Innovative Casting Research Articles

Novel Cast Ni‐Based Superalloys with Superb Weldability and Mechanical Properties Screened by a Multiperformance‐Oriented Criterion

Herein, innovative cast Ni‐based superalloys that not only withstand temperatures up to 800 °C but also offer superior weldability, robust tensile strength at both room and elevated temperatures, and a reduced density are introduced. The new Ni‐based superalloys are optimized via calculation of phase diagrams‐based high‐throughput thermal calculation and program‐controlled composition screening. A new multiperformance‐oriented criterion is devised, encompassing quantitative weldability indices, volume fraction of γ′, electron vacancy number, density, solidus temperature, and freezing range to optimize the alloy composition. Weldability indices, rooted in the solidification crack initiation mechanisms, prove equally applicable to both current interested alloys and commercial superalloys. The crack length of the optimized alloy after the constrained welding test is only 3.08% of the total weld length. It is unveiled that solidification cracking (SC) emerges as the pivotal factor governing the weldability of these alloys. The mechanism of SC for such superalloys is originated from the addition of Nb, Ti, Mo, and W, which results in the microsegregation of the composition and the precipitation of (Nb, Ti)‐rich constituents or M(Ta, Nb, Ti)C carbides in the liquid film of the central interdendritic region. This work hopefully helps to find promising candidates for the combustion chamber of aeroengines and other high‐temperature casts.

Beyond Tradition: "Figure of 8" Casting for Gartland Type 1 and Type 2A Pediatric Supracondylar Fractures of Humerus: Video Technique.

In the treatment of paediatric supracondylar humerus fractures (SCHFs), Gartland Type 1 fractures are traditionally managed with in situ above elbow casting, while Type 2A fractures are treated with closed reduction and above elbow casting. This technical note introduces a novel "figure of 8" cast technique for Type I and 2A fractures. The technique aims to maintain fracture reduction while reducing the risk of compartment syndrome by avoiding placement of cast material in the anterior elbow crease. This innovative casting method has the potential to enhance the management of these fractures in children, providing a alternative to conventional approaches. "Figure of 8" cast technique presents a unique, easy-to-implement, and effective approach for treating Type 1 and 2A SCHFs in children, maintaining fracture reduction in 100-110° elbow flexion and minimizing the risk of compartment syndrome.

High-entropy alloy reinforcement in aerospace-grade aluminum 7075: A study of yield strength and elastic modulus

This research aims to identify an appropriate theoretical model for assessing the yield strength and elastic modulus of a composite material consisting of aerospace-grade aluminum 7075 base matrix reinforced with nanocrystalline high-entropy alloy particle (HEAp) composed of CrCuFeMnNi. To fabricate the aluminum composite with a high-entropy alloy base, an innovative casting method was utilized. This method involved the use of a modified bottom-pouring stir casting furnace, integrated with a mechanical supersonic vibrator and a squeeze infiltration setup. The measured theoretical density was higher than the actual density, while the cast specimen exhibited porosity below 6.6%. Scanning electron microscopy (SEM) images revealed the presence of strengthening precipitates and a uniform dispersion of HEAp in the composite. Comparing the developed HEAp composites (CH2, CH3, and CH4) with the base AA7075 cast CH1 (AA7075 + 0 wt.% CrCuFeMnNi-HEAp), the ultimate tensile strength increased by 4% for CH2 (5 wt.% CrCuFeMnNi-HEAp), 21% for CH3 (10 wt.% CrCuFeMnNi-HEAp), and decreased by 9% for CH4 (15 wt.% CrCuFeMnNi-HEAp). Similarly, the yield strength increased by 10% for CH2, 24% for CH3, and decreased by 5% for CH4. The elongation showed an increasing trend of 5% for CH2, 12% for CH3, and 2% for CH4. The flexural strength of the HEAp composites (CH2, CH3, and CH4) increased by 2%, 5%, and 10%, respectively. The proposed model yielded similar yield strength values that closely aligned and were consistent with the experimental value within a deviation of 3.32%. The modified Halpin-Tsai models agreed with experimental value up to a reinforcement volume fraction of 4.89% when calculating the elastic modulus. The proposed model and the Hashin-Shtrikman upper bound also agreed on values up to a 3.32% reinforcement volume fraction.

Expert methods for the development of innovative technologies for the production of cast tools. Part 2. Choosing a priority technology

The development of an effective technology for casting billets for insert cutters of milling cutters of combine rotors for the extraction of potassium salt is considered, in particular, the strategic stage of the project associated with the selection and justification of the priority technology for producing cast billets. It is shown that methods of expert assessments are effective ways of organizing research at this stage of development. Keywords: innovative casting technology, research, development, expert assessment method. pavelserenkov@bntu.by, stl_minsk@tut.by, voranava.ts@gmail.com, alexander.chaus@stuba.sk

Alloy development and process innovations for light metals casting

The combination of light metals (aluminum, magnesium and titanium) and innovative casting processes provides cost-effective technologies to produce lightweight components and systems for many industrial applications. This article provides a comprehensive and yet critical review of light alloy development for cast components used in lightweight and high-performance structural and propulsion applications. It also summarized some latest process innovations in gravity casting, high pressure die casting, and low pressure casting, to overcome some fundamental issues related to defect formation in casting processes. Emerging casting processes developed in the last twenty years, such as semisolid processing, squeeze casting, ablation casting, bimetallic overcasting, and diffusion solidification processing, are discussed for further development. Recent advances in casting simulation and the concept of Integrated Computational Materials Engineering (ICME) are summarized for casting applications. Finally, future perspectives in light alloy development (including green alloys, high entropy alloys and metal matric composites), process innovations (such as high integrity casting, multi-material manufacturing and additive manufacturing), and ICME development are presented to stimulate further research and sustainable development in this important field of metals processing technology.

Proposal of an innovative casting technique for correction of clubfoot according to Ponseti method: a pilot study.

A total of 70 clubfeet were treated by a posterior above-knee cast (pressure points on the talus and on the first metatarsal) according to Ponseti method. At diagnosis, average Pirani score was 4.44, and mean time of treatment was 50.32 days. Overall, 27 (38.6%) clubfeet had only conservative treatment (5.29 casts) and 43 (61.4%) also had Achilles tenotomy (6.38 casts). At the end 61/70 feet (87.14%) had Pirani score 0; 10/70 feet (5.71%) had Pirani score 0.5. The Pirani score gain/cast was β=-0.432 (P<0.001). This new casting technique is safe and effective at avoiding some adverse issues related to the removal of the conventional cast.

Thermal energy storage characterization of cement-based systems containing microencapsulated-PCMs

This work reports a detailed experimental study that is aimed at investigating the Thermal Energy Storage (TES) performance of cementitious systems containing Microencapsulated Phase Change Materials (MPCMs). New spherical-shaped test specimens for TES measurements were produced following an innovative casting technique, developed at the Institut für Werkstoffe im Bauwesen – TU Darmstadt. Three water-to-cement ratios and three MPCMs volume fractions, leading to a total of nine different mixtures, were investigated. The thermal experiments were accompanied by mechanical tests to observe the effect MPCMs have on the resulting strengths in both compression and bending. The analysis and discussion of the TES results are employed for calibrating an enthalpy-based model. The experimental data have been applied to evaluate the corresponding temperature-based material parameters like specific heat, conductivity, or more in general, the energy storage capacity of a system under transient heat conduction conditions.

Corrosion Resistance of Injection-casting Dental Implants

In this paper the results of corrosion resistance for dentistry implants � commercial and produced by injection casting were presented. The produced and commercial implants were made from the same material (Ti6Al4V ELI). Studies were carried out on six samples: two were input materials (E1, E2), two were commercial implants (C1, C2) and two were produced implants (P1, P2) where P1 was produced from input material E1 and P2 was produced from input material E2. For corrosion resistance potentiodynamic studies were carried out. It was found that produced samples through injection casting have better corrosion resistance than commercial implants. However, produced implants have similar corrosion resistance to input materials. The studies have shown that it is possible to use innovative injection casting to improve corrosion resistance of dental implants.

Needle electrode-based microplasma formed in a cavity chamber for optical emission spectrometric detection of volatile organic compounds through a filter paper sampling

A novel microplasma device, which generates discharge in a Poly (dimethylsiloxane) (PDMS) cavity chamber with two normal syringe needles, serving as both gas channels and electrodes, was prepared by an innovative casting technology. This microplasma device maintains a stable discharge even after working under large periods of time (4h) and even if impurity deposition is produced on the needle electrode tips. The cavity discharge chamber of this device can also be used as a sampling compartment. 14 kinds of volatile organic compound (VOC) samples, with 6 series depending on carbon chain structures and boiling points (from 34.6 to 232.9°C), can directly diffuse into the plasma by using a filter paper. The filter paper was placed right under the microplasma zone in the chamber. Most VOC samples could be well detected (<20min for each) and discriminated in this microplasma system through a portable spectrometer. Combined with the peak ratio (300–900nm spectrometric range available) analysis, discharge parameters, specific characteristics of each sample and comparison of each homologous group could be systematically made by this device. The present work proposes a new approach for fast screening of volatile organics in water bodies or other solvents. The utility of this device was demonstrated by that BTEX-containing aqueous samples, as an example, could be detected at 50mg/L level with detection limits of 2.5μg/L.

International Symposium on Liquid Metal Processing & Casting 2015 (LMPC2015)

Preface: International Symposium on Liquid Metal Processing and casting (LMPC 2015), 20-24 September 2015, Leoben, AustriaWe are delighted to come up with thirty eight (38) contributed research papers selected from the proceedings, as an output of the international Symposium on Liquid Metal processing and casting held in Leoben, Austria, from September 20-24, 2015. This event marks the eleventh such event in a highly successful series of symposia devoted to this important technical field. This symposium gathers industrial and scientific communities in the field of melting, refining and casting of special metals and alloys. Contributions cover a wide range of topics including vacuum arc and electro slag remelting, process modeling, innovative casting techniques, segregation, and liquid metal treatment and refining.Papers from both the presentation and poster sessions are included in this symposium volume. It is divided into the following six topic areas: Electro slag Remelting, Vacuum remelting, Magneto-hydrodynamic applications in metallurgy, ingot casting, continuous casting, and special metallurgy.More than half of the papers are directly concerned with mathematical modelling and numerical simulation, although experimental and industrial full- scale processing are also included. Steel, superalloys and titanium are the major materials investigated, while the processing of aluminium, silicon, copper and reactive metals are also addressed.The conference co-chairmen are grateful to the scientific committee and all the reviewers of the papers for their efficient work done in a very short period of time. These proceedings would not have been possible without the tremendous help of Andreas Ludwig from the Montanuniversität Leoben. Thanks to TMS for promoting the conference to their members around the world. Finally, we would like to thank ASMET (The Austrian Society for Metallurgy and Materials) for helping with registration and local organization in particular Bruno Hribernik, Melanie Baumgartner and Yvonne Dworak.Abdellah Kharicha and R. Mark Ward,Conference Co-chairs and Co-editorsabdellah.kharicha@unileoben.ac.atLMPC 2015

Cyclic behaviour of beam-to-column joints with cast steel connectors

This paper presents a comprehensive study on steel beam-to-column joints equipped with weld-free cast steel connectors used as replaceable energy-dissipating components. The basic idea was to use the connectors as the main source of deformation and energy dissipation, and to realize rapid repair of the joints by simple replacement of theses connectors after earthquakes. The research commenced with tests on five full scale specimens, including one specimen with conventional welded T-stub connectors and four specimens with the innovative cast steel connectors. The specimens with cast steel connectors were shown to have good energy dissipation capacity with stable and plump hysteretic curves, and the equivalent viscous damping could achieve up to 37.5%. These joints were also shown to meet the classification criteria of semi-rigid joints in terms of stiffness, and the ductility, which was governed by fracture of energy dissipating elements, was found to be satisfactory. The presence of shear tab connection was found to increase the initial stiffness and ultimate strength of the joints, but the energy dissipation was not significantly improved. Importantly, the yielding regions and main source of energy dissipation were limited to the cast steel connectors, while the adjacent structural members remained in the elastic range, indicating minimal repair work in the aftermath of earthquakes. For a further understanding of the proposed joints, finite element models were established, and based on test and numerical observations, preliminary design recommendations, including those on cast steel connector detailing and normal component-based joint design strategies, were finally outlined.

INVESTIGATIONS ON COATING OF DIES FOR ADVANCED SQUEEZE CASTING PROCESS

Premature failure of dies is a critical problem of manufacturers in hot-working processes, e.g. metal die casting, hot extrusion and/or thixoextrusion of aluminium/magnesium or steel. Typically, die material has to be resistant to heat cycling or corrosion environment, to plastic deformation and wear, especially when exposed to high temperature during continuous working cycle. The resistance of dies could be increased by the modification of their surfaces, i.e. by the application of an adequate coating. An improvement of the resistance of H11 steel substrate will be presented and discussed. Here, the coatings will be realized through both by High Velocity Oxy-Fuel coating spray method and by plasma spray method. Firstly, the measurement of the residual stress will be carried out on the un-coated and coated substrate. Secondly, morphological analysis by optical and scanning electron microscopy will be performed on the powders used for the coating and on the coated materials. Such investigations aim finding the most favourable conditions, as concern the materials to be employed for the deposition and the more appropriate deposition techniques, in order to achieve improved properties for the dies which can be used in innovative casting techniques, i.e. squeeze casting and/or some related modified processes.

The use of LPR (logic of plausible reasoning) to obtain information on innovative casting technologies

The paper presents a methodology for the application of a formalism of the logic of plausible reasoning (LPR) to create knowledge about a specific problem area. In this case, the methodology has been related to the task of obtaining information about the innovative casting technologies. In the search for documents, formulas created in terms of LPR have a much greater expressive power than the commonly used keywords. The discussion was illustrated with the results obtained using a pilot version of the original information tool.

CIGÜEÑALES DE FUNDICIÓN ESFEROIDAL CON PROPIEDADES MECÁNICAS MEJORADAS EN ESTADO BRUTO DE COLADA

ABSTRACT: Current understanding about the influence of several alloying elements on mechanical properties of steels and cast irons and more precisely on ductile cast irons is still incomplete. On the other hand, an increasing demand to develop innovative and cheap cast iron alloys with improved mechanical properties and potential application on high performance components is also observed. Crankshafts used to manufacture high-power engines for big vehicles are a proper example of this demand. The present work is devoted to study the effect of several chemical alloying elements on the structural and mechanical properties of fully pearlitic ductile cast irons. An optimized combination of C, Si, Cu, Mn Mo and Cr contents has leaded to develop a new methodology for preparing as-cast ductile irons with more homogeneous matrices, tensile strength values even higher than 1000 MPa and elongation values higher than 4%.

Comparative study on stiffness properties of WOODCAST and conventional casting materials

Plaster-of-Paris and synthetic materials (e.g. fibreglass) have been in clinical use as casting materials for decades. An innovative casting material, WOODCAST, brings interesting alternatives to the traditional materials. The aim of this study was to compare the stiffness properties of the WOODCAST material to traditional casting materials. In immobilization by casting, materials with variable stiffness properties are required. Ring stiffness of cylindrical samples correlates well with cast rigidity. For load-bearing structures, the use of the WOODCAST Splint is recommended as equally high stiffness was obtained with the WOODCAST Splint as was with fibreglass. The WOODCAST 2 mm product is optimal for structures where some elasticity is required, and WOODCAST Ribbon can be used in any WOODCAST structure where further reinforcement is needed. The results show that WOODCAST material can be used in replacing traditional casting materials used in extremity immobilization. The mechanical properties of casting material play an important role in safe and effective fracture immobilization. Stiffness properties of the WOODCAST casting material and conventional materials - fibreglass and plaster-of-Paris - were analysed in this study. The WOODCAST Splint appears to compare favorably with traditional materials such as Scotchcast.

6.1: High Performance VA‐LCD Compensation Film Made with Environmentally Friendly Material for VA‐LCD

AbstractWe have successfully developed a novel compensation film, EVE‐film Environmental friendly film for VA‐LCD performance Enhancement, which improves VA‐LCD performance with less environmental burden. We satisfactorily realized optical designs of EVE‐film by controlling the internal haze, wavelength dispersion, and optical anisotropy, with innovative casting process. After all our efforts, VA‐LCD using EVE‐film exhibited 13% higher contrast and a color‐shift significantly better than our previous compensation film.

Controlled Diffusion Solidification of 2024, 6082 and 7075 Al Alloys via Tilt-Pour Casting Process

Controlled diffusion solidification (CDS) is an innovative casting route for Al alloys to obtain a cast part with a non-dendritic morphology of the primary Al phase during solidification, similar to those obtained in the semi-solid rheocasting process. The process involves mixing two alloy melts with specific individual compositions and temperatures to produce the desired final alloy by mixing and immediately casting in a mould. CDS enables sound shaped casting of Al based wrought and cast alloys with a non-dendritic microstructure. The two pre-cursor alloys will have to be chosen from a critical study of the various isopleths of the multi-component phase diagrams for the respective alloys along with laboratory experiments. Further, the favorable melt superheat temperatures of the two pre-cursor alloys were evaluated from laboratory experiments as well. A tilt-pour mould designed and validated to cast tensile test bars was used for the study. The aim of the study was to demonstrate the feasibility of manufacturing sound shaped castings via the CDS route for alloys which have been impossible to shape cast in a permanent mould process due to the detrimental hot-tearing problem during solidification. The present work defines process conditions to enable shaped casting of the Al wrought alloys 2024, 6082 and 7075 by the tilt-pour casting technique. Sound casting and a favorably non-dendritic microstructure were obtained for these alloys during solidification in a ceramic crucible as well as in a metallic mould via the tilt-pour casting process. Further work is underway to optimize various process conditions and develop new heat treatment cycles for parts cast by CDS to maximize mechanical properties for these alloys.

1A1-F04 プレスキャスティングにおける上昇流動液体の飛跳ね挙動のモデリングと空気巻き込み抑制を考慮したプレス速度設計(生産システム・生産機器メカトロニクス)

This paper presents modeling of liquid upward flow and design of pressing velocity considering air entrainment suppression in press casting process. In this study, the problem of air entrainment is focused on an innovative casting method called "Same Mold Press Casting". This method has two molds which are an upper mold and a lower mold, molten metal is directly poured into the lower mold without a runner, and then pressed to fill the cavity by the upper mold being lowered down. Thus, fluid of molten metal which was turbulent by moving upper mold has air entrainment. Then, air entrainment are suppressed by modeling of liquid upward flow has been clarified.

Experimental study and numerical analysis on heavy-duty cast steel universal hinged supports for large span structures

Heavy-duty cast steel universal hinged supports are gaining increasing usage in modern large-span structures, offering extremely large individual load carrying capacity and universal rotation ability which is preferable to release temperature effects and to improve force conditions of lower structures. This paper presents a full-scale experimental study and elastic-plastic finite element (FE) analysis on the performance of an innovative heavy-duty cast steel support. The support is composed of three main components, i.e. an upper one, a lower one and an intermediate rotation pad. External loads are designed to be passed and transferred through the contact interaction of the three casting parts. The support studied in this paper is expected to possess a higher capacity than existing supports while having the ability of universal rotation under heavy loads. Three full-scale static experiments corresponding to three typical load cases (i.e. tension-shear load case, compression-shear load case, and shear-tension load case, respectively) have been carried out employing a multifunctional loading device. A three-dimensional FE model was developed using the commercial software ANSYS, considering the contact behavior between the support components and accounting for both material and geometrical nonlinearities. The model was validated against the experimental results reported in this paper. The performance of this support was evaluated in accordance with a Chinese national code ‘Technical specification for application of connections of structural steel casting (CECS 235:2008)’. This study concluded that this type of support performs well and that it could be used for realistic applications.

Semi-solid casting (SSC) of zinc alloy nanocomposites

An innovative casting method that combines semi-solid casting (SSC) and metal matrix nanocomposite (MMNC) technology was successfully demonstrated. The method uses the grain refining properties of the nanoparticles in the MMNC to produce slurry with the appropriate globular structure for semi-solid casting. In this way no additional material processing or mechanical agitation is necessary to achieve the desirable slurry microstructure. The grain refining attributes of the nanoparticles were shown to stem from the promotion of nucleation in the solidifying matrix alloy. Differential scanning calorimetry (DSC) showed a reduced undercooling necessary for nucleation owing to the nucleation catalytic potency of the nanoparticles. Using this method zinc alloy AC43A nanocomposite with 0.5 wt.% SiC β nanoparticle additions were cast at a 30% solid fraction. The resulting castings showed increased ductility, reduced shrinkage, and increased strength compared to their monolithic liquid cast counterparts.