Research

15 pages, 7238 KiB

Open AccessArticle

Decision Support Tool in the Selection of Powder for 3D Printing

by Ewelina Szczupak, Marcin Małysza, Dorota Wilk-Kołodziejczyk, Krzysztof Jaśkowiec, Adam Bitka, Mirosław Głowacki and Łukasz Marcjan

Materials 2024, 17(8), 1873; https://doi.org/10.3390/ma17081873 - 18 Apr 2024

Viewed by 182

Abstract

The work presents a tool enabling the selection of powder for 3D printing. The project focused on three types of powders, such as steel, nickel- and cobalt-based and aluminum-based. An important aspect during the research was the possibility of obtaining the mechanical parameters. [...] Read more.

The work presents a tool enabling the selection of powder for 3D printing. The project focused on three types of powders, such as steel, nickel- and cobalt-based and aluminum-based. An important aspect during the research was the possibility of obtaining the mechanical parameters. During the work, the possibility of using the selected algorithm based on artificial intelligence like Random Forest, Decision Tree, K-Nearest Neighbors, Fuzzy K-Nearest Neighbors, Gradient Boosting, XGBoost, AdaBoost was also checked. During the work, tests were carried out to check which algorithm would be best for use in the decision support system being developed. Cross-validation was used, as well as hyperparameter tuning using different evaluation sets. In both cases, the best model turned out to be Random Forest, whose F1 metric score is 98.66% for cross-validation and 99.10% after tuning on the test set. This model can be considered the most promising in solving this problem. The first result is a more accurate estimate of how the model will behave for new data, while the second model talks about possible improvement after optimization or possible overtraining to the parameters. Full article

(This article belongs to the Special Issue Research and Development in the World Foundry Engineering: Materials, Properties and Applications)

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21 pages, 14659 KiB

Open AccessArticle

Evaluation of Microstructure and Abrasive Wear-Resistance of Medium Alloy SiMo Ductile Cast Iron

by Łukasz Dyrlaga, Renata Zapała, Krzysztof Morgiel, Andrzej Studnicki, Andrzej Szczęsny and Dariusz Kopyciński

Materials 2024, 17(5), 1223; https://doi.org/10.3390/ma17051223 - 06 Mar 2024

Viewed by 485

Abstract

Medium-alloy ductile iron with a SiMo ferritic matrix has very good heat resistance. The addition of chromium and aluminum also increases this resistance. This article presents the impact of chromium and aluminum on the structure of SiMo cast iron, especially their impact on [...] Read more.

Medium-alloy ductile iron with a SiMo ferritic matrix has very good heat resistance. The addition of chromium and aluminum also increases this resistance. This article presents the impact of chromium and aluminum on the structure of SiMo cast iron, especially their impact on the deformation of the spherical graphite precipitates and the formation of M₆C and M₃C₂ carbide phases. These carbides are formed in a ferritic matrix or at the grain boundaries, resulting in increased hardness and a drastic reduction in impact strength. The article presents the influence of heat treatment on the material’s microstructure and resistance to abrasive wear. Chromium and aluminum additions can also indirectly reduce the abrasive wear resistance of SiMo cast iron. The presented research shows the possibility of doubling the abrasive wear resistance of SiMo cast iron. Full article

(This article belongs to the Special Issue Research and Development in the World Foundry Engineering: Materials, Properties and Applications)

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16 pages, 2692 KiB

Open AccessArticle

Prediction of the Secondary Arms Spacing Based on Dendrite Tip Kinetics and Cooling Rate

by Ibrahim Sari, Mahmoud Ahmadein, Sabbah Ataya, Lakhdar Hachani, Kader Zaidat, Nashmi Alrasheedi, Menghuai Wu and Abdellah Kharicha

Materials 2024, 17(4), 865; https://doi.org/10.3390/ma17040865 - 13 Feb 2024

Cited by 1 | Viewed by 566

Abstract

Secondary dendrite arm spacing (SDAS) is one of the most important factors affecting macrosegregation and mechanical properties in solidification processes. Predicting SDAS is one of the major parameters in foundry technology. In order to predict the evolution of microstructures during the solidification process, [...] Read more.

Secondary dendrite arm spacing (SDAS) is one of the most important factors affecting macrosegregation and mechanical properties in solidification processes. Predicting SDAS is one of the major parameters in foundry technology. In order to predict the evolution of microstructures during the solidification process, we proposed a simple model which predicted the secondary dendrite arm spacing based solely on the tip velocity (related to the tip supersaturation) and cooling rate. The model consisted of a growing cylinder inside a liquid cylindrical envelope. Two important hypotheses were made: (1) Initially the cylinder radius was assumed to equal the dendrite tip radius and (2) the cylindrical envelope had a fixed radius in the order of the dendrite tip diffusion length. The numerical model was tested against experiments using various Pb–Sn alloys for a fixed temperature gradient. The results were found to be in excellent agreement with experimental measurements in terms of SDAS and dendrite tip velocity prediction. This simple model is naturally destined to be implemented as a sub-grid model in volume-averaging models to predict the local microstructure, which in turn directly controls the mushy zone permeability and macrosegregation phenomena. Full article

(This article belongs to the Special Issue Research and Development in the World Foundry Engineering: Materials, Properties and Applications)

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Graphical abstract

13 pages, 16053 KiB

Open AccessArticle

Analysis of the Possibility of Using Selected Tools and Algorithms in the Classification and Recognition of Type of Microstructure

by Michał Szatkowski, Dorota Wilk-Kołodziejczyk, Krzysztof Jaśkowiec, Marcin Małysza, Adam Bitka and Mirosław Głowacki

Materials 2023, 16(21), 6837; https://doi.org/10.3390/ma16216837 - 24 Oct 2023

Viewed by 688

Abstract

The aim of this research was to develop a solution based on existing methods and tools that would allow the automatic classification of selected images of cast iron microstructures. As part of the work, solutions based on artificial intelligence were tested and modified. [...] Read more.

The aim of this research was to develop a solution based on existing methods and tools that would allow the automatic classification of selected images of cast iron microstructures. As part of the work, solutions based on artificial intelligence were tested and modified. Their task is to assign a specific class in the analyzed microstructure images. In the analyzed set, the examined samples appear in various zoom levels, photo sizes and colors. As is known, the components of the microstructure are different. In the examined photo, there does not have to be only one type of precipitate in each photo that indicates the correct microstructure of the same type of alloy, different shapes may appear in different amounts. This article also addresses the issue of data preparation. In order to isolate one type of structure element, the possibilities of using methods such as HOG (histogram of oriented gradients) and thresholding (the image was transformed into black objects on a white background) were checked. In order to avoid the slow preparation of training data, our solution was proposed to facilitate the labeling of data for training. The HOG algorithm combined with SVM and random forest were used for the classification process. In order to compare the effectiveness of the operation, the Faster R-CNN and Mask R-CNN algorithms were also used. The results obtained from the classifiers were compared to the microstructure assessment performed by experts. Full article

(This article belongs to the Special Issue Research and Development in the World Foundry Engineering: Materials, Properties and Applications)

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14 pages, 2307 KiB

Open AccessArticle

The Influence of 3D Printing Core Construction (Binder Jetting) on the Amount of Generated Gases in the Environmental and Technological Aspect

by Artur Bobrowski, Faustyna Woźniak, Sylwia Żymankowska-Kumon, Karolina Kaczmarska, Beata Grabowska, Michał Dereń and Robert Żuchliński

Materials 2023, 16(16), 5507; https://doi.org/10.3390/ma16165507 - 08 Aug 2023

Cited by 1 | Viewed by 813

Abstract

This article presents the findings of a study focusing on the gas generation of 3D-printed cores fabricated using binder-jetting technology with furfuryl resin. The research aimed to compare gas emission levels, where the volume generated during the thermal degradation of the binder significantly [...] Read more.

This article presents the findings of a study focusing on the gas generation of 3D-printed cores fabricated using binder-jetting technology with furfuryl resin. The research aimed to compare gas emission levels, where the volume generated during the thermal degradation of the binder significantly impacts the propensity for gaseous defects in foundries. The study also investigated the influence of the binder type (conventional vs. 3D-printed dedicated binder) and core construction (shell core) on the quantity of gaseous products from the BTEX group formed during the pouring of liquid foundry metal into the cores. The results revealed that the emitted gas volume during the thermal decomposition of the organic binder depended on the core sand components and binder type. Cores produced using conventional methods emitted the least gases due to lower binder content. Increasing Kaltharz U404 resin to 1.5 parts by weight resulted in a 37% rise in gas volume and 27% higher benzene emission. Adopting shell cores reduced gas volume by over 20% (retaining sand with hardener) and 30% (removing sand with hardener), presenting an eco-friendly solution with reduced benzene emissions and core production costs. Shell cores facilitated the quicker removal of gaseous binder decomposition products, reducing the likelihood of casting defects. The disparity in benzene emissions between 3D-printed and vibratory-mixed solid cores is attributed to the sample preparation process, wherein 3D printing ensured greater uniformity. Full article

(This article belongs to the Special Issue Research and Development in the World Foundry Engineering: Materials, Properties and Applications)

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13 pages, 5183 KiB

Open AccessArticle

Evaluation of Effect of Ti Addition to Zinc Bath on Kinetics of Growth of Alloy Layer Formed in Process of Hot-Dip Galvanisation on Steel Substrate

by Karolina Bracka-Kęsek, Andrzej Szczęsny, Edward Guzik and Dariusz Kopyciński

Materials 2023, 16(13), 4773; https://doi.org/10.3390/ma16134773 - 01 Jul 2023

Cited by 2 | Viewed by 786

Abstract

Faced with the raw material crisis in Zn resources, researchers are facing the challenge of developing technology for producing zinc coatings that are thinner than those that have been produced to date. This would make it possible to reduce Zn consumption in the [...] Read more.

Faced with the raw material crisis in Zn resources, researchers are facing the challenge of developing technology for producing zinc coatings that are thinner than those that have been produced to date. This would make it possible to reduce Zn consumption in the hot-dip galvanisation process. The study included an experiment that involved dip galvanising steel samples in baths of different Ti concentrations; this process was carried out at 450 °C and 550 °C. The use of this additive made it possible to reduce the growth of the alloy layer in the obtained zinc coatings. Using an optical microscope, observations were made of the microstructures of the resulting coatings, which made it possible to determine the thickness of the alloy layer in the coating. Thanks to the use of scanning electron microscopy with EDS analysis, however, it was possible to plot the chemical composition of the studied coatings and accurately observe the morphology of the formed phases. An intermetallic Zn-Fe-Ti phase was observed in the coatings formed in a Ti-added bath, which can affect the growth inhibition of the alloy layer in the zinc coating. Full article

(This article belongs to the Special Issue Research and Development in the World Foundry Engineering: Materials, Properties and Applications)

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17 pages, 9032 KiB

Open AccessArticle

Analyze the Wear Mechanism of the Longwall Shearer Haulage System

by Krzysztof Jaśkowiec, Zenon Pirowski, Mirosław Głowacki, Magdalena Bisztyga-Szklarz, Adam Bitka, Marcin Małysza and Dorota Wilk-Kołodziejczyk

Materials 2023, 16(8), 3090; https://doi.org/10.3390/ma16083090 - 13 Apr 2023

Cited by 2 | Viewed by 1274

Abstract

The wear characteristics and related mechanisms of the Longwall Shearer Haulage System were investigated. Wear is one of the main reasons for failures and downtimes. This knowledge can help solve engineering problems. The research was carried out at a laboratory station and a [...] Read more.

The wear characteristics and related mechanisms of the Longwall Shearer Haulage System were investigated. Wear is one of the main reasons for failures and downtimes. This knowledge can help solve engineering problems. The research was carried out at a laboratory station and a test stand. The publication presents the results of tribological tests carried out in laboratory conditions. The aim research was to select the alloy intended for casting the toothed segments of the haulage system. The track wheel was made by the forging method using steel 20H2N4A. Haulage System was tested on the ground using a longwall shearer. Selected toothed segments were subjected to tests on this stand. The cooperation of the track wheel and toothed segments in the tootbar were analyzed by a 3D scanner. Debris chemical composition was also appointed, as well as mass loss of toothed segments. The developed solution toothed segment an increase in the service life of the track wheel in real conditions. The results of the research also contribute to reducing the operating costs of the mining process. Full article

(This article belongs to the Special Issue Research and Development in the World Foundry Engineering: Materials, Properties and Applications)

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11 pages, 8412 KiB

Open AccessArticle

A Novel Approach of Optimum Time Interval Estimation for Al-7.5Si/Al-18Si Liquid–Liquid Bimetal Casting in Sand and Metallic Moulds

by Naglaa Fathy, Mohamed Ramadan, Khalid M. Hafez, Fahad Abdulaziz, Badreddine Ayadi and Abdulaziz S. Alghamdi

Materials 2023, 16(8), 3004; https://doi.org/10.3390/ma16083004 - 10 Apr 2023

Viewed by 978

Abstract

This work describes a novel approach for Al-7.5Si/Al-18Si liquid–liquid bimetal casting in sand and metallic moulds. The aim of the work is to facilitate and develop a simple procedure to produce an Al-7.5Si/Al-18Si bimetallic material with a smooth gradient interface structure. The procedure [...] Read more.

This work describes a novel approach for Al-7.5Si/Al-18Si liquid–liquid bimetal casting in sand and metallic moulds. The aim of the work is to facilitate and develop a simple procedure to produce an Al-7.5Si/Al-18Si bimetallic material with a smooth gradient interface structure. The procedure involves the theoretical calculation of total solidification time (TST) of the first liquid metal (M1), pouring the liquid metal (M1), and allowing it to solidify; then, before complete solidification, the second liquid metal (M2) is introduced into the mould. This novel approach has been proven to produce Al-7.5Si/Al-18Si bimetal materials using liquid–liquid casting. The optimum time interval of Al-7.5Si/Al-18Si bimetal casting with modulus of cast M_c ≤ 1 was estimated based on subtracting 5–15 s or 1–5 s from TST of M1 for sand and metallic moulds, respectively. Future work will involve determining the appropriate time interval range for castings having modulus ≥ 1 using the current approach. Full article

(This article belongs to the Special Issue Research and Development in the World Foundry Engineering: Materials, Properties and Applications)

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16 pages, 3813 KiB

Open AccessArticle

A Novel Hydro-Thermal Synthesis of Nano-Structured Molybdenum-Iron Intermetallic Alloys at Relatively Low Temperatures

by A. A. El-Geassy, K. S. Abdel Halim and Abdulaziz S. Alghamdi

Materials 2023, 16(7), 2736; https://doi.org/10.3390/ma16072736 - 29 Mar 2023

Cited by 8 | Viewed by 1219

Abstract

Nano-structured Mo/Fe intermetallics were synthesized from precursors that contained 72/28% and 30/70% molar ratios of Mo/Fe, which were given as precursors A and B, respectively. These precursors were prepared from the co-precipitation of aqueous hot solutions of ammonium heptamolybdate tetrahydrate (AHM) and ferrous [...] Read more.

Nano-structured Mo/Fe intermetallics were synthesized from precursors that contained 72/28% and 30/70% molar ratios of Mo/Fe, which were given as precursors A and B, respectively. These precursors were prepared from the co-precipitation of aqueous hot solutions of ammonium heptamolybdate tetrahydrate (AHM) and ferrous oxalate. The dry precipitates were thermally treated using TG-DSC to follow up their behavior during roasting, in an Ar atmosphere of up to 700 °C (10° K/min). The TG profile showed that 32.5% and 55.5% weight losses were measured from the thermal treatment of precursors A and B, respectively. The DSC heat flow profile showed the presence of endothermic peaks at 196.9 and 392.5–400 °C during the thermal decomposition of the AHM and ferrous oxalate, respectively. The exothermic peak that was detected at 427.5 °C was due to the production of nano-sized iron molybdate [Fe₂(MoO₄)₃]. An XRD phase analysis indicated that iron molybdate was the only phase that was identified in precursor A, while iron molybdate and Fe₂O₃ were produced in precursor B. Compacts were made from the pressing of the nano-sized precursors, which were roasted at 500 °C for 3 h. The roasted compacts were isothermally reduced in H₂ at 600–850 °C using microbalance, and the O₂ weight loss that resulted from the reduction reactions was continuously recorded as a function of time. The influence of the reduction temperature and precursor composition on the reduction behavior of the precursors was studied and discussed. The partially and completely reduced compacts were examined with X-ray powder diffraction (XRD), a reflected light microscope (RLM), and a scanning electron microscope (SEM-EDS). Depending on the precursor composition, the reduction reactions of the [Fe₂(MoO₄)₃] and Fe₂O₃ proceeded through the formation of intermediate lower oxides, prior to the production of the MO/Fe intermetallic alloys. Based on the intermediate phases that were identified and characterized at the early, intermediate, and final reduction degrees, chemical reaction equations were given to follow up the formation of the MoFe and MoFe₃ intermetallic alloys. The mechanism of the reduction reactions was predicted from the apparent activation energy values (Ea) that were computed at the different reduction degrees. Moreover, mathematical formulations that were derived from the gas–solid reaction model were applied to confirm the reduction mechanisms, which were greatly dependent on the precursor composition and reduction temperature. However, it can be reported that nano-structured MoFe and MoFe₃ intermetallic alloys can be successfully fabricated via a gas–solid reaction technique at lower temperatures. Full article

(This article belongs to the Special Issue Research and Development in the World Foundry Engineering: Materials, Properties and Applications)

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