditional measurement methods, is nowadays widely used in textile industry. In this study, an alternative image processing technique has been proposed against the conventional wickability measurement method of nonwoven fabrics especially used in the hygiene products. An average liquid spread area ratio of airlaid nonwoven fabric was calculated with the developed algorithm and the accuracy of the proposed technology was demonstrated.