Properties Of Castings Research Articles

Comparison of microstructure, damping capacity, and mechanical properties of cast and deformation processed Fe17Mn alloys

There were few works on cast FeMn damping alloys although many studies have been conducted on deformation processed (DP) counterparts. In this study, we investigated the differences in damping and mechanical properties of as-cast and as-DP Fe17Mn alloys and the effect of solution treatment at 1050℃ (ST) on their properties. The as-cast Fe17Mn alloy demonstrated a higher damping capacity but lower strength than the as-DP Fe17Mn counterpart. As much as 18 % of the BCC phase was distributed as dendrite in the Mn-depleted region of the as-cast Fe17Mn alloy. The DP Fe17Mn alloy inherited some BCC phase with less than 1 % content formed during the casting. The ST further improved the damping capacity and plasticity but decreased the strength in both the cast and DP Fe17Mn alloys. After the ST, the cast Fe17Mn alloy also showed good mechanical properties, with tensile strength up to 645 MPa and fracture up to 40 %. Our results shed light on the potential application of cast Fe17Mn alloy in mechanical components.

Additive Manufacturing for Rapid Sand Casting: Mechanical and Microstructural Investigation of Aluminum Alloy Automotive Prototypes

The automotive industry is undergoing a rapid evolution to meet today’s challenges; therefore, continuous innovation and product development are needed. Validation tests on prototypes play a crucial role in moving new components into industrial production. There is also a pressing need for faster prototyping processes. In this context, rapid sand casting (RSC), based on additive manufacturing technology, offers a promising solution for a quick production of sand molds. While this technology is already employed in the industry, the need to deepen the general understanding of its impact on the casting properties is still a relevant item. In this study, different geometries of automotive prototypes made of aluminum EN AC 42100-T6 alloy were experimentally analyzed. Microstructural examinations, tensile tests, and fractography and porosity analyses were conducted. The findings demonstrate the considerable potential of RSC, giving, in general, high mechanical properties. A comparative analysis with prototypes produced through traditional sand casting revealed similar results, with RSC exhibiting superior yield strength and stress at brake. However, both technologies revealed a reduced elongation percentage, as expected. Future efforts will focus on standardizing the RSC process to enhance ductility levels.

Effects of Fe content on the 3D morphology of Fe-rich phases and mechanical properties of cast Al-Mg-Si alloy

Fe is a common impurity element in recycled aluminum scraps, and adjusting Fe content can effectively promote the effective utilization of recycled aluminum. In this study, Al-Mg-Si-Mn-Fe alloys with different Fe contents were prepared by adding various percentage of aluminum scraps. Synchrotron X-ray tomography technology was used to study the morphological evolution of Fe-rich phases and corresponding effect on mechanical properties of studied alloys. The results showed that as the Fe content increased, the 3D morphology of Fe-rich phases changed from fine Chinese-script and needle-like shapes to coarse Chinese-script structure. Their 3D morphology was mainly composed of thin platelets and curved branches. The increase in Fe content did not significantly change the 3D structure of Fe-rich phases, but increased the volume fraction of large Fe-rich phases. When the Fe content reached 0.35 %, the maximum volume and the number of branches of individual phases increased by 182.9 % and 142.2 %, respectively, compared with the 0.2Fe alloy. With the increase of Fe content, the ductility of alloys gradually decreased, especially when the Fe content exceeded 0.25 %. The Fe content had a small effect on the liquidus temperature of alloys, but it changed the initial formation temperature and type of Fe-rich phases. When the Fe content exceeded 0.32 %, it promoted the formation of β-Fe phase, which may be the main reason for the significant decrease in ductility of studied alloys with higher Fe content.

Implementing shear-punch test for the assessment of mechanical properties of cast and selective laser melted AlSi10Mg alloys

Implementing shear-punch test for the assessment of mechanical properties of cast and selective laser melted AlSi10Mg alloys

Вплив температури розплаву і вібрації на структуру сплаву АМг6

A wide range of products, including pipes, is made from cast billets of the Al-Mg alloy. It is known that the alloy effectively combines a complex of special properties. The article is devoted to the study of the possibilities of improving the properties of AMg6 alloy castings by applying vibration during casting and cooling. The vibration of the melt in the casting mold during cooling and solidification is an effective auxiliary tool for controlling the structure of alloys, which is universally integrated into the technological process of obtaining cast blanks. In this work, the influence of the melt pouring temperature and vibration (amplitude 0.2 mm, frequency 60 Hz) on the size, morphology and nature of the arrangement of phases and mechanical properties of the cast metal of tube blanks made of AMg6 alloy was investigated. It was found that the use of vibration leads to a 10-fold decrease in grain size. It was found that Mg2Si inclusions did not change shape under the influence of vibration, but decreased in size by 1.5 times. Similar changes in the structure of the alloy are characteristic of the metal, which was cooled at a higher speed and with the use of vibration. This made it possible to obtain the hardness of the AMg6 alloy up to 717 MPa, which is higher than that of the standard material. Grinding structural components makes it possible to reduce the duration of heat treatment of the alloy Keywords: AMг6 alloy, cast pipe billets, vibration, structure, mechanical properties.

A novel and effective approach to improve the oxidation resistance and slag corrosion resistance of Al2O3–SiC–C castables

The present study aims to clarify the role of ball pitch in Al2O3–SiC–C (ASC) refractory castables and investigate the influence of low temperature treatment on the composition, microstructural evolution, and properties of ASC refractory castables. By utilizing the expansion properties of ball pitch during heating, the castables undergo a low temperature treatment to induce the flow and expansion of ball pitch within the castables. This, in turn, fills the surrounding pores and enhances the physical properties of the castables. The results of this study demonstrate that low-temperature heat treatment of the castables at temperatures at 350 °C significantly improves the hot modulus of rupture, oxidation resistance, and slag resistance after sintering. This improvement is attributed to the optimized microstructure. In comparison to the corresponding samples without low temperature treatment, the high temperature modulus of rupture (HMOR) of the calcined castables treated at 350 °C increases by 33.3%. Additionally, the oxidation index and slag corrosion index after sintering at 1500 °C decrease by 39.6% and 87.31% respectively for the samples low temperature treated at 350 °C, as compared to the samples low temperature treated at 110 °C. This study provides a fresh perspective on the production of ASC castables with exceptional high temperature performance.

Influence of intermediate carbon content on the microstructure and high-temperature mechanical properties of cast and wrought Ni-based superalloy nimonic 105

NIMONIC® 105 variants with three different carbon concentrations were manufactured. The medium carbon content variant shows inferior creep properties due to a bimodal grain size distribution and non-uniform carbides repartition leading to plastic strain accumulation between the two domains. This eventually facilitated facile cracking and void formation during high-temperature creep.

CHANGES IN THE STRUCTURE AND PROPERTIES OF ALUMINIUM ALLOYS WHEN MODIFIED WITH POWDER COMPOSITIONS

Purpose. To determine the effect of modification with powder compositions on the structure and mechanical properties of cast and deformed aluminium alloys. Research methods. Metallographic analysis, stereometric metallography, testing of strength and plastic properties of cast alloys AL4, AL4C of the Al-Si system and deformed alloys 1545 of the Al-Mg-Sc system, 2219 of the Al-Cu-Mn system in their original and modified state. Results. Meltings of AL4, AL4C, 1545, 2219 alloys were carried out in the initial state and with melt treatment with a complex nano-disperse modifier of magnesium silicide Mg2Si and silicon carbide SiC with a particle size of 50...100 nm. The optimal content of Mg2Si+SiC (0.10%) for increasing σ0.2 of aluminium alloys was determined. A 1.6-fold reduction in the grain structure of cast alloys was achieved. The dependence of the particle size and the amount of the modifier on the mechanical properties of the alloys was established. In industrial experiments, the most effective particle size of Mg2Si+SiC was established for increasing σ0.2 of AL4, AL4C alloy from 115 to 260 MPa in the as-cast state. The increase in the strength properties of the modified alloys is 44 % compared to the original state. Scientific novelty. Further development, insight into the influence of melt modification on the parameters of the structure and properties of aluminium alloys was obtained. The use of nanodispersed complex modifier Mg2Si+SiС with a particle size of 50...100 nm is proposed. It has been confirmed that the use of complex nanodisperse modifiers allows you to actively influence the structure and mechanical properties of aluminium alloys. Practical value. It has been experimentally proven that the rational amount of the introduced complex modifier is 0.10% of the mass of the melt. A significant grinding of the grain structure and an increase in the strength properties of cast and deformed aluminium alloys were achieved as a result of the modification.

Intelligent optimization design of squeeze casting process parameters based on neural network and improved sparrow search algorithm

Squeeze casting process parameters are the key to squeeze casting production and to obtain excellent performance casts. To realize intelligent optimization design of process parameters under various requirements, this work presents a new intelligent optimization design framework for squeeze casting process parameters based on process data and integrating a two-stage intelligent integrated optimization. To adapt to diverse optimization applications of different process and target parameters, the backpropagation (BP) neural network and existing process data are utilized to intelligently establish the incompletely determined correlations between process parameters and squeeze cast quality or properties. An improved sparrow search algorithm (LCSSA) is developed and integrated to optimize both the aforementioned model structure and intelligently obtain the optimal solution, that is, the two stages of optimization. For the purpose of assessing the effect of each performance on the combination of process parameters, the information entropy weight approach is used. Various application cases and experiments have been conducted to evaluate the effectiveness of the suggested intelligent optimization design framework. It is indicated that the proposed method is practicable and can intelligently achieve ideal process parameters with high accuracy even based on small-scale data samples. The solving efficiency and optimization accuracy of LCSSA are superior than those of other intelligent optimization algorithms like the genetic algorithm (GA). The proposed framework outperforms the mixture of the BP neural network and other traditional optimization algorithms.

Research Progress and the Prospect of Damping Magnesium Alloys.

As the lightest structural metal material, magnesium alloys possess good casting properties, high electrical and thermal conductivity, high electromagnetic shielding, and excellent damping properties. With the increasing demand for lightweight, high-strength, and high-damping structural materials in aviation, automobiles, rail transit, and other industries with serious vibration and noise, damping magnesium alloy materials are becoming one of the important development directions of magnesium alloys. A comprehensive review of the progress in this field is conducive to the development of damping magnesium alloys. This review not only looks back on the traditional damping magnesium alloys represented by Mg-Zr alloys, Mg-Cu-Mn alloys, etc. but also introduces the new damping magnesium materials, such as magnesium matrix composites and porous magnesium. But up to now, there have still been some problems in the research of damping magnesium materials. The effect of spiral dislocation on damping is still unknown and needs to be studied; the contradiction between damping performance and mechanical properties still lacks a good balance method. In the future, the introduction of more diversified damping regulating methods, such as adding other elements and reinforcements, optimizing the manufacturing method of damping magnesium alloy, etc., to solve these issues, will be the development trend of damping magnesium materials.

Investigation into relationships between grain size distribution characteristics and mechanical properties in large-scaled complex titanium alloy castings utilizing LASSO regression

Investigation into relationships between grain size distribution characteristics and mechanical properties in large-scaled complex titanium alloy castings utilizing LASSO regression

Effect of Mn substitution on Cr in the Al-Cu-Er-Mg-Zr-Fe-Si-Ti cast alloy

The microstructure, phase composition, precipitates evaluation, casting, and mechanical properties of the novel cast Al-4Cu-2.1Er-1Mg-0.2Zr-0.2Cr-0.15Fe-0.15Si-0.1Ti alloy were analyzed using by optical microscope, scanning and transmission electron microscopes, differential scanning calorimetry, thermodynamic calculations, hot cracking and mechanical properties measurements. The positive effect of Cr as a substitution of Mn on plasticity and precipitation strengthening was demonstrated. The 0.2Zr, 0.2Cr and 0.1 Ti as a grain refiners provide a fine grain size of 25 μm in the as-cast state due to primary Al75–80Cu10–12Er3–4Cr7 phase particles formation as a nucleation centers of Al. The hot cracking index (HCI) of the AlCuErMgCr alloy was 12–14 mm which is similar with HCI of the cast Al-Si-Cu-Mg alloys. The good casting properties in the AlCuErMgCr alloy achieved due to a fine grain structure and narrow solidification range. The contribution of the Al3(Zr,Er) (40 nm), Al45Cr7 (6 nm), and S’(θ’) (100/5 nm) precipitates is 38.5 MPa, 140.4 MPa, and 198.9 MPa and the calculated contribution from dislocation and precipitates is 262.3 MPa. The ultimate tensile strength (UTS) and elongation (El.) of the AlCuErMgCr alloy are 372 MPa and 6% which is higher in 16.6% and 150%, respectively, than in the Mn-containing alloy. Novel alloy has an excellent combination of yield strength (YS) and plasticity at 20–250°C. The YS and El. are 301 MPa and 6% and 225–250 MPa and 4.6–11.5% at 20 and 200–250°C, respectively. The rupture strength at 250°C after 100 h (σ100250) is 106 MPa. Mechanical and casting properties of the novel alloy are superior to the properties of commercial 201.0 (Al-Cu-Mn-Mg-Ag-Ti) alloy.

Evolution of microstructure and mechanical properties in large-scaled complex titanium alloy castings during service based on quantitative abnormal microstructure analysis

This investigation delves into the microstructural heterogeneities of large-scale complex titanium alloy castings (LCTACs), with a specific focus on the emergence of abnormal coarse grains (ACGs), which pose a potential threat to the casting's operational longevity. This comprehensive analysis meticulously maps the spatial distribution of ACGs within the LCTAC, employing statistical methodologies to examine these grains across different zones subjected to varying service durations. The study reveals a nuanced correlation between wall thickness and the tendency for microstructural coarsening during operational life, concurrently tracing the evolution of mechanical properties in typical zones. Results demonstrate a distinctive 'staircase-like' progression in grain size distribution, accentuated as wall thickness increases. Throughout the operational lifespan, microstructures in zones of differential wall thickness exhibit varied degrees of growth. Notably, zones with thicker walls display a more marked enlargement in microstructure. This phenomenon coincides with a substantial increase in the extent of ACGs, ultimately leading to a significant diminution in mechanical properties, evidenced by a reduction exceeding 15% in both tensile and yield strength.

Effects of Titanium, Cerium or Aluminum Addition on Microstructure and Mechanical Properties of Ductile Iron Castings

Effects of Titanium, Cerium or Aluminum Addition on Microstructure and Mechanical Properties of Ductile Iron Castings

Effect of Hot Pressing on the Optical, Thermal, and Dielectric Properties of Solution Cast Prepared Nanocomposite Films Based on a Poly(Vinylidene Fluoride-co-Hexafluoropropylene) and Poly(Ethylene Oxide) Blend Matrix with Dispersed Zinc Oxide Nanoparticles

In our research described herein, the hot pressing treatment at 90 °C under 2 tons of pressure on solution cast polymer nanocomposite (PNC) films based on a host matrix of poly(vinylidene fluoride-co-hexafluoropropylene) (P(VDF-HFP)) and poly(ethylene oxide) (PEO) with varying polymer blend compositions (20, 50, and 80 wt% P(VDF-HFP) or PEO) and 2 wt% zinc oxide (ZnO) nanofiller, was performed; the effects of this treatment and the composition variations on the optical, thermal, and dielectric properties was explored. The ultraviolet-visible wavelength range study revealed slightly reduced absorbance and a little increased energy band gap after the hot pressing of the nanocomposite films. Differential scanning calorimetry of the solution cast-hot pressed (SC-HP) PNC films explained the reduced thermal stability of the poly(ethylene oxide) crystallites and also the degree of crystallinity. The broadband dielectric measurements of these materials, at 27 °C, confirmed significant changes in various dielectric polarization processes, demonstrating a large redistribution of constituent interfaces by the hot press treatment. Additionally, the 90 °C hot pressed PNC film of equal polymer compositional ratio was further hot pressed at 130 °C and 160 °C, step by step, and characterized to examine the variations in dielectric properties. The properties of these thermally treated composite films are discussed concerning their use for flexible device applications.

Comparative Studies of Microstructural, Mechanical and Tribological behaviour of A319 alloy cast in solid waste mold and conventional sand Mold

Abstract This study investigates the potential of utilizing industrial solid waste (blast furnace slag, ferrochrome slag, and red mud) as mold materials to improve the solidification rate and wear resistance of A319 alloy. Unlike conventional molds such as silica sand and olivine sand, industrial solid waste poses an eco-friendly alternative, contributing to waste valorization. The motivation for this research drives the need for sustainable and efficient waste management practices in the industrial sector. By exploring the utilization of industrial solid waste as a mold material, study aims to address the current challenges in disposal, reduce environmental impact, and enhance the overall performance of A319 alloy through improved solidification and wear resistance. The experimental phase involved multi-factor reciprocating sliding wear tests conducted on a sample using a linear reciprocating tribometer, employing a steel ball as a counter face. The investigation of reciprocating wear characteristics aimed to assess the correlations between solidification rate and wear properties of a specimen cast in an industrial solid waste mold as well as a sand mold. Notably, tribological test results revealed a low wear rate of 3.3 mg/Km for the blast furnace slag mold. The scanning electron microscopy (SEM) image of the wear surface showed adhesive wear mechanisms. This study contributes valuable insights into the potential environmental and performance advantages of repurposing industrial solid waste for foundry applications.

“Experimental Assessment Of Microstructure And Corrosion Properties Of Sg Iron (400/15 Grade) Under As-Cast And Nitrotec Treated Condition”

Spheroidal Graphite (SG) iron castings (conforming to IS 400/15 grade) are made in green sand moulds. Test specimens are then machined from the castings. One set of Specimens is then subjected to Nitrotec Treatment, treating the surface with nitrogen atmosphere which resulted in the formation of Fe3N layer. The Nitrotec temperature selected is 5700C and 6300C. Specimen is held at this temperature for a fixed duration of 180 minutes and then quenched in quench bath (water based quenchant) maintained at 500C. The effect of Nitrotec Treatment on microstructure and corrosion is studied and compared with as-cast ones. The results of the research indicate the Graphite nodules are more or less uniform and distributed evenly in the ferritic matrix. The nodules count shows an average of 90 nodules/mm2. Corrosion or rusting is essentially a process of oxidation in which iron combines with water and oxygen to form rust, the reddish-brown crust that forms on the surface of the iron. Nitrotec treated specimen treated at 570º C exhibit lower corrosion rate compared with the ones treated at 630º C. This may be due to the higher hardness values obtained for low Nitrotec temperature treated ones. From the above investigation it is clear that the Nitrotec treatment has an effect on the microstructure and corrosion properties of SG iron castings leading to further investigation on Nitrotec treated SG iron by changing different parameters.

The Elasticity Of Caste In The Sikh Diaspora: Jat Cool and Caste Masculinities in the Pacific Northwest

Abstract: This article examines the transnational dimensions of caste and gender in the Punjabi Sikh diaspora of the Pacific Northwest. I explore how Jats (a landowning caste from Punjab, India) have positioned themselves at times as superior to Chamars (Punjabi Dalits or caste oppressed peoples) in the US-Canada borderland diaspora. Though Sikhism is a religion founded on anti-caste origins, the simultaneous repudiation of caste and celebration of Jat pride paradoxically illustrates structures of caste within the religion. The article unsettles the ways in which Jat men in the diaspora can be implicated in Jat pride and Jat cool: a social currency intertwined with popular culture and social media that reveals a particular caste masculinity. While not all Jats engage with Jat pride, and in fact many are involved in anti-caste praxis, it is important to situate the pervasiveness of these hierarchical ideologies within intra-Sikh communities to understand the permutations and stickiness of caste within the diaspora. I build on Asian American approaches to theorizing caste, youth cultures, and notions of “cool” to ultimately reveal how caste, rather than fixed or natural, is an elastic concept that is contingent upon how it is deployed within Sikh diasporic geographies and temporalities.

Calculation of the thermoplastic beryllium oxide slurry molding with ultrasonic activation

The article presents the results of assessing thermal shrinkage during the formation of beryllium oxide ceramics using the hot casting method. The thermoplastic slurry is a composite system with a dispersion medium (binder) that has a very low thermal conductivity compared to the dispersed phase (beryllium oxide). Ultrasonic treatment reduces the viscosity of the slurry and improves its casting properties. The formation of beryllium oxide slurry is carried out without disrupting the integrity of the system and depends on the casting speed and temperature factors. The combined influence of these factors determines the casting properties of the slurry. Cooling - solidification of the slurry in the casting mold occurs in stages in the liquid, amorphous states with a phase transition, and in the viscoplastic state of the casting. The cooling rate of the casting at all stages depends on the cavity design, the rheological properties of the slurry, and the casting process parameters. It is important to maintain the integrity of the casting due to temperature shrinkage.

On the properties of cast and powder metallurgical Cu–6Ni-1.5Si-0.15Al (wt.%) alloy

In this study, Cu–6Ni-1.5Si-xAl (x = 0 and 0.15 wt%) alloys are manufactured as billet materials by casting and their metallurgical and physical properties are characterized. Aluminum modified alloy is obtained also by a powder metallurgical (PM) route and its structural properties are determined to be compared with the cast materials. The findings indicate that (i) solidified alloys have distributed nickel silicides (27.01 %) embedded in α-Cu(Ni,Si) solid solution, (ii) the addition of aluminum increases the amount of silicides (29.09 %) in the solidified matrix and reduces both the grain size and the secondary dendrite arm spacing, (iii) although PM alloy has similar microstructural features as cast alloys, it exhibits the highest hardness (159 HV1) due to both finer grain structure and better distribution of silicides, (iv) both impurity and porosity have a determining effect on the electrical conductivity (27–32 % IACS, International Annealed Copper Standard) values of the alloys.