Cast Plates Research Articles

Research into the Structure and Adhesion of WCCoCr Coatings Plasma-Sprayed onto Castings of AlSi Alloy Plates

The article presents structural investigations and mechanical properties of hard coatings deposited by spraying WCCoCr powder in an argon-hydrogen plasma jet onto the surfaces of AlSi10Mg alloy casting plates. Two variants (A and B) of processing parameters of the powder spraying process onto the surface of silumin plates were applied, resulting in different coating thickness. The coating applied according to variant A was done with 12 passes, and its thickness was approximately 150 μm. The coating applied according to variant B was done with 20 passes, and its thickness was about 320 μm. The microstructures of these coatings are similar, consisting of wavy, alternately deposited phases of solid solutions with varying concentrations of elements, and fine spherical phases, irregularly dispersed carbides. A qualitative analysis of the distribution of microstructure components was performed based on surface mapping. Precipitates differing in their degree of grayness and shape were identified based on microanalysis of their chemical composition. The porosity assessment of coatings performed in five randomly selected areas amounts to an average of 9%. The applied coatings exhibit good adhesion to the substrate, as evidenced by the absence of delamination during scratching tests using a diamond Rockwell indenter loaded with a force of 10 N. The coating hardness averaged 1180HV0.2. The test results indicate the high quality of the WCCoCr coatings, regardless of their thickness.

Effect of APMImBr ionic liquid on the migration of silver in copper electrorefining

As the grade of copper concentrate decreases and its composition becomes increasingly complex, the silver content in the anode plate casting after fire refining increases. This leads to a high silver content in the copper cathode during electrorefining and a substantial loss of precious metals. This study investigated the effect of 1-aminopropyl-3-methylimidazolium bromide (APMImBr) ionic liquid on the migration of silver during high-silver anode plate electrorefining. The results show that APMImBr is adsorbed on the anode surface by reacting with Ag+ released from the anode to form AgBr precipitates, thereby preventing Ag+ ions from entering the electrolyte. Simultaneously, agglomerates of fine Ag–Se compounds and AgBr particles form, resulting in anode slime particles that are sufficiently large to settle quickly to the bottom of the cell, thus inhibiting fine silver-containing particles from adhering to the cathode. Furthermore, APMImBr adsorbs onto the cathode surface, forming CuBr intermediates and inhibiting Cu2+ electrodeposition. This facilitates the refinement of the surface grains and flattens the copper cathode surface. The Ag content of the cathode decreased continuously as the concentration of APMImBr increased. The Ag content of the cathode decreased by 41.67% from 6.0 ppm (no additives) to 3.5 ppm upon the addition of the optimal concentration of 300 mg/L of APMImBr.

Compound Castings for the Coke Industry.

In this paper, issues related to the technology of compound castings composed of two parts, i.e., the working layer and the supporting part, made of X46Cr13 high-chromium steel and EN-GJL-HB 255 grey cast iron, respectively, in a liquid-solid system by pre-installing a monolithic insert in the mould cavity are presented. As a part of the research, the mechanism of formation of transitional zones in the bonding area of the above-mentioned two alloys was identified and described. It was shown that the phenomenon that determines the formation of a permanent bond between the joined materials is the transport of C and heat from the "high-carbon and hot" material of the supporting part poured into the mould in the form of liquid cast iron to the "low-carbon and cold" material of the working layer placed in the form of a steel monolithic insert inside the mould cavity. In the paper, the suitability of the compound castings technology developed for use in the coke industry is also presented. Full-size high-chromium steel-grey cast iron compound casting plates designed for the coke quenching car lining were positively verified in real coke plant operating conditions.

Design and Development of LM24 plate Casting using Solid Cast Simulation Technique

Abstract: This research deals with the elimination of defects in aluminium alloy castings and enhancement in the casting yield and quality. The main intention of the work is to improve the quality of a cast component using Computer Aided Casting Simulation Software. SOLID Cast simulation software is used for simulating the solidification process of casting and visualizing outputs showing possible problematic areas or defects which may occur in the cast product. Plate Castings of aluminium alloy - LM 24 are produced with different designs of gating systems and tested for defects like porosity using Archimedes immersion Technique and also Radiographic testing is used to check the quality of the castings. The produced castings are observed to be sound, and the results obtained are in agreement with the simulation results. Hence it is verified that solidification simulation helps in improving the quality of castings without any shop-floor trails. Casting yield and percentage porosity values are determined for 12 castings produced with different gating systems. The best results are observed to be produced by the castings having a 1-Ingate system in horizontal or lateral positions.

Analysis of labor productivity in reinforced concrete structures using time study methods

The source of the success of a project in fulfilling the three aspects namely cost, quality, and time from one of the existing resources is the productivity of its workforce. The time study method is the right method used to determine the standard time of a job. The average value of productivity on column formwork is 10.65 m2/OH, beam formwork is 46.89 m2/OH, and plate formwork is 73.29 m2/OH. Column reinforcement work 204.51 kg/OH, beam reinforcement work 349.93 kg/OH, plate reinforcement work 287.57 kg/OH. Column casting work 7.96 m3/OH, beam casting work 25.31 m3/OH, plate casting work 15.81 m3/OH. Several factors greatly affect labor productivity. Comparison of the work productivity of reinforced concrete structures in the Ubud Market project based on the calculation results obtained the average productivity coefficient in the field of labor.

Locking plate versus K-wires and cast fixation in lateral closing-wedge osteotomy for cubitus varus deformity.

The aim of this study was to assess the clinical and radiographic outcomes of cubitus varus treatments based on different fixation methods: Locking plate vs. Kirschner-wires (K-wires) and cast fixation. This retrospective study of 28 patients was performed in lateral-wedge osteotomy for cubitus varus deformity in our hospital from July 2018 to July 2020. 14 patients in group A were treated by locking plate after lateral closing-wedge osteotomy, whereas other 14 patients were treated by K-wires in group B. We measured the bony union and carrying angle. The clinical and radiographic outcomes were assessed according to the Bellemore criteria. No nonunion, neurovascular injury or myositis ossificans was noted at follow-up. In group A, 1 patient with lateral condylar prominence was found. In group B, 2 patients with pinning site infection were treated successfully with oral antibiotics and 2 patients needed revision surgery for residual varus. According to the Bellemore criteria, statistically significant difference was noted between the two groups (P = 0.0458). In the present study, no statistically significant difference was noted in the length of incision and operation time between the 2 groups (P > 0.05). However, the postoperative carrying angle was significantly different at final follow-up between the 2 groups (P < 0.01). Compared with K-wires and cast fixation, we recommend the wedge osteotomy with lateral locking plate to treat the cubitus varus deformity because locking plate could achieve better functional and cosmetic results and stabilize the distal humerus rigidly.

Anterior locking plate fixation versus cast immobilization for acceptably reduced extra- articular distal radial fractures: long-term follow-up of a randomized controlled trial.

This study reports the long-term results of a randomized controlled trial comparing anterior locking plate fixation with cast immobilization for extra-articular distal radial fractures. After 5.3 years of follow-up, no clinically relevant functional differences were found.

Effect of regular thicknesses on the microstructural and quantitative analysis for a hypo-eutectic ductile iron alloyed with Ni and V

Ductile iron contains free graphite nodules within the metallic matrix, which generally consists of ferrite and pearlite in the as-cast condition. The casting thicknesses have a great influence on the size, shape, and quantity of the microconstituents of the metallic matrix and the graphite nodules and thus on the mechanical properties. In this study the cooling rate (caused by the casting thicknesses) on the metallic matrix and the nodular characteristics of a low alloyed ductile iron with 0.8 %Ni and 0.15 %V was investigated. The ductile iron was produced in a sandwich process with ladle inoculation. Six plates of different thicknesses, from 4.3 mm to 25.4 mm, were produced in a green sand mold. The microstructural characterization was performed by optical microscopy (OM), scanning electron microscopy (SEM), and the image J software using different quantification methods. The area method to determine the average nodule size and nodular structure provided more reliable results than the perimeter and total particle count methods. The hardness test on the Rockwell C scale was used for the mechanical characterization. The low content of vanadium added to the ductile cast iron had a negligible effect on the solidification pattern, which was mainly due to the graphitizing impact of the nickel and silicon addition. The results of the microstructural characteristics are therefore primarily due to the cooling rate, which is determined by the casting thickness. The thinnest casting section significantly improved the number of nodules (414 Nod/mm2), sphericity (0.96), and nodularity (96.21 %). In contrast, the thickest casting plate obtained the highest volume fraction of graphite (10.85 %) and the lowest volume fraction of unwanted particles (0.36 %). The high cooling rate in the thinnest casting plate resulted in the highest hardness of 31.56 HRC due to the higher volume fraction of the pearlite (33.7 %) and carbides (4.5 %).

Effects of cooling rate on borides morphology and structure in cast β-solidifying γ-TiAl alloy

Borides have been found to play a significant role in determining the mechanical properties of cast TiAl alloys. In order to investigate the influence of cooling rate on the morphology and structure of borides, SEM and HRTEM techniques were utilized to analyze borides in Ti-43Al-4Nb-1Mo-0.5B (at. %) cast plates with varying thicknesses. A higher cooling rate was observed to result in the formation of elongated, curvy borides with high aspect ratios, increased planar faults, and complex structures consisting of a combination of B2 phase and various boride phases. Conversely, a slower cooling rate yielded shorter bar-shaped borides with fewer planar faults. This variation in boride morphology can be attributed to the differing thicknesses of the solute-rich layer, where the eutectic reaction occurs, at the solidification front during fast and slow cooling processes. Bf-TiB with a habit plane of (010) was identified as the dominant phase at all cooling rates. Borides in the [100] and [001] directions demonstrated a faster growth rate compared to those in the [010] direction. Additionally, HRTEM results indicated the presence of TiB2 while Ti3B4 was absent. This can be explained by the limited phase region of Ti3B4 in both the binary Ti-B and ternary Ti-Al-B phase diagrams, which is the smallest among all phases. These findings enhance the understanding of how cooling rate influences the morphology and structure of borides in TiAl alloys, thus providing insights for optimizing alloy design and manufacturing processes.

Estimation of Planar and Normal Anisotropy Parameters of Al 8011 Sheets as Cold Rolled and Cold Rolled with Annealed Condition

Aluminium 8011 cast plates subjected to cold rolling to reduce thickness from 12 mm to 3.5 sheets. As rolled aluminium sheet was subjected to annealing treatment after rolling. This work deals with the study of planar and normal anisotropy parameters of as rolled aluminium and rolled with annealed aluminium sheets. The tensile test samples were cut at 0°, 30°, 45°, 60° and 90° with respect to the rolling direction of as rolled Al sheet and rolled with annealed Al sheet. Tensile properties were measured at different orientations to the rolling directions. The wide variation in tensile strength was found in case of as rolled Al samples at different orientation to rolling direction of sheet (208 to 243 MPa). On the other hand nearly uniform tensile strength (128 MPa to 132 MPa) was measured for rolled and annealed Al samples at different orientations. As rolled Al samples shows anisotropic tensile properties where as isotropic tensile properties were measured for rolled with annealed Al samples. Al grains are more elongated along the rolling directions where as rolled and annealed Al sample shows more equiaxed grains which is attributed to isotropic behaviour of Al sheets. The normal anisotropy parameter or average rm value is higher (1.24) in case of rolled and annealed sheet sample as compared to as rolled Al sheet rm value (1.06). This is attributed to isotropic behaviour of rolled and annealed samples. Toughness and ductility properties are improved more than 3 times in case of rolled and annealed Al sheet samples. Annealing treatment of rolled Al sheet samples shows elongated grain morphology changes to equiaxed grains of aluminum which tends to improved formability and isotropic mechanical properties Al sheet. For determination of normal anisotropy (rm) value, tensile results R values are required at angles of 0 degrees, 45 degrees, and 90 degrees. However in this study additional R values are estimated at 30 degree and 60 degree in order to understand trend of R value at every 30 degree from 0 to 90 degree.

Thermomechanical Joining of Hypoeutectic Aluminium Cast Plates

Consistent lightweight construction in the area of vehicle manufacturing requires the increased use of multi-material combinations. This, in turn, requires an adaptation of standard joining techniques. In multi-material combinations, the importance of integral cast components, in particular, is increasing and poses additional technical challenges for the industry. One approach to solve these challenges is adaptable joining elements manufactured by a thermomechanical forming process. By applying an incremental and thermomechanical joining process, it is possible to react immediately and adapt the joining process inline to reduce the number of different joining elements. In the investigation described in this publication, cast plates made of the cast aluminium alloy EN AC-AlSi9 serve as joining partners, which are processed by sand casting. The joining process of hypoeutectic AlSi alloys is challenging as their brittle character leads to cracks in the joint during conventional mechanical joining. To solve this, the frictional heat of the novel joining process applied can provide a finer microstructure in the hypoeutectic AlSi9 cast alloy. In detail, its Si is finer-grained, resulting in higher ductility of the joint. This study reveals the thermomechanical joining suitability of a hypoeutectic cast aluminium alloy in combination with adaptively manufactured auxiliary joining elements.

Bacteriological Analysis of Iyiukwu Stream Water in Uhuagu Awgu L.G.A Enugu State, Nigeria

The majority of the population of the Iyiukwu community in the Awgu Municipal Area of ​​Enugu State in Nigeria depends on the Iyiukwu stream for its water supply. Due to the recent dcrease in cases of waterborne diseases, a study was conducted to examine the bacteriological characteristics of the Iyiukwu stream in order to protect public health from waterborne diseases. Five of this water samples taken from both the longitudinal profile and bottom level of the creek were tested for bacteriological properties using standard methods. Total bacterial counts were determined using the cast plate technique and total bacterial counts. From water samples three genera of bacteria genus Klebsiella Alcaligenes and Salmonella were isolated. Total bacterial counts in water samples ranged from 0 to 32 ×102 CFU/ml. Total bacterial counts in the water samples analyzed ranged from MPN index 0 to 39 for coliforms per 50 ml. It was concluded that not all stream water is suitable for consumption and appropriate measures should be taken to clean and treat stream water on a regular basis before drinking.

Preparation and functional characterization of the bio-composite film based on chitosan/polyvinyl alcohol blended with bacterial exopolysaccharide EPS MC-5 having antioxidant activities

In this study, the plate casting method was successfully used to prepare biocomposite films containing EPS from probiotic Enterococcus faecium MC-5 in combination with PVA and chitosan. The findings demonstrated that EPS was uniformly distributed in the film matrices and significantly improved the physicochemical properties of the resulting composite films. The development of intermolecular connections between the polymers was detected by high tensile strength and low water vapour transmission rate. EPS plays an important role in limiting the passage of UV- and visible light radiations through the films. FT-IR analysis was used to determine the molecular compatibility between the functional groups of the blended films made up of chitosan-EPS and PVA-EPS. The TGA results showed that composite films have a significant degree of thermal stability. The presence of amorphous peaks in the composite film was confirmed by XRD analysis. The EPS blended films displayed a greater antioxidant property than the PVA and chitosan films, as determined by DPPH and hydroxyl radical scavenging activities. Interestingly, the EPS-derived films showed enhanced metal chelation activity and strong antibacterial properties against Listeria monocytogenes and Staphylococcus aureus. EPS-based composite films performed better than chitosan and PVA films in terms of degradation rate. The overall functional characteristics of the EPS blended films suggested that they could be used as a packaging material to replace or reduce the use of conventional petroleum-based packaging materials.

Clarification of the anodic dissolution behavior of metallurgical structures during electrorefining of Al-Mn alloys in a 1-ethyl-3-methyl-imidazolium chloride-AlCl3 ionic liquid

Recycling Al is crucial to reduce the energy and environmental costs of Al manufacturing; however, the reclamation efficiency of high-quality Al from Al alloys is limited by the co-deposition of impurities during the electrorefining process. To address this issue, the anodic dissolution behavior of metallurgical structures within various Al-Mn binary alloys in 1-ethyl-3-methyl-imidazolium chloride-AlCl3 ionic liquid was investigated. During the constant-potential electrolysis of Al-1.5%Mn cast and cold-rolled plate alloys, an enriched layer derived from Mn solid solution was formed at an electrorefining potential of 0.2 V; this was attributed to preferential dissolution of Al in the matrix phase, followed by Mn accumulation at the Al surface. Furthermore, dissolution of the Al-Mn-Fe and Al-Mn intermetallic compounds occurred at 0.6 and 1.0 V, respectively; thus, the dissolution behavior of Mn in the Al-Mn alloys differed between the Mn solid solution in the matrix phase and the Mn-containing intermetallic compounds. These results indicate that by controlling the microstructure of the Al-Mn alloy and the applied anodic potential, the dissolution of Mn into the 1-ethyl-3-methyl-imidazolium chloride-AlCl3 electrolyte can be suppressed, thus preventing its co-deposition with Al on the cathode. This development is therefore anticipated to inform the development of electrorefining processes to obtain high-quality recycled Al for numerous manufacturing applications.

Performance Analysis of Fresnel Lens Driven Hot Water/Steam Generator for Domestic and Industrial Use: A CFD Research

In this study, the design, manufacture and thermal performance analysis of a Fresnel lens driven hot water/steam generator are presented. The designed system is suitable for domestic and industrial hot water/steam usage and can be easily scaled up to meet different capacity needs. In the first step of the research, thermal behaviour of the cast plate heat exchanger driven by a Fresnel lens with a concentration ratio of 100 is investigated at different working fluid velocities (0.6, 0.8, 1.0, 1.5 and 2.0 m/s) and at different absorber surface temperatures (700, 800, 900 and 1000 °C). Outlet temperature of working fluid from the cast plate heat exchanger is determined through a 3D CFD model for each case. The capacity of the steam generator for different operating times (h = 1, 2 and 3 hours) is also evaluated. The highest working fluid temperature at the outlet of heat exchanger is 914.8 °C for T_cp= 1000 °C and V_wf = 0.6 m/s. On the other hand, the lowest temperature is observed as 424.7 °C for T_cp = 700 °C and V_wf = 2.0 m/s. The steam capacity of the system for h = 3 hours is determined as 1696.5 and 508.9 kg in the best (V_wf = 2.0 m/s) and worst cases (V_wf = 0.6 m/s), respectively.

Effects of Hygrothermal and Salt Mist Ageing on the Properties of Epoxy Resins and Their Composites.

Epoxy and epoxide composites have a wide range of outdoor applications wherein they are affected by ageing. In this study, epoxy casting plates and epoxy-based composite rods for use in overhead conductors were prepared. A concurrent investigation concerning the ageing of epoxy resins and their carbon fibre composites was carried out via artificially accelerated experiments under hygrothermal and salt mist conditions. The moisture penetration along the depth, water absorption, appearance, hardness, density of the epoxy resins, and variation patterns of the impact strength and tensile strength of the epoxy-based composites were investigated. The ageing mechanisms were explored using Fourier transform infrared spectroscopy (FTIR) and scanning electron microscopy (SEM). Both ageing modes had essentially similar influences on the properties of the resins and their composites; moreover, they did not significantly affect the chemical structure and microstructure of the epoxy resin, with the physical adsorption of water primarily observed during the ageing process. The moisture absorption behaviour of the epoxy obeyed Fick's law. Although the water penetration rate in the salt mist ageing mode was slightly higher than that in the hygrothermal ageing mode during the early ageing stage, it was essentially the same during the later stage. The final moisture absorption rate at saturation was approximately 1.1% under both modes. The flexural strengths and impact strengths of the composites in both ageing modes followed a similar trend. They decreased gradually with the ageing time and then stabilized at almost the same value. The flexural strength was reduced from 803 MPa to 760 MPa and the impact strength from 383 J/m2 to 310 J/m2, indicating a decrease of approximately 5.4% and 19%, respectively. The absorbed water during the ageing process caused micro-cracks at the interface between the fibres and resin, weakening the interfacial strength and reducing the mechanical properties of the composites.

What's New in Hand and Wrist Surgery.

What's New in Hand and Wrist Surgery.

Numerical optimization of the taper a vertically cast plate

The temperature field of the studied plate was analyzed with different angles of widening in its cross section (in the range from 0° to 4.4°). From the inclined side, the plate was either insulated or uninsulated. Plastizol was used as an insulator. An uninsulated plate has a calculated optimum angular expansion of 3°. A widening of 2° is the minimum angle at which internal defects (e.g. shrinkage voids) begin to disappear. The insulated plate has an optimum angle of 2°. Using numerical calculations, it is possible to predict that after crystallization without insulation, the plate itself with a widening of 3° will have the same internal quality as a widening of 2° with insulation. The knowledge gained from this study can lead to a reduction in the volume of liquid metal used and also to a reduction in machining costs. These research results have already been successfully applied to the design of the technology for casting nodular cast iron cylinder liners.

Microstructural Characterization and Mechanical Properties Investigation of Nemalloy HE700 alloy: Effect of Pre-Solidified Grains

Structural plate castings of Nemalloy HE700 alloy, an Al-Fe eutectic alloy system with Zn and Mg as precipitation strengtheners were produced through high vacuum high pressure die casting (HVHPDC) and designed as an alternative to existing structural automotive materials. Cast materials are subject to the existence of pre-solidified grains (PSG) within the microstructure that originate from external solidification in the liquid melt and cause defects in the final cast components. In the case of HPDC, these PSG emerge in the shot sleeve and are injected through the gating system, influencing liquid metal flow behaviour and solidification characteristics. The extent of PSG and their distribution were manipulated through the altering of process route parameters such as shot delay intervals. Quantitative metallography and the effect of PSGs on the uniaxial tensile properties for the Nemalloy HE700 alloy are presented in this publication.

Methoding and Defect Minimization of Center Plate Casting by Auto-CASTX1 Software

The intense competition, in the world, for all components has compelled. All manufacturers try to manufacture parts with low cost, good quality, and on-time delivery. Nowadays, minimizing defects in casting is a significant issue in a foundry. Casting simulation has evolved into a useful tool for visualizing mold filling, solidification, and cooling and forecasting the location of internal flaws, including shrinkage porosity, sand inclusions, and cold closes. Controlling shrinkage porosity, inclusions, and cold run flaws have all improved dramatically. In this case, using a computer to replicate mold filling and solidification is beneficial to the foundry sector. It also increases the confidence in the quality of its castings and lowers the cost of rejection. It has also helped reduce the cost of methoding; simulation of casting processes is gaining acceptance in the foundry sector worldwide. It is being used to rectify existing castings, make new ones, and enable the emergence of new castings with no need for shop-floor trials. Because of its increased productivity, less energy and resources are required for melting and recycling. As energy is reduced, productivity improves, and as productivity rises, profit begins to rise as well. Metal casting technologies productivity and reliability are often under growing capable to improve high-quality components. In this paper, a contextual investigation on a center plate casting for replacing the current experimentation technique by using Auto-castX1 simulation software so that it can diminish the rejection rate from 8.5 to 3.5%. Simulation of the casting process has proved to be an effective tool in developing cost-effective and high-performance cast components.