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Light metals such as aluminum alloys which are being broadly used in automobile sideways, aerospace production as well as segments in military. A light-weight metals prominent for energy consume reduction, efficiency of gasoline and oil increment and superior security to environment. The main utilization of aluminum matrix alloy components have been manufactured by the appropriate behaviors of high tensile strength, hardness, decent machinability, great cast-ability and excessive resistance of corrosion. In the present investigation dealing with casting and heat treatment processes of aluminum alloys 6063 by two different methods such as Sand casting and Die casting. The characterization of AA6063 are analyzed with help of destructive and non-destructive techniques. Finally the results indicates that die casted material gives better results when it is heat treated than the sand casted material.

There are some factors that play a crucial role in deciding the image quality during the optical as well as the micrographic association with the technique of the shadow casting in which contrast of the image has influenced with obliquely depositing of a thin layer of the metal during the process of the microscopic preparations. Further castingadvantages of the using shadow technique are to be observed during the process if shadow casting itself. Shadow casting posses’ number of the advantages over the other casting methods. The most prominent advantage is that if the height and thickness of an object is not completely flat that can be easily notice by the shadow of that object. The lengths of the shadow of the uneven part are so differentiate from other part that can be easily determined. Shadow casting uses the scattering power or even the optical efficiency to bring out the specimens contours and will easily get notice in order to check the flatness of the surfaces.

Evidence comparing the marginal and internal fit of single metal copings fabricated via selective laser sintering and conventional lost-wax casting is inadequate.The purpose of this systematic review was to compare the fit of single metal copings fabricated via selective laser sintering and lost-wax casting. Moreover, the effects of different variables on fit accuracy were determined.Google Scholar, ScienceDirect, SpringerLink, and Wiley databases were searched electronically as well as manually. The mean absolute marginal gap, marginal gap, internal gap, axial gap, and occlusal gap values of single metal copings fabricated via selective laser sintering and lost-wax casting were statistically analyzed to determine and evaluate the factors affecting the fit accuracy (α=.05).Single metal copings fabricated via selective laser sintering had mean absolute marginal gaps and occlusal gaps similar to those of copings fabricated via lost-wax casting, based on a subgroup meta-analysis of gaps evaluated using stereomicroscopy (P.05). The fit of single metal copings was not affected by the type of tooth (P.05). The conventional impression, the indirect digital scan, and the direct digital scan led to similar values of mean axial gap, internal gap, and marginal gap for the copings fabricated via lost-wax casting (P.05). The indirect and direct digital scans led to similar values of mean axial gap, internal gap, and marginal gap for the copings fabricated via selective laser sintering (P.05). Printed wax patterns provided significantly smaller mean axial gap values than milled plastic or milled wax patterns for the copings fabricated via lost-wax casting (P.05). Printed, milled, and conventional wax patterns had similar mean marginal gaps and internal gaps for the copings fabricated via lost-wax casting (P.05). For single copings fabricated via lost-wax casting, Ni-Cr and Co-Cr had similar mean internal gaps (P.05).No statistically significant differences were found between single metal copings fabricated via selective laser sintering and lost-wax casting. Selective laser sintering can satisfy the clinical requirement for single metal copings.

Selective laser melting (SLM) additive manufacturing (AM) technologies provide an alternative to conventional casting and milling procedures in fabricating metal-ceramic dental prostheses. However, the quality of porcelain bond strength to the SLM AM cobalt-chromium (Co-Cr) metal framework of a dental restoration is unclear.The purpose of this systematic review and meta-analysis was to identify in vitro studies that reported the porcelain bond strength to SLM AM Co-Cr dental metal alloys and compare the porcelain bond strength values to cast, milled, and additively manufactured Co-Cr dental alloys.An electronic systematic review was performed in different databases: MEDLINE/PubMed, EMBASE, World of Science, Cochrane, and Scopus. A manual search was also conducted. Studies that reported the porcelain bond strength to SLM Co-Cr metal alloys and in the English language were included. Two investigators evaluated the quality assessment of the studies by applying the JBI critical appraisal checklist for quasi-experimental studies (nonrandomized experimental studies). A third investigator was consulted to resolve lack of consensus. Two subgroups were created based on the test used, 3-point bend and shear bond strength tests. The porcelain bond strength of cast, milled, and AM Co-Cr dental alloys were compared. The I2 statistic and its associated P value were used to assess the heterogeneity between studies. The Eger test was used for determining significance of the funnel pots.A total of 216 studies were collected from the electronic and manual searches. After independently evaluating the titles and abstracts by the reviewers, 26 articles were identified. Three of these were excluded after full-text revision. The porcelain bond strength comparison between the cast and AM alloys for the 3-point bend subgroup revealed a significant result for overall effect (P.001) favoring the SLM method with considerable heterogeneity (I2=83%, P.001). Furthermore, the porcelain bond strength comparison between cast and milled alloys for the shear bond strength subgroup revealed a significant test for overall effect (P=.04) favoring milled procedures with a nonsignificant unimportant heterogeneity (I2= 0%, P.47) and for the 3-point bend subgroup (P.001) favoring milled specimens with a significant considerable heterogeneity (I2=79%, P.001).The metal manufacturing method had no effect on the porcelain bond strength to Co-Cr dental metal alloys.

Aluminium-wood particle composites were formed by casting method. Different weight fractions of wood particle as reinforcement to the Aluminium alloys were used to produce the composites. The physical and mechanical properties such as density, impact strength, tensile strength, hardness and microstructure were investigated. The results showed that the density decreases with the percentage increase in reinforcement. Also, a significant enhancement in the ultimate tensile strength (UTS) of the composite compared to that of pure aluminium was achieved. The maximum UTS of the Aluminium -wood composite is 97.69 MPa and occurred at 20%wt wood particulate addition reinforcement while that of the unreinforced Aluminium is 40.189 MPa. The impact energy varies from 47.00 J to 89.00 J with a maximum value at 10%wt wood particulate addition while the hardness varies from 52.33BHN to 62BHN with a maximum value at 10%wt. All the mechanical behaviours investigated in the study generally showed that the Aluminium -wood composite exhibited better mechanical properties than the pure Aluminium. The microstructure examination revealed that the wood particles were uniformly distributed in the metal matrix composite.

Exploiting Bilevel Optimization Techniques to Disconnect Graphs into Small Components In order to limit the spread of possible viral attacks in a communication or social network, it is necessary to identify critical nodes, the protection of which disconnects the remaining unprotected graph into a bounded number of shores (subsets of vertices) of limited cardinality. In the article “'Casting Light on the Hidden Bilevel Combinatorial Structure of the Capacitated Vertex Separator Problem”, Furini, Ljubic, Malaguti, and Paronuzzi provide a new bilevel interpretation of the associated capacitated vertex separator problem and model it as a two-player Stackelberg game in which the leader interdicts (protects) the vertices, and the follower solves a combinatorial optimization problem on the resulting graph. Thanks to this bilevel interpretation, the authors derive different families of strengthening inequalities and show that they can be separated in polynomial time. The ideas exploited in their framework can also be extended to other vertex/edge deletion/insertion problems or graph partitioning problems by modeling them as two-player Stackelberg games to be solved through bilevel optimization.

The 3D visualization of the porosity in high-pressure die casting (HPDC) Mg alloys AZ91D and Mg4Ce2Al0.5Mn (EA42) was investigated by X-ray computed tomography. It was demonstrated that the volumetric porosity at the near-gate location for alloy EA42 was significantly higher than that far from the gate location. This difference resulted from the low valid time during intensified casting pressure conditions. Specimens of alloy EA42 exhibited a narrow pore distribution in the side view (∼0.5 mm) compared to the wide distribution (∼1.8 mm) of alloy AZ91D, which was mainly attributed to the formation mechanism of the defect band. The formation of microporosity in the defect band of alloy EA42 was inhibited because of the significant latent heat released by a large amount of the Al11Ce3 phase segregated in the defect band during solidification. Additionally, an effective estimator (Z-Propagation) was introduced, which is proposed to predict the projected area fraction of the porosity (f) involved during tensile failure with better effectiveness compared with traditional methods based on the actual fractured surface. By coupling the Z-Propagation method with the critical local strain model, the logarithmic fracture strain and true fracture stress of the specimens were predicted within 3.03% and 1.65% of the absolute value of the average relative error (AARE), respectively.

Strength and ductility synergy in an Mg-3mass%Al-Mn (AM30) alloy sheet was successfully improved via twin-roll casting and annealing at low-temperature. An AM30 alloy sheet produced by twin-roll casting, homogenization, hot-rolling, and subsequent annealing at 170 °C for 64 h exhibits a good 0.2% proof stress of 170 MPa and a large elongation to failure of 33.1% along the rolling direction. The sheet also shows in-plane isotropic tensile properties, and the 0.2% proof stress and elongation to failure along the transverse direction are 176 MPa and 35.5%, respectively. Though the sheet produced by direct-chill casting also shows moderate strengths if the annealing condition is same, the direct-chill casting leads to the deteriorated elongation to failure of 23.9% and 30.0% for the rolling and transverse directions, respectively. As well as such excellent tensile properties, a high room-temperature stretch formability with an Index Erichsen value of 8.3 mm could be obtained in the twin-roll cast sheet annealed at 170 °C for 64 h. The annealing at a higher temperature further improves the stretch formability; however, this results in the decrease of the tensile properties. Microstructure characterization reveals that the excellent combination of strengths, ductility, and stretch formability in the twin-roll cast sheet annealed at the low-temperature annealing is mainly attributed to the uniform recrystallized microstructure, fine grain size, and circular distribution of (0001) poles away from the normal direction of the sheet.

Metal matrix syntactic foams (MMSFs) are advance hybrid materials which reflect synergetic combination of particle reinforced composites and close cell metal foams. Recently, MMSFs have become considerably popular for several industrial areas because of their low density, high compression strength, good ductility and perfect energy absorption ability. In this paper, Al 7075/bubble alumina syntactic foams were fabricated by recyclable pressure infiltration casting method. Macroscopic and microscopic investigations showed that almost flawless infiltration was obtained between 2 – 4 mm hollow bubble alumina spheres and total porosity values of fabricated foams varied between % 43.2 and % 45.6. As for mechanical analyses, all foam samples were subjected to quasi-static compression test (1 mm/min deformation rate) and their crucial properties such as compression strength, plateau strength, densification strain and energy absorption capacity were determined. Besides, aging heat treatment (T6) was applied to certain samples in order to explore probable effects of heat treatment on the mechanical responses. The outcomes indicated that there was a positive relationship between the aging treatment and compressive features. Under the compressive loading, even though T6 treated foams showed a tendency to brittle fracture, their as-cast variants exhibited ductile behavior.

It is of great importance to further investigate grain selection mechanism for the production of single crystal (SX) turbine blade because a single crystal with optimized crystal orientation will enhance service performance of the blade severely. In this paper, single crystals with different deviation angles, i.e. 6°, 12° and 29°, were obtained using directional solidification under the same casting conditions. It has been found that the grain selection in spiral selector is a coupling process where high order dendrites branch in the front side and primary dendrites disappear in the back side based on the metallographic analysis and electron back scatter diffraction (EBSD). Considering the development of liquid/solid interface by numerical simulation, a combination effect with space expansion, geometrical restriction and grain competition was proposed for spiral grain selection. The space expansion mechanism dominates the process as it provides growth space and driving force for high order dendrites advancing. Thereby, the smaller the take-off angle (θ) is, the larger space and the stronger driving force high order dendrites will get, and the higher efficient the selector will be. The competitive growth between the secondary dendrites plays more contribution than that of primary dendrites, i.e. grain with preferred secondary dendrites instead of preferred primary dendrites could outcompete during grain selection, and this is the reason why spiral grain selector cannot optimize the orientation of the primary dendrites. These findings provide experimental evidence for spatial control of SX growth, and benefit the sophistic casting fields such as turbine blade casting for improved yield.

Industrial technology has been developed for the semi-continuous casting of large-sized ingots from deformable aluminum alloys through the use of complex modeling, including computer modeling and physical modeling. The ProCAST and ANSYS software packages equipped with the FLUENT module were used for computer modeling. The physical modeling was carried out on a laboratory semi-continuous casting unit (SCCU), which represents a tenfold reduced physical model of an industrial casting unit for the vertical semi-continuous casting of ingots from aluminum alloys. An aluminum-magnesium alloy with the addition of 0.05% (wt.) of scandium was used as the object of modeling. The results of computer modeling were tested at the SCCU, and then computer modeling was carried out for casting a large ingot. According to the modes obtained in the simulation, an ingot with a section of 1310×560 mm was cast under industrial conditions, which had a good surface quality with the absence of casting defects. In the microstructure of an industrial ingot and an ingot cast on the SCCU, there were no primary intermetallic compounds Al3(Sc, Zr), which makes it possible to strengthen the alloy upon annealing. To check the manufacturability during rolling, billets with a size of 40×120×170 mm were cut from these ingots, which were hot-rolled to a thickness of 5 mm, and then cold rolled to a thickness of 1 mm. The rolling results revealed good workability of the alloy, which was reflected in the high quality of the surface and the absence of cracks at the edges of the rolled stock. The mechanical properties of sheets obtained from both ingots were at the same level, which proves the reliability of casting modes for ingots obtained by complex modeling and the validity of their use for industrial conditions of the semi-continuous casting of large ingots from aluminum alloys.

In recent decade’s machine tools and cutting tool technology, (EDM) is utmost trending techniques for making factual shape on different material like HSLA, H11, H-13 etc. steels and is maximum endorsed techniques to be ensure for mold & die making. In Electric discharge machining process increases the mechanical and physical properties when used with powder suspension and with assertive composite of electrode materials. Result analysis through the effect of parameters and their level of practically examined least number of experiments trail by during slot cutting by using Taguchi technique identified tool wear. Now a day’s most prominent materials which are largely used in die making & mold casting industries like HSLA, H11 die steel. In the latent research M.R.R and T.W.R examined through the result analysis by the taugchi techniques changes in the level of the selected parameters. Selected parameters like electric current, pulses-on time, graphite and tungsten powders imposed in dielectric by changes the range of different levels with or with-out using magnetic fields. To find out the better result of analysis we followed the ANOVA techniques to optimize and the effects of the parameters at optimum level/range for the M.R.R and T.W.R of the cooper tool.

The property evaluation of Aluminum alloys a quite a challenging task and is an essential one to achieve improved mechanical and metallurgical properties during casting. This paves the way for the present research, in which the casting of commercial A356 and A319 Al alloys have been performed under stationary and vibratory state. The vibrational recurrence has been varied between 0 Hz and 400 Hz with a constant amplitude of 15 μm during casting. Thereafter, the quality of both casted materials has been evaluated by measuring their yield strength, ultimate tensile strength and % elongation. Experimental results revealed that the higher intensity of oscillation improves mechanical properties with the reduced grain size of α-Al. It has been also observed that the fraction of nucleation sites is increased due to the vibration.

Combined stir casting and squeeze casting processes were used to fabricate Al5083 matrix composites reinforced with 20, 25, and 30 wt% SiCp. The microstructure, mechanical properties and wear behavior of the composites fabricated by combined stir casting and squeeze casting were compared with those fabricated by stir casting. The results revealed that the combined casting method improved the distribution of SiC particles through the reduction of the agglomeration of SiC particle and reduced the porosities of the samples from 2.32% to 1.29% in the sample containing 30 wt% SiC. These modifications led to the enhancement of mechanical properties i.e. increased the hardness to 85 BHN and the compressive strength to 350 MPa for the sample containing 30 wt% SiC fabricated by the combined casting method. In addition, the wear resistance of the samples fabricated by the combined casting method improved because of the reduced size of the wear debris as well as the smaller worn region. The dominant wear mechanism of all the composite samples fabricated by both methods was the delamination of the tribological layer while adhesion wear was dominant in the monolithic Al alloy.

Brass has an interesting set of characteristics, such as good wear capabilities and high electrical and thermal conductivity. Aluminium has been utilized as reinforcement and matrix in the development of advanced composites. In the present investigation, the new unique material the brass/Al composite has been developed by liquid casting route. The effect of Al filler in varying wt.% on the mechanical properties of new brass/Al composites were investigated. The tensile strength and hardness were evaluated for produced composites. The microstructural features were observed by optical microscopy. The optical microscopy revealed the uniform distribution of Al particles in the brass matrix. The tensile strength and hardness increased by increasing the Al contents. It was interestingly observed that the addition of 4 wt% Al exhibits the uniform distribution of irregular block shape strengthening phase and has the best mechanical properties. The fine surface was obtained by addition of Al. This research work provides an advanced strategy for improving the overall characteristics of existing brass.

The construction industry being a major sector that contributes greatly for economic growth of the country and also created adverse effects on the environment. This has encouraged the development of sustainable materials through research in recent times. Furthermore, construction of building majorly get delayed due to hand compaction or vibrating of concrete during casting, considering all this factors in this study research was carried out on developing Self-Compacting Geopolymer Concrete (SCGC) with use of various industrial byproducts such as Flyash, Ground Granulated Blast Furnace Slag (GGBFS) and Alccofine in varying binder percentage of 80:10:10, 65:20:15, 50:25:25. The results showed highest mechanical strength and durability characteristics for 65:20:15 binder ratio.

Particle reinforcement has been considered as the new technological advancement in terms of fabricating metal matrix composites (MMCs). There are different kinds of techniques that have been historically used to produce MMCs and casting has been the most used technique. However, recent developments have identified friction stir processing (FSP) as the most preferred technique over casting due to its outstanding benefits. This paper reports on the status of utilizing the FSP technique to produce automotive-based aluminium metal matrix composites (AAMMCs) for the past ten years. The influence of the reinforcements on the mechanical properties of different AAMMCs has also been highlighted. The identification of gaps to give future direction has also been discussed in this paper.

It has become known that copper alloys are commonly used in heat exchangers and other marine industries. Although copper-nickel alloys have better properties than copper-zinc alloys in general, they are very expensive. The current research aims to give the alloy to give brass alloy (the cheapest alloy) superior properties in order to improve its performance and prolong the life of its use in the most important parts of the heat exchangers (pipes). Casting and heat treatment elements were used, and casting was carried out in a manner that ensures that the grains were softened to improve the properties. Tests were conducted to evaluate the performance of alloys such as hardness, oxidation and thermal shock. The effect of temperature and thickness of the oxide layer on the oxidation behavior was also studied. The results showed a significant increase in the thermal shock resistance, a positive change in the oxidation behavior, in addition to a significant improvement in the plasticity and adhesion of the oxide layer.

The metal casting process is one of the industry's most significant production processes and is also one of the eco-friendly techniques for making usable parts. Metal smelts are the main melting process that takes several stages. However, concerning increased energy consumption, longer casting periods, and major failures, the conventional casting process does have significant problems. New methods are being developed to address these deficiencies of classic casting procedures. The technique of microwave casting is one of the innovative methods that satisfy current needs in the business. The process involves complexity of understanding the heating rate, material interaction phenomenon etc. A 3-D model of the in situ casting process was generated through COMSOL multiphysics software tool. A complete simulation based studies were carried out to predict the thermal history of the metal melting. The simulation results obtained by considering various power levels (1500 W to 3500 W) to predict melting time, average heating rate, desired energy to melt the materials. It was observed that the role of electric field distribution inside the microwave applicator and distribution of the temperature in the charge play a important role at hot spot condition and also to increase in temperature in the charge. It is noted that energy decreases are 15.37% at 3500 W, 9.8% at 2000 W, 16.67% at 2500 W, and 13.6% at 3000 W. Finally, the simulation data showed that the heating of the bulk metal is rapid and consistent at specific location of the mold assembly.

This study proposed the methodology to produce silicon carbide particulate MMCs based on aluminum to create typical low-cost MMCs and achieve a homogeneous scattering of ceramic material. The trial was done with a different weight fraction of Silicon Carbide (2%, 3%) and Tungsten Carbide (2%, 3%) with all other parameters being maintained. A growing hardness was noticed with the rise in SiC & WC weight 2 to 3%. The advantages of this technique include improved mechanical characteristics, minimal residual stress and deformation, and fewer flaws. Although casting technique poses numerous technical obstacles, this problem can nevertheless be addressed. Aluminum materials with high strength to weight and low density have been proven to be the best option. As lightweight materials are developed, weight reduction has been offered several alternatives through conducting different tests to analyze different features such as mechanical and metallurgical characteristics.

This Investigation provides an insight of fabrication Aluminium alloy 2025 T6 metal matrix composite reinforced with Red Mud using stir casting methodology. % of reinforcement along with grain size and stirrer blade angle are considered as control factor which are used for the fabrication of orthogonal trail design of Taguchi philosophy. Mechanical characterization like tensile strength and micro hardness were considered as output responses. Recently formulated Lichtenberg Optimization Algorithm and Whale optimization Algorithm were utilized for obtaining optimized control factor. According to ANOVA outcome, blade angle and grain size are the most significant factor for maximization of tensile strength and micro-hardness respectively. Also, confirmatory results shown that Lichtenberg optimization algorithm has provided more precise prediction which can be helpful for casting of Aluminium alloy 2025 T6 metal matrix composite reinforced with Red Mud.

Process of horizontal twin roll casting magnesium alloy was analyzed by numerical simulation. Taking solidification welding line in cast rolling area as research object, the characteristic change of solidification welding line caused by casting rolling temperature, casting rolling speed, and roll heat transfer capacity and its influence on the forming process of casting rolling area were analyzed. The results show that increasing casting temperature, casting speed or reducing heat transfer capacity of roll can make solidification welding line shift to exit of casting rolling zone. Increasing casting temperature and casting speed will increase difference between middle and edge of the solidification welding line along casting direction and heat distribution of whole slab is more uniform. However, effect of improving heat transfer capacity of roll is completely opposite. According to this, optimum process parameters of casting and rolling magnesium alloy with plate thickness of 6 mm are put forward to reduce probability of edge crack.

Accurate segmentation of casting defects plays a positive role in the quality control of casting products, and is of great significance for accurate extraction of the mechanical properties of defects in the casting solidification process. However, as the shape of casting defects is complex and irregular, it is challenging to segment casting defects by existing segmentation methods. To address this, a spectrum domain instance segmentation model (SISN) is proposed for segmenting five types of casting defects with complex shapes accurately. The five defects are inclusion, shrinkage, hot tearing, cold tearing and micro pore. The proposed model consists of three sub-models: the spectrum domain region proposal model (SRPN), spectrum domain region of interest alignment model (SRoIAlign) and spectrum domain instance generation model (SIGN). SRPN uses a multi-scale anchoring mechanism to detect defects of various sizes, where the SSReLU and SCPool functions are used to solve the spectrum domain gradient explosion problem and the spectrum domain over-fitting problem. SRoIAlign uses the floating-point quantization operation and the tri-linear interpolation method to quantize the 3D proposals to the feature values in an accurate manner. SIGN is a full-spectrum domain neural network applied to 3D proposals, generating a segmentation instance of defects in a point-wise manner. In the experiments, we test the effectiveness of the proposed model from three aspects: segmentation accuracy, time performance and mechanical property extraction accuracy.

The prediction of M-shaped δ-ferrite content along the thickness direction of continuously cast 304 austenitic stainless steel slab was performed using a diffusion-controlled phase transformation module of Thermo-Calc software. The surface and center of the slab, which solidified with different cooling rates and secondary dendrite arm spacing, were used for kinetic calculations. Comparison between observations and calculations for slab specimens demonstrated that the moving-boundary model could predict retained δ-ferrite content according to various thermal histories. After this validation, the effects of different cooling rates at liquid and solid-state were analyzed to understand the importance of each stage on the diffusion-controlled δ $$\to \gamma$$ phase transformation. Decrease in solid-state cooling rate generally had a larger effect on the reduction of δ-ferrite during cooling when the solidification rate was fast (27.75 °C/s) than when it was slow (0.075 °C/s). This model can be used to predict and control δ-ferrite behavior under different thermal histories during slab casting and welding practices.

Teachers with so-called migration backgrounds are often assumed to possess higher intercultural competencies or skills for more adequately dealing with migration-related diversity than other teachers. However, these assumptions of higher intercultural competencies, specific pedagogical orientations and attitudes have rarely been systematically empirically examined. On the other hand, such a utilitarian ethnicization is increasingly criticized by migration researchers in educational science in Germany as furthering stigmatization and deprofessionalization. Against this background, our paper aims to contribute to the lively discourse about teacher with so-called migration backgrounds. We start with analysing teacher data from the German National Education Panel Study (NEPS). Our analyses indicate that teachers with and without so-called migration backgrounds do not differ significantly in most respects. These findings led us to methodological considerations with regard to the (non-)usefulness of the statistical category of ‘migration background’ in educational migration research.

Foam concrete is widely used in wall construction due to its high thermal and acoustic insulation, hence reducing energy consumption and CO2 emission. Meanwhile, the palm oil industry results in an enormous number of by-products in forms of fibre, shell, ash and clinker. About 12 million tonnes of palm oil fuel ash (POFA) are produced annually and regularly disposed in landfills causing several environmental, economic and health adverse consequences. The purpose of this research is to investigate the performance of different types of lightweight load-bearing panels under axial loading and the effect of using POFA as a sand replacement on the behaviour of the panels. A total of 16 panels were tested and compared in terms of bearing capacity and cost efficiency using four-panel types, namely normal, reinforced, fibreglass confined and infilled steel sheet panels. Two mixtures were used in panels casting: 0% and 40% POFA. The results showed that using POFA increased the capacity and slightly increased the ductility of the panels. Among the different panel types, the use of fibreglass mesh resulted in the highest axial capacity and ductility. However, reinforced and filled steel panels showed better brittleness and established a slight increase in the capacity compared to the normal panels. In addition, fibreglass confined panels are more cost-efficient compared with the reinforced and infilled panels. In conclusion, fibreglass confined panels demonstrated the best performance, and the use of POFA as a sand replacement significantly improves foam concrete strength.

As important lifting and transporting machines in the metallurgical industry, casting cranes are much dangerous because the cargos they lift are high-temperature metal solutions. The ladle has a swing in the trolley moving process caused by the flexible characteristic of the wire rope, which may cause a splash of the metal solution and a collision of the metal ladle with other objects. There are many casualties caused by ladle sloshing and collision accidents every year, so the anti-sway control of the crane has gradually become an important engineering problem. In this paper, a dynamic model of the casting crane is established and a sliding mode controller based on RBF neural network (NNSMC) is designed. The NNSMC greatly reduces the complexity of the control equations and only needs to utilize the position and velocity of the trolley as feedback signals to realize the closed-loop control. The stability and robustness of the proposed controller are proved by Lyapunov theory and Barbalat’s Lemma. The simulation results show that the controller has an excellent control performance and can suppress the ladle sloshing in a short time, which ensures the safety and efficient operation of the casting crane.

An important part of nursing care is the physiotherapist’s physical exercise recovery training (for instance, walking), which is aimed at restoring athletic ability, known as rehabilitation (rehab). In rehab, the big problem is that it is difficult to maintain motivation. Therapies using robots have been proposed, such as animalistic robots that have positive psychological, physiological, and social effects on the patient. These also have an important effect in reducing the on-site human workload. However, the problem with these robots is that they do not actually understand what emotions the user is currently feeling. Some studies have been successful in estimating a person’s emotions. As for non-cognitive approaches, there is an emotional estimation of non-verbal information. In this study, we focus on the characteristics of real-time sensing of emotion through heart rates – unconsciously evaluating what a person experiences – and applying it to select the appropriate turn of phrase by a voice-casting robot. We developed a robot to achieve this purpose. As a result, we were able to confirm the effectiveness of a real-time emotion-sensitive voice-casting robot that performs supportive actions significantly different from non-voice casting robots.

A twin-wheel caster for casting thin aluminum alloy wire was designed, assembled, and tested. Molten metal was ejected from the nozzle (cross-sectional area: 4 mm2) of a crucible into a triangular groove that was machined on the outer surface of the lower wheel. The metal was solidified by the upper and lower wheels. Wire made of Al-1.2%Fe or 6061 aluminum alloy, whose cross-sectional area was smaller than 20 mm2, could be cast at a speed of 6 or 7 m/min. The upper and lower wheels were made of copper to increase the cooling rate. The diameter of the upper and lower wheels was 200 and 600 mm, respectively. The thickness of the wheels was 10 mm.

The development of modern high-tech industries of industrial production is impossible without the development of new methods for processing materials with high mechanical characteristics. There is a growing need for an increase in the proportion of parts made of aluminum alloys, a more complex configuration of cast parts, an increase in their reliability and durability in operation, etc. All this poses for metallurgists and foundry workers the task of creating new technologies for producing alloys, improving the technical and economic characteristics of structural materials, improving the quality and reducing the cost of castings.Hypoeutectic silumins have good casting properties, good weldability, machinability and corrosion resistance. However, they are prone to the formation of a coarse needle-like state, which reduces their useful characteristics. To eliminate this phenomenon, it is necessary to apply special technologies and the most common is their modification, which provides grain refinement. This makes it possible to use silumins for the manufacture of castings of complex shapes with increased density and low shrinkage porosity. Such parts can withstand average loads in critical units. Aluminum-silicon alloy AK7 or (ASi7Mg0.3) is a typical silumin, which is in demand in the automotive industry, construction, aircraft construction, machine, automobile and tractor production. It is appreciated for its good casting properties, weldability, machinability and corrosion resistance.

Al-Si casting alloys are the most commonly used materials for piston alloys. The coefficient of thermal expansion is the key property of a piston material for improving the overall performance and service life of an engine. In the present study, the relationship between the morphology of the excess silicon phase and the coefficient of thermal expansion of Al-Si binary casting alloys was discussed. Optical and scanning electron microscopy were utilized to observe the morphology of the excess silicon phase in the Al-Si binary casting alloys before and after solution aging treatment. The results showed that the morphology of the excess silicon phase significantly influenced the coefficient of thermal expansion of the Al-Si binary casting alloys. After solution aging treatment, the coefficient of thermal expansion of the Al-Si binary casting alloys increased due to the rounding and granulating of the excess silicon phase precipitated during the casting process and decreased due to the precipitation of the finely dispersed Si phase in the α-Al matrix. The change in the coefficient of thermal expansion depended on which of the two kinds of morphological transformation of the excess silicon phase is dominant.

The structure of the AA5056-Al3Er composite and the initial alloy was studied by optical and scanning electron microscopy. The introduction of 0.23 wt.% particles does not modify the structure of the aluminum alloy, but, due to dispersion hardening, increases the ultimate tensile strength and ductility of the metal matrix. Rolling the AA5056-Al3Er alloy leads to a more uniform distribution of particles in the volume of the material, but does not increase its yield strength or ultimate tensile strength. A more uniform distribution of deformation due to the influence of Al3Er particles made it possible to increase the ductility of the AA5056 alloy.

Introduction Transparent, patient-specific vocal tract replicas are helpful in research and educational endeavors but challenging to procure. An accessible method for fabricating these models, improving on previously suggested processes, would make them more widely available. Method Detailed instructions for fabricating a transparent, patient-specific vocal tract model were addressed. The broad steps were (1) digitally reconstructing (patient-specific) vocal tract geometry, (2) producing a vocal tract mold (using methods such as three-dimensional [3D] printing), and (3) casting transparent material (such as silicone) around the vocal tract mold and removing the mold. The cavities remaining within the cast represented the exact geometry of the vocal tract. Discussion A combination of 3D printing and silicone casting can produce useful vocal tract replicas. Several simple changes to previous methods can improve consistency and reduce the labor and cost of production. Limitations and potential modifications to expand the applications of this method are discussed.

A tundish is a device from which liquid steel is pour into a mold. Therefore tundish hydrodynamic conditions have a significant impact on solidification during continuous steel casting (CSC) process. Modification of ladle shroud workspace, allows for the modification of liquid steel movement in the tundish. In the following work, numerical simulations were performed which allowed the impact of the modification of the ladle shroud workspace on the liquid steel flow structure in a one-strand tundish to be determined. In order to assess the impact of the modification of the ladle shroud on the behavior of the liquid steel in the tundish, simulations were performed, on the basis of which the percentage share of stagnant, ideal mixing and plug flow zones were determined. In addition, the mixing parameters were determined, allowing the estimation of casting duration during sequential casting. The flow fields of liquid steel for each modification of the ladle shroud were performed. The average velocity of liquid steel flowing through the tundish, the Reynolds number and turbulent intensity were also described. The obtained results showed, among others, that the application of three cylinders with a diameter of 0.041 m into the ladle shroud with a diameter of 0.11 m increases the share of active flow in the tundish in relation to the tundish with Conventional Ladle Shroud. At the same time, applying a ladle shroud with a diameter of 0.11 m during casting is the most favorable in relation to the hydrodynamics of the tundish.

Background: In the conservative management of distal radial fractures (DRFs), the optimal dorsi-volar angulation of the wrist at cast immobilization and proper cast molding to minimize the risk of redisplacement are unclear. This study identified the predictors of fracture redisplacement during cast immobilization for adult DRFs. Methods: We examined for dorsi-volar angulation, gap index, volar tilt (VT), radial inclination (RI), and radial length (RL) in lateral or posteroanterior radiographs of 90 DRFs. We investigated possible predisposition factors for redisplacement including patient age, sex, extra- or intra-articular fracture, metaphyseal comminution, original displacements, dorsi-volar angulation of the wrist at cast immobilization, restoration of the volar cortex at cast immobilization, and gap index of the cast. Results: Neither dorsi-volar angulation nor gap index had significant association with an unacceptable alignment nor decrease of VT, RI, and RL. In multivariate analysis, patient age, original displacement, and intra-articular fracture were the significant predictors of an unacceptable alignment or decrease of VT and RI. Conclusions: Our findings indicate dorsi-volar angulation and cast molding quality have no clinical effect on preventing fracture redisplacement. The predictive factors of the displacement were patient age, original displacement, and intra-articular fracture.

The objective of this work is to propose an advanced automated damage detection and damage reconstruction algorithm for damaged gear tooth repair. It can automate tool path design and provide precise repair volume detection for complex repair volume. First, models of the damaged and nominal parts were obtained by reverse engineering. Next, the damaged model was aligned with the nominal model. After that, both models were sliced into layers, and a set of parallel and equidistant casting rays was used to intersect with these layers to extract the repair volume. Then the repair tool path was generated and used to guide the laser additive manufacturing process for repair. The corresponding repair experiment and validated numerical model based on repairing a complex gear fracture was conducted to evaluate the reconstruction algorithm efficiency and repair part quality. Microstructure analysis and Vickers hardness test were carried out to evaluate the repaired part quality. The coincidence of scanning points between repaired model and the nominal model is high. The repair experiment confirmed the strong efficiency of this repair algorithm for complex geometry repair. A 3D finite element model was also developed to simulate the repair process and provide critical deformation and residual stress of the repaired parts. The predicted temperature and residual stress results were compared and showed a good agreement with the experimental measurements. These results further validated that the proposed repair algorithm and simulation model are suitable and efficient for the automated repair of damaged components.

Microsegregation is an important phenomenon occurring during solidification, with potentially detrimental effects such as formation of brittle intermetallics at the later stages of solidification, hence leading to degraded mechanical properties and workability of cast products. Grain refinement is a well-established treatment in casting plants to achieve cast structures with fine equiaxed grains and enhance chemical homogeneity. Although both subjects have been deeply studied over the past decades, there are few reports dealing with the link between grain refinement and microsegregation. The present work aims to address this problem through spatially resolved simulation of microstructure evolution during solidification of a model binary system. The simulations show how increasing the number density of inoculant particles results not only in the reduction of the average grain size, but also in a change of morphology from dendritic to globular. The combination of these two effects results in a complex trend, manifested by a non-monotonic correlation between the level of microsegregation and the number density of the inoculants. This means that, in contrast to the predictions of the commonly used Scheil model, there can be a specific number density of seeds for which microsegregation is at the highest level. The simulation results are shown to be consistent with the experiments on Al-2.1 at. pct Cu alloy and discussed in view of the relevant physical factors and industrial implications.

During continuous casting of steel billets, mould lubrication is provided by addition of oil in case of open casting and mould powder is used during close casting. Open casting of steel billets has hazards like mould spitting of liquid metal whereas in case of close casting the sequence length is less incurring more refractory consumption. To get combined advantages of both, a new class of lubricant has been developed by dispersing mould powder in oil using nonionic dispersants. The characteristics of this suspension are studied extensively to evaluate all required properties for plant operation. The result of plant studies shows, (1) reduction in liquid metal spitting by 60% and thence reducing hanger breakout, (2) heat extraction in the mould is reduced by 14% and (3) no entrapment of mould powder found in the billet. This can be used as an alternative to close casting and hence increasing sequence length.

The tensile strength, hardness and toughness of any materials are the most important mechanical properties in the selection of materials for varied industrial applications. In the development of aluminum based composite material, tensile strength and hardness were significantly improved by adding various ceramic reinforcement particles. However, toughness was reduced. In this research work, an attempt was made to enhance tensile strength, hardness and toughness simultaneously by using carbonized eggshell as reinforcement material developed via electromagnetic stir casting. The process parameters used in this study are the matrix pouring temperature, wt.-% of the reinforcement; preheat temperature, stirring current and stirring time. Response surface methodology (RSM) is used for conducting the experiment. The multi-objective optimization technique utility theory is employed to optimize the combined mechanical properties viz. tensile strength, hardness and toughness. Microstructure results show that at the optimum level of process parameters, eggshells are uniformly distributed. Confirmation tests are conducted to validate the experimental results. Experimental results revealed that at optimum process parameters, hardness and tensile strength are significantly improved without affecting the toughness property of the composite. The optimum level of process parameters to enhance all mechanical properties (tensile strength, hardness and toughness) were found to be a reinforced preheating temperature of about 448.32 °C, a stirring current of about 11.64 A, a stirring time of about 63.64 s, a maximum pouring temperature of about 800.24 °C and a percentage of eggshells of about 9.16 %. The novelty of this work lies in the fact that no attempt was made to optimize these electromagnetic process parameters. Corrosion loss, thermal expansion behavior and a wear test were investigated to observe the effect of adding eggshell at optimum electromagnetic stir casting parameters.