Ti(C,N) and WC-Based Cermets: A Review of Synthesis, Properties and Applications in Additive Manufacturing

In recent years, the use of cermets has shown significant growth in the industry due to their interesting features that combine properties of metals and ceramics, and there are different possible types of cermets, depending on their composition. This review focuses on cemented tungsten carbides (WC), and tungsten carbonitrides (WCN)), and it is intended to analyze the relationship between chemical composition and processing techniques of these materials, which results in their particular microstructural and mechanical properties. Moreover, the use of cermets as a printing material in additive manufacturing or 3D printing processes has recently emerged as one of the scenarios with the greatest projection, considering that they manufacture parts with greater versatility, lower manufacturing costs, lower raw material expenditure and with advanced designs. Therefore, this review compiled and analyzed scientific papers devoted to the synthesis, properties and uses of cermets of TiC and WC in additive manufacturing processes reported thus far.

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Additive Manufacturing Techniques for the Reconstruction of 3D Fetal Faces

Applied Bionics and Biomechanics ◽

10.1155/2017/9701762 ◽

2017 ◽

Vol 2017 ◽

pp. 1-10 ◽

Cited By ~ 11

Author(s):

Domenico Speranza ◽

Daniela Citro ◽

Francesco Padula ◽

Barbara Motyl ◽

Federica Marcolin ◽

...

Keyword(s):

Additive Manufacturing ◽

Medical Image ◽

Cleft Lip ◽

3D Models ◽

3D Ultrasound ◽

Point Of View ◽

Fetal Malformations ◽

Manufacturing Techniques ◽

Processing Techniques ◽

The Relationship

This paper deals with additive manufacturing techniques for the creation of 3D fetal face models starting from routine 3D ultrasound data. In particular, two distinct themes are addressed. First, a method for processing and building 3D models based on the use of medical image processing techniques is proposed. Second, the preliminary results of a questionnaire distributed to future parents consider the use of these reconstructions both from an emotional and an affective point of view. In particular, the study focuses on the enhancement of the perception of maternity or paternity and the improvement in the relationship between parents and physicians in case of fetal malformations, in particular facial or cleft lip diseases.

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Sodium Metasilicate Cemented Analogue Material and Its Mechanical Properties

Advances in Materials Science and Engineering ◽

10.1155/2016/3716145 ◽

2016 ◽

Vol 2016 ◽

pp. 1-17 ◽

Cited By ~ 2

Author(s):

Songlin Yue ◽

Yanyu Qiu ◽

Pengxian Fan ◽

Pin Zhang ◽

Ning Zhang

Keyword(s):

Complex Geometry ◽

Sodium Metasilicate ◽

Raw Material ◽

Fine Aggregate ◽

Regression Equations ◽

Deformation And Failure ◽

Orthogonal Experiments ◽

Low Modulus ◽

New Type ◽

The Relationship

Analogue material with appropriate properties is of great importance to the reliability of geomechanical model test, which is one of the mostly used approaches in field of geotechnical research. In this paper, a new type of analogue material is developed, which is composed of coarse aggregate (quartz sand and/or barite sand), fine aggregate (barite powder), and cementitious material (anhydrous sodium silicate). The components of each raw material are the key influencing factors, which significantly affect the physical and mechanical parameters of analogue materials. In order to establish the relationship between parameters and factors, the material properties including density, Young’s modulus, uniaxial compressive strength, and tensile strength were investigated by a series of orthogonal experiments with hundreds of samples. By orthogonal regression analysis, the regression equations of each parameter were obtained based on experimental data, which can predict the properties of the developed analogue materials according to proportions. The experiments and applications indicate that sodium metasilicate cemented analogue material is a type of low-strength and low-modulus material with designable density, which is insensitive to humidity and temperature and satisfies mechanical scaling criteria for weak rock or soft geological materials. Moreover, the developed material can be easily cast into structures with complex geometry shapes and simulate the deformation and failure processes of prototype rocks.

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Prediction of Maritime Pine Boards Modulus of Elasticity by Means of Sonic Testing on Green Timber

Applied Sciences ◽

10.3390/app11041748 ◽

2021 ◽

Vol 11 (4) ◽

pp. 1748

Author(s):

Giovanna Concu

Keyword(s):

Modulus Of Elasticity ◽

Structural Timber ◽

Maritime Pine ◽

Manufacturing Costs ◽

Sonic Waves ◽

Wet Condition ◽

Structural Grade ◽

The Relationship ◽

Grade Yield

Timber buildings are experiencing a rapid diffusion due to their good performance and their sustainability; however, some steps of structural timber production process, such as drying, are energy-intensive and environmentally impactful, and many wood species are also affected by low yield. Therefore, it would be important to determine the quality of the green material, that is, in wet condition, before undergoing the most impactful and expensive production steps. This paper describes a research aimed at quantifying the variation of the dynamic modulus of elasticity MoEdyn, which is commonly used for structural timber mechanical grading, from wet to dry condition in Sardinian maritime pine boards to be used for the production of laminated timber, and to examine the relationship between wet and dry MoEdyn. The MoEdyn was determined from measurements of the velocity of sonic waves propagating through the boards. The results show that the dry MoEdyn can be estimated starting from boards sonic testing in the wet condition, so providing a basis for implementing Sardinian maritime pine pre-grading in order to obtain the reduction of manufacturing costs, the abatement of environmental impact, and the increase of structural grade yield.

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Improving surface quality in selective laser melting based tool making

Journal of Intelligent Manufacturing ◽

10.1007/s10845-021-01744-9 ◽

2021 ◽

Author(s):

Filippo Simoni ◽

Andrea Huxol ◽

Franz-Josef Villmer

Keyword(s):

Surface Roughness ◽

Additive Manufacturing ◽

Surface Quality ◽

Selective Laser Melting ◽

Melting Process ◽

Laser Remelting ◽

Laser Melting ◽

Great Cost ◽

Starting Point ◽

Processing Techniques

AbstractIn the last years, Additive Manufacturing, thanks to its capability of continuous improvements in performance and cost-efficiency, was able to partly replace and redefine well-established manufacturing processes. This research is based on the idea to achieve great cost and operational benefits especially in the field of tool making for injection molding by combining traditional and additive manufacturing in one process chain. Special attention is given to the surface quality in terms of surface roughness and its optimization directly in the Selective Laser Melting process. This article presents the possibility for a remelting process of the SLM parts as a way to optimize the surfaces of the produced parts. The influence of laser remelting on the surface roughness of the parts is analyzed while varying machine parameters like laser power and scan settings. Laser remelting with optimized parameter settings considerably improves the surface quality of SLM parts and is a great starting point for further post-processing techniques, which require a low initial value of surface roughness.

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Comparison of the Effects of Conching Parameters on the Contents of Three Dominant Flavan3-ols, Rheological Properties and Sensory Quality in Chocolate Milk Mass Based on Liquor from Unroasted Cocoa Beans

Molecules ◽

10.3390/molecules26092502 ◽

2021 ◽

Vol 26 (9) ◽

pp. 2502

Author(s):

Bogumiła Urbańska ◽

Hanna Kowalska ◽

Karolina Szulc ◽

Małgorzata Ziarno ◽

Irina Pochitskaya ◽

...

Keyword(s):

Rheological Properties ◽

Yield Stress ◽

Sensory Quality ◽

Raw Material ◽

Antioxidant Compounds ◽

Chocolate Milk ◽

Cocoa Beans ◽

Variable Parameters ◽

The Relationship ◽

Manufacturing Parameters

The content of polyphenols in chocolate depends on many factors related to the properties of raw material and manufacturing parameters. The trend toward developing chocolates made from unroasted cocoa beans encourages research in this area. In addition, modern customers attach great importance to how the food they consume benefits their bodies. One such benefit that consumers value is the preservation of natural antioxidant compounds in food products (e.g., polyphenols). Therefore, in our study we attempted to determine the relationship between variable parameters at the conching stage (i.e., temperature and time of) and the content of dominant polyphenols (i.e.,catechins, epicatechins, and procyanidin B2) in chocolate milk mass (CMM) obtained from unroasted cocoa beans. Increasing the conching temperature from 50 to 60 °C decreased the content of three basic flavan-3-ols. The highest number of these compounds was determined when the process was carried out at 50 °C. However, the time that caused the least degradation of these compounds differed. For catechin, it was 2 h; for epicatechin it was 1 h; and for procyanidin it was 3 h. The influence of both the temperature and conching time on the rheological properties of chocolate milk mass was demonstrated. At 50 °C, the viscosity and the yield stress of the conched mass showed its highest value.

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A Scientometric Approach to Review the Role of the Medial Preoptic Area (MPOA) in Parental Behavior

Brain Sciences ◽

10.3390/brainsci11030393 ◽

2021 ◽

Vol 11 (3) ◽

pp. 393

Author(s):

Alessandro Carollo ◽

Jan Paolo Macapinlac Balagtas ◽

Michelle Jin-Yee Neoh ◽

Gianluca Esposito

Keyword(s):

Preoptic Area ◽

Parental Behavior ◽

Neural Substrates ◽

Medial Preoptic Area ◽

Brain Network ◽

Scientometric Analysis ◽

Parental Behaviour ◽

Scientific Papers ◽

The Relationship

Research investigating the neural substrates underpinning parental behaviour has recently gained momentum. Particularly, the hypothalamic medial preoptic area (MPOA) has been identified as a crucial region for parenting. The current study conducted a scientometric analysis of publications from 1 January 1972 to 19 January 2021 using CiteSpace software to determine trends in the scientific literature exploring the relationship between MPOA and parental behaviour. In total, 677 scientific papers were analysed, producing a network of 1509 nodes and 5498 links. Four major clusters were identified: “C-Fos Expression”, “Lactating Rat”, “Medial Preoptic Area Interaction” and “Parental Behavior”. Their content suggests an initial trend in which the properties of the MPOA in response to parental behavior were studied, followed by a growing attention towards the presence of a brain network, including the reward circuits, regulating such behavior. Furthermore, while attention was initially directed uniquely to maternal behavior, it has recently been extended to the understanding of paternal behaviors as well. Finally, although the majority of the studies were conducted on rodents, recent publications broaden the implications of previous documents to human parental behavior, giving insight into the mechanisms underlying postpartum depression. Potential directions in future works were also discussed.

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Wire Arc Additive Manufacturing: Review on Recent Findings and Challenges in Industrial Applications and Materials Characterization

Metals ◽

10.3390/met11060939 ◽

2021 ◽

Vol 11 (6) ◽

pp. 939

Author(s):

Mukti Chaturvedi ◽

Elena Scutelnicu ◽

Carmen Catalina Rusu ◽

Luigi Renato Mistodie ◽

Danut Mihailescu ◽

...

Keyword(s):

Additive Manufacturing ◽

Structural Integrity ◽

Industrial Applications ◽

Raw Material ◽

Continuous Increase ◽

Control Optimization ◽

Modern Manufacturing ◽

Directed Energy ◽

Manufacturing Technologies ◽

Wire Arc Additive Manufacturing

Wire arc additive manufacturing (WAAM) is a fusion manufacturing process in which the heat energy of an electric arc is employed for melting the electrodes and depositing material layers for wall formation or for simultaneously cladding two materials in order to form a composite structure. This directed energy deposition-arc (DED-arc) method is advantageous and efficient as it produces large parts with structural integrity due to the high deposition rates, reduced wastage of raw material, and low consumption of energy in comparison with the conventional joining processes and other additive manufacturing technologies. These features have resulted in a constant and continuous increase in interest in this modern manufacturing technique which demands further studies to promote new industrial applications. The high demand for WAAM in aerospace, automobile, nuclear, moulds, and dies industries demonstrates compatibility and reflects comprehensiveness. This paper presents a comprehensive review on the evolution, development, and state of the art of WAAM for non-ferrous materials. Key research observations and inferences from the literature reports regarding the WAAM applications, methods employed, process parameter control, optimization and process limitations, as well as mechanical and metallurgical behavior of materials have been analyzed and synthetically discussed in this paper. Information concerning constraints and enhancements of the wire arc additive manufacturing processes to be considered in terms of wider industrial applicability is also presented in the last part of this paper.

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Synthesis of DHA/EPA Ethyl Esters via Lipase-Catalyzed Acidolysis Using Novozym® 435: A Kinetic Study

Catalysts ◽

10.3390/catal10050565 ◽

2020 ◽

Vol 10 (5) ◽

pp. 565 ◽

Cited By ~ 3

Author(s):

Chia-Hung Kuo ◽

Chun-Yung Huang ◽

Chien-Liang Lee ◽

Wen-Cheng Kuo ◽

Shu-Ling Hsieh ◽

...

Keyword(s):

Ethyl Ester ◽

Ethyl Esters ◽

Raw Material ◽

Maximum Reaction Rate ◽

Mechanism Model ◽

Maximum Reaction ◽

Substrate Ratio ◽

Free Fatty Acid Form ◽

The Relationship ◽

Predictive Relationship

DHA/EPA ethyl ester is mainly used in the treatment of arteriosclerosis and hyperlipidemia. In this study, DHA+EPA ethyl ester was synthesized via lipase-catalyzed acidolysis of ethyl acetate (EA) with DHA+EPA concentrate in n-hexane using Novozym® 435. The DHA+EPA concentrate (in free fatty acid form), contained 54.4% DHA and 16.8% EPA, was used as raw material. A central composite design combined with response surface methodology (RSM) was used to evaluate the relationship between substrate concentrations and initial rate of DHA+EPA ethyl ester production. The results indicated that the reaction followed the ordered mechanism and as such, the ordered mechanism model was used to estimate the maximum reaction rate (Vmax) and kinetic constants. The ordered mechanism model was also combined with the batch reaction equation to simulate and predict the conversion of DHA+EPA ethyl ester in lipase-catalyzed acidolysis. The integral equation showed a good predictive relationship between the simulated and experimental results. 88–94% conversion yields were obtained from 100–400 mM DHA+EPA concentrate at a constant enzyme activity of 200 U, substrate ratio of 1:1 (DHA+EPA: EA), and reaction time of 300 min.

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Dependency in Africa: Stages of African Political Economy

Alternatives Global Local Political ◽

10.1177/030437548300900203 ◽

1983 ◽

Vol 9 (2) ◽

pp. 229-247 ◽

Cited By ~ 2

Author(s):

Amechi Okolo

Keyword(s):

Political Economy ◽

International System ◽

Raw Material ◽

The West ◽

Cheap Labour ◽

History Of ◽

The Common ◽

First Contact ◽

The Impact ◽

The Relationship

This paper traces the history of the relationship between Africa and the West since their first contact brought about by the outward thrust of the West, under the impetus of rising capitalism, in search of cheap labour and cheap raw material for its industries and expanding markets for its industrial products, both of which could be better ensured through domination and exploitation. The paper identifies five successive stages that African political economy has passed through under the impact of this relationship, each phase qualitatively different from the other but all having the common characteristic of domination-dependence syndrome, and each phase having been dictated by the dynamics of capitalism in different eras and by the dominant forces in the changing international system. Its finding is that the way to the latest stage, the dependency phase, was paved by the progressive proletarianization of the African peoples and the maintenance of an international peonage system. It ends by indicating the direction in which Africa can make a beginning to break out of dependency and achieve liberation.

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Material Properties and Design Aspects of Folding Bicycle Frame

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.264-265.777 ◽

2011 ◽

Vol 264-265 ◽

pp. 777-782 ◽

Cited By ~ 2

Author(s):

M.A. Maleque ◽

M.S. Hossain ◽

S. Dyuti

Keyword(s):

Material Properties ◽

Raw Material ◽

New Materials ◽

Materials Properties ◽

Advantages And Disadvantages ◽

Bicycle Frame ◽

Successful Design ◽

Future Direction ◽

The Relationship ◽

Comprehensive Study

successful design of folding bicycle should take into account the function, material properties, and fabrication process. There are some other factors that should be considered in anticipating the behavior of materials for folding bicycle. In order to understand the relationship between material properties and design of a folding bicycle and also for the future direction in new materials with new design, a comprehensive study on the design under different conditions are essential. Therefore, a systematic study on the relationship between material properties and design for folding bicycle has been performed. The advantages and disadvantages matrix between conventional bicycle and folding bicycle is presented for better understanding of the materials properties and design. It was found that the materials properties of the folding bicycle frame such as fatigue and tensile strength are the important properties for the better performance of the frame. The relationship between materials properties and design is not straight forward because the behavior of the material in the finished product could be different from that of the raw material. The swing hinge technique could be a better technique in the design for the folding bicycle frame.

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