Composite Casting Research Articles

Influence of WC-12Co reinforcement on sliding wear performance of stainless steel-based MMC processed in a microwave oven

The high hardness, corrosion resistance, excellent resistance to wear of WC-12Co, and good formability of nickel-based EWAC make these materials suitable candidates used as a reinforcement in stainless steel SS316 for manufacturing various automobiles and anti-wear parts. In this study, the composite castings of SS316+15% Ni-based (EWAC)+WC-12Co (5%–15%) have been developed by microwave hybrid heating. The tribological performance of cast composite samples has been assessed by a Pin-on-disc sliding wear tester. The behavior of cumulative weight loss, wear rate, and coefficient of friction of the cast surface at variable WC-12Co was investigated. The maximum cumulative weight loss, of 12.2 mg occurred at a 4 kg normal load and 1.5 m/s of sliding speed for 5%WC-12Co reinforcement. The minimum cumulative weight loss of 2.1 mg for the 15%WC-12Co at a speed of 1.0 m/s and a normal load of 2 kg. The 5.8 times anti-wear properties have been developed at 15%WC-12Co than 5%WC-12Co. The lower wear rate of 0.002 mg/s was observed at 0.5 m/s and a load of 2 kg. The delamination, shear, de-bonding of particles, pitting, formation of cavities, craters, plastic deformation, and smeared oxide layer were the causes of wear. The MMC microhardness was improved. The microstructure morphology was free from visual defects.

Use of alumina dispersant in alumina‐spinel castable: Comparison between in situ and preformed spinels

AbstractThe role of alumina dispersant as a flow modifier, completely replacing fume silica, on the properties of preformed and in situ spinel‐containing low cement high alumina castables was investigated with variations in spinel content and granulometry. Both 10 and 20 wt.% spinel‐containing compositions were prepared using preformed spinel or magnesia in alumina castable compositions with vibratable and self‐flowing consistency. The castables underwent conventional processing methods and accessed for various refractory‐related parameters post‐heat treatments. No glassy phase was observed in the castables upon firing. The presence of self‐flowing consistency led to improved characteristics. Preformed spinel‐containing compositions showed improved density, strength, hot strength, and thermal shock resistance properties, whereas slag corrosion and penetration resistances were found to be higher for in situ spinel‐containing castable.

Investigation of flexural performance of concrete beams with nonwoven/polymer composites versus steel-rebar reinforcement

The research investigates the unique characteristics and benefits of using nonwoven fabrics and polymer I cross-section composites in concrete beams. These materials show improved strength, flexibility, and corrosion resistance compared to conventional steel-reinforced beams, offering promising solutions for various construction applications. This study constructed an I-beam structure using a nonwoven polyester fabric/polyester composite cast in a concrete beam. Other designs included woven carbon fabric or Kevlar nonwoven fabric applied to the bottom flange of the I-beam for reinforcement. The flexural behavior of an I-beam polyester nonwoven/polyester composite with Kevlar or carbon-reinforced concrete beams was examined. The comparison between the different samples indicates that: flexural strength: the carbon sheet-reinforced sample exhibits the highest flexural strength, followed by the steel rebar and Kevlar-reinforced samples. The ductility: The steel rebar-reinforced sample shows the highest ductility, indicating better deformation capacity before failure. Carbon sheet reinforcement also provides substantial ductility. Bending stiffness: The highest bending stiffness is observed in the Kevlar-reinforced sample, suggesting a stiffer and less flexible beam. These observations highlight the trade-offs between stiffness, strength, and ductility in reinforced concrete beams. The reinforcement material choice depends on the application-specific requirements, such as the need for higher bending strength, better flexibility, or greater stiffness.

The Influence of Selected Laser Engraving Parameters on Surface Conditions of Hybrid Metal Matrix Composites.

Hybrid metal matrix composites (HMMCs) are a special type of material, possessing combined properties that belong to alloys and metals according to market demands. Therefore, they are used in different areas of industry and the properties of this type of material are useful in engineering applications, e.g., in aircraft engines and electrotechnical parts. The structure of the material requires a number of scientific studies to develop an appropriate processing technology. The paper presents the susceptibility of material from the HMMCs group with the EN AC-44300 (AISi12(Fe)) aluminum alloy matrix with a two-component reinforcement made of alumina particles (AP) and aluminosilicate fibers (AF) to thermal treatment with a laser beam. During this process, laser engraving of the researched material with variable beam power Pav and variable speed of the laser head vl were carried out. A metallographic analysis of the material was carried out. After laser engraving, surface structural changes of the material were determined. The properties of the surface geometric structure of processed material were also examined. Presented studies concern laser engraving on the surface of composite from the HMMC group, which was made by vacuum infiltration. Thanks to this method, it is possible both to produce shaped and precise composite castings with saturated reinforcement and to consequently minimize machining losses. Metal-ceramic composites from the HMMC group are hard-to-machine materials which create problems during machining. The aim of these studies was to develop a laser engraving technology with Al matrix composite with the addition of Al2O3 particles and aluminosilicate fibers, which constitute the reinforcement. The focus was on the selection of engraving parameters (beam power and speed of movement of the laser head). Clear examples of engraving, suitable for macro-assessment, were obtained with minimal change in the initial surface structure of the composite.

Preparation and properties of copper-aluminum composite strips and foils by horizontal continuous composite casting and rolling

Cu-Al composite strips and foils show broad application prospects in electric power, new energy and other fields. However, they are difficult to prepare because of brittle interfacial intermetallic compounds and deformation ability difference between two matrix metals. In this study, Cu-Al composite strips and foils with the thickness of 350 µm and 50 µm are successfully prepared by horizontal continuous composite casting and rolling. Moreover, the effects of as-cast interfacial layer thickness on the properties of Cu-Al composite strips are studied. In the rolling, the as-cast interfacial layer is broken into fragments, so as to promote the Cu-Al matrix bonding at atomic scale. The local solid-state amorphous transformation is also observed at the newly formed Cu-Al interface. Therefore, with the as-cast interfacial layer thickness decreasing from 400 µm to 25 µm, the peeling strength of Cu-Al composite strips increasing from 15.1 N/mm to 17.5 N/mm. With the as-cast interfacial layer thickness decreasing from 400 µm to 65 µm, the conductivity of Cu-Al composite strips increases from 62.36%IACS to 72.58%IACS because the size of interfacial layer fragments is reduced. However, with the as-cast interfacial layer thickness decreasing from 65 µm to 25 µm, the conductivity decreases from 72.58%IACS to 68.65%IACS because the copper layer thickness after rolling is reduced. Large interfacial layer fragments hinder current conduction, but a suitable interfacial layer thickness can inhibit the coordinated deformation of Cu and Al, so as to increase the proportion of copper layer thickness in the entire composite strip.

Parameter Optimization and Precision Control of Water-Soluble Support Cores for Hollow Composite Castings Fabricated by Slurry Microextrusion Direct Forming Method

Parameter Optimization and Precision Control of Water-Soluble Support Cores for Hollow Composite Castings Fabricated by Slurry Microextrusion Direct Forming Method

Determination of Saturation Conditions of the Aluminum Metal Matrix Composites Reinforced with Al2O3 Sinter.

Aluminum metal matrix composites (Al MMCs) are a class of materials characterized by being light in weight and high hardness. Due to these properties, Al MMCs have various applications in the automobile, aeronautical and marine industries. Ceramic-reinforced Al MMCs in the form of sinters are known for having excellent abrasive properties, which makes them an attractive material in certain fields of technology. The biggest problem in their production process is their low ability to infiltrate ceramics with alloys and consequently the difficulty of filling a ceramic preform. The castability of such composites has not yet been researched in detail. The aim of this study was to create aluminum metal matrix composite castings based on aluminum alloys (AlSi11) reinforced with an Al2O3 sinter preform using a Castability Trials spiral mold, and then to determine the degree of saturation with the liquid metal of the produced ceramic shaped body (Castability Trials spiral). For the selected AlSi11 alloy, the liquidus (Tl) and solidus (Ts) temperatures were determined by performing thermal-derivation analysis during cooling, which is Tl-579.3 °C and Ts-573.9 °C. The resultant pressure necessary for the infiltration process was estimated for the reinforcement capillaries with the following dimensions: 10, 15, 20, 25, 30 and 35 microns. The following values were used to determine the capillary pressure (Pk): surface tension of the alloy-σ = 840 mN/m; the extreme wetting angle of the reinforcement by the metal-θ = 136°. It has been experimentally confirmed that for the vacuum saturation process, the estimated resultant pressure enables saturation of reinforcement with capillaries larger than 25 microns, provided that the alloy temperature does not drop lower than the infiltration temperature. After the experiment, the time and route of the liquid metal flow in the spiral were determined. On the basis of the obtained values, a simulation was developed and initial assumptions such as saturation time, alloy temperature, reinforcement and mold temperature were verified. The energy balance showed that the saturation limit temperature was Tk = 580.7 °C for the reinforcement temperature of 575 °C. In contrast to the above, the assumption that the temperature of the metal after equalizing the temperature of the composite components must be higher than the liquidus temperature (Tliq = 579.3 °C) for the aluminum alloy used must be fulfilled. After the experiment, the time and path of the liquid metal flow in the spiral were determined. Then, on the basis of the obtained values, a simulation was developed, and the initial assumptions (saturation time and temperature) were verified.

Investigation of the role of impurities typical in secondary raw materials on the behaviour of high alumina castables - Part II: Influence on thermomechanical behaviour

The present work investigated the effect of relatively small additions of impurities originating in secondary raw materials on the thermomechanical properties of alumina castables bonded with active alumina. Castable compositions containing impurities for testing were selected on the basis of predictions from thermochemical calculations of their phase composition and the formation of large amounts of liquid phase at the temperature of 1600 °C. Viscosity of the emerging liquid phase was also calculated. The selected alumina castables with impurities from the systems: CaO–SiO2. Na2O–SiO2. Fe2O3–CaO. Fe2O3–CaO–SiO2 and TiO2–CaO–SiO2 were tested for thermomechanical properties by analysing the effect of impurities on refractoriness under load (RUL) creep in compression (CiC) and resonant frequencies and damping changes versus temperature (RFDA). Real composition of tested material via high temperature X-ray diffraction (HT-XRD) were verified. The obtained results indicate that impurities introduced into the refractory castables in a total amount of 0,18 wt% (2% in the fraction 0–45 μm) and in the most unfavourable ratio from the point of view of phase equilibria have an observable effect on the properties of the material at elevated temperature. The obtained results show that in the case of introducing impurities into the material with mutual proportions of shares limiting the formation of the liquid phase. It will be possible to maintain the thermomechanical properties of alumina castables at a satisfactory level (compared to the pure one) from the industrial process perspective in which it will be used. The obtained results shed new light on the possibilities of the conscious use of secondary raw materials in refractory monolithics technology.

Optimization of stir casting and drilling process parameters of hybrid composites

AA2219 alloy is widely used in aerospace and automobile applications, wherein the properties can be enhanced with 15% wt. of B4C reinforcement particles. Assembly task in aerospace application requires drilling millions of holes, and it is often challenging to obtain good-quality drilled holes due to the presence of hard B4C particle reinforcements. The self-lubricating capability of molybdenum disulfide (MoS2) and Graphene (Gr) materials was used as secondary reinforcements to improve the drilled hole quality characteristics. The stir-casting route fabricates the hybrid composites (AA2219 alloy/B4C/Gr/MoS2). The hardness and wear resistance properties of hybrid composites are affected by the influencing process variables such as percent reinforcement of Gr and MoS2, stirring speed, and pouring temperature. Taguchi L9 matrix is used for experimentation and performs statistical analysis. All stir-casting variables are found to make significant contributions toward hardness and wear resistance. The limitation of the Taguchi method to solve multiple objective optimizations is solved by applying Data Envelopment Analysis Ranking (DEAR) method. A DEAR method determined optimal conditions (Gr and MoS2: 1.5 wt%, stir speed: 400 rpm, and pouring temperature: 760 °C) resulted in a reduced wear rate of 1.65 × 10−3 mm3/min and 128 HV hardness in hybrid composites. The hybrid composites were prepared for the determined optimal stir casting conditions. Drilling experiments were carried out to analyze the variables such as feed rate (FR), drilling speed (DS), and drill tool material (DM): high-speed steel: HSS, carbide: C, and coated carbide: CC that affect the hybrid composite hole quality characteristics such as burr height: BH, material removal rate: MRR, and thrust force: TF. A DEAR method determined optimal drilling conditions (FR: 0.25 mm/rev; DS: 20 m/min; DM: coated carbide drill tool) resulted in 645 mm3/min of MRR, 2.95 kN for TF, and 0.16 mm for BH, respectively. The self-lubricating capability of Gr and MoS2 reinforcement particles in hybrid composites ensures excellent composite properties and drilled-hole quality characteristics. Taguchi and DEAR methods employ simple mathematical steps which can be used by novice industry personnel to perform optimization for other output characteristics.

Manufacturing of Composite Castings by the Method of Fused Models Reinforced with Carbon Fibers Based on the Aluminum Matrix

Manufacturing of Composite Castings by the Method of Fused Models Reinforced with Carbon Fibers Based on the Aluminum Matrix

Manufacture of Composite Cast Blanks Using Steel and Cast-Iron Elements

Manufacture of Composite Cast Blanks Using Steel and Cast-Iron Elements

Investigation of the milling route for the development of colloidal suspensions to be used as binder in refractory castables

Refractories castables bonded with CAC (calcium aluminate cement) have a limitation when they are used at high temperature in micro-silica containing system and/or in acidic corrosive environments. The CAC binder reacts with the micro-silica and/or acidic components to form liquid/viscous compounds deteriorating the refractory material.Refractory castables bonded with HA (hydratable alumina) perform better in these environments. However, the drying step of such materials needs time and energy for the water evacuation to avoid the lining cracking.The use of CS (colloidal silica) as binder seems to hinder the drawback of CAC and HA binders. However, the presence of free amorphous silica in the castable composition limits their uses in basic environments by forming liquid/viscous phases at high temperature with a reduction of castable refractoriness.In this context, new colloidal bonding systems that could improve the high performances of refractory castables such as boehmite and spinel colloidal suspensions, were developed.

Development of iron-based composite materials through electromagnetic radiations in a domestic microwave oven

Microwave hybrid heating, a novel technique, is used to develop iron-based alloy (SS316), SS316+10EWAC1004 (nickel-based), and SS316+10EWAC1004+5Cr7C3 composite castings. The domestic microwave having a frequency of 2.45 × 103 MHz and a power of 0.9 kW, is used with a variable exposure time of microwave radiations. The microwave interaction procedure with the metallic powder is discussed to optimize the exposure time and temperature. A microstructure study of developed castings revealed the uniform melting of matrix and EWAC1004 with an identical dispersion of Cr7C3. The X-ray diffraction results revealed various intermetallic (Ni3Fe, Ni2Si, Cr2Ni3, MoNi4, Fe3Si, Fe2Si, CrFeNi) and hard carbides (Fe3C, Cr3C2, Cr23C6) phases. The maximum average micro-hardness is for the SS316+10EWAC1004+5Cr7C3 composite, followed by SS316+10EWAC1004. The established composite casting had a hardness of around 2 times that of the commercial SS316. The maximum density of 97% was found for Iron-based SS316-based. The grain size of microwave-processed SS316, SS316+10EWAC, and SS316+10EWAC +5Cr7C3 specimens is found to be 21 ± 4 µm, 18 ± 3 µm, and 17 ± 2 µm, respectively. It has been observed that reinforced phases hinder grain growth, and hence grain size reduces significantly. In comparison, commercial SS316 had a grain size of 31 ± 6 µm. The ASTM B-276 standard is used to determine pores that are of the order of 1.98%.

Influence of tungsten carbide-cobalt reinforcement on flexural behavior of iron-based composite developed through microwave

The flexural behavior of iron-based composite castings has been analyzed under three-point loading conditions. The metal matrix composite casting of five varying compositions of powders by weight, that is, SS316, SS316+15EWAC, SS316+15EWAC+5WC−12Co, SS316+15EWAC+10WC−12Co, and SS316+15EWAC+15WC−12Co has been cast in a domestic microwave oven of maximum power and frequency of 0.9 kW and 2.45 × 103 MHz respectively. The casting of size 30 × 6 mm2 is prepared. The prepared sample’s mechanical properties, such as ultimate peak load, flexural strength, strain at peak load, strain at break and flexural modulus, are tested on Dak System UTM having load cell 10 kN as per ASTM 1161-18 standard. The flexural strength and peak load for SS316+15EWAC+10WC−12Co, strain at peak load for SS316+15EWAC+5WC−12Co, and flexural modulus and microhardness for SS316+15EWAC+15WC−12Co were found maximum value. The maximum microhardness value is obtained in the carbide phase. The microstructure of the cast samples shows equiaxed grain growth with identical melting of the matrix. The XRD pattern of the samples confirmed the presence of various intermetallic and carbide phases.

Nb Phase Position Marking for Clarifying the Formation Process of Cu-Al Composite Interfacial Phases in Continuous Composite Casting

Cu-Al composites are widely applied materials exhibiting advanced properties of both matrix metals. Controlling the brittle interfacial phases is a key factor in improving the interfacial strength of Cu-Al composites. This paper studied the interfacial formation process of Cu-Al composites fabricated by continuous composite casting. The phase formation sequence, growth direction and formation mechanism were clarified via element marking and thermodynamic calculations. The spatial distribution of the interfacial phases from the aluminum side to the copper side is as follows: the α + θ layer (α-Al + CuAl2), the θ layer (CuAl2) and the γ layer (Cu9Al4). Moreover, insular η phases (CuAl) and δ phases (Cu3Al2) exist in the γ phase sublayer. The formation sequence of interfacial phases is as follows: the θ phase, the η phase, the δ phase and the γ phase. The θ layer and α + θ layer are transformed from a liquid diffusion layer formed by scouring the surface of copper with liquid aluminum, the η and δ phases grow towards the θ layer and the γ phase simultaneously grows towards both the copper matrix and the θ layer.

Gradient-distributed ZTAp-VCp/Fe45 as new anti-wear composite material and its bonding properties during composite casting

Abstract In this article, gradient-distributed VCp-ZTAp/Fe45 composites were prepared by vacuum sintering, and three-body abrasive wear experiments were carried out to investigate its anti-wear performance. The composite casting of VCp-ZTAp/Fe45 was investigated by using the finite element method and experiments, and the bonding between the Fe45 substrate and 35SiMnCrMoNi steel was fully investigated. Results show the in situ formation of VCp in the VCp-ZTAp/Fe45 composite matrix during vacuum sintering. The anti-wear property of the VCp-ZTAp/Fe45 composite is ca. 7 times that of Hardox450 and NM450 and ca. 8 times of 30SiMn. There forms a solid metallurgical bonding between the Fe45 matrix of VCp-ZTAp/Fe45 and 35SiMnCrMoNi steel, with a ca. 80 μm thickness of the bonding area during the composite casting.

Elimination of Carbides in Carburized Layer of Stainless Steel/Carbon Steel by Horizontal Continuous Liquid-Solid Composite Casting.

The carbides in the carburized layer of stainless steel (SS)/carbon steel (CS) clad plates are prone to inducing intergranular cracks and reducing the interfacial bonding strength. In this paper, SS/CS clad plates were fabricated by horizontal continuous liquid-solid composite casting (HCLSCC), and the formation mechanism of the interfacial carbides and their effect on the elimination of carbides in the carburized layer were revealed by numerical simulation and thermodynamic calculations. During the HCLSCC process, the cladding interface encountered re-melting and re-solidification after rapid melting and solidification, resulting in liquid-liquid and solid-solid diffusion at the cladding interface, where the atomic ratio of Cr/C (Cr/C) gradually increased. Therefore, strip M7C3 and M23C6 carbides as well as blocky M23C6 carbides formed at the cladding interface in turn and had a coherent relationship with the matrix. The blocky M23C6 carbides led to an increase of 240% in the interfacial ferrite strength. The formation of interfacial carbides reduced the difference in C activity between the cladding interface and SS, thus preventing the diffusion of C to SS and inhibiting carbide precipitation in the carburized layer of SS, which was beneficial to improving the interfacial bonding strength.

Analysis of liquid–solid interface bonding behaviour of 7075 aluminium alloy/SiCp reinforced aluminium base alloy

The introduction of heterogeneous elements and the presence of the oxide layer on the surface of aluminum alloy usually play a negative role in the interfacial bonding of Al/Al bimetallic composites. To solve these two key problems of interfacial bonding of bimetallic composites. This work proposes to composite SiCp/7075(solid)-7075 alloy(liquid). The main alloying element Zn of 7075 alloy is selected to perform hot dip treatment on SiCp/7075(solid) to reduce the influence of the oxide layer on the surface of the aluminum alloy and the introduction of heterogeneous elements. Al/Al bimetallic composites were prepared by using a hot-dip/non-hot-dip zinc + liquid–solid composite casting process. The bimetallic composite interfacial bonding of SiCp/7075–7075 matrix alloy was studied. The results revealed that an oxide layer existed at the interface of the bimetallic composite upon preheating at 400–475 °C and hot dipping at 400–425 °C. With an increase in the hot-dip temperature, the interface oxide layer disappeared because of the combined effect of thermal expansion deformation, lower solidus temperature of the zinc-rich layer, and volume expansion of the solid–liquid phase transition. Metallurgically bonded interfaces were obtained at the hot-dip temperatures of 450 and 475 °C. The fracture location was on the SiCp/7075 Al matrix composite side, showing that this composite's interfacial bond strength was higher than that of the SiCp/7075 Al matrix composites. The results of this study provide a new idea for the preparation of lightweight wear-resistant Al/Al bimetallic composites by liquid-solid composite casting.

Feasibility Study on the Fabricating of Carbon-Nanotube-Reinforced Al-Si-Cu Alloy Matrix Composites Using Oxygen-Replacing Die Casting Process

A383 Al-Si-Cu alloy matrix composites were reinforced with different amounts (0.5, 1.0, 1.5 and 2.0 wt%) of chopped multiwalled carbon nanotubes (MWCNTs) and fabricated using the oxygen-replacing die casting (ORDC) process to reduce gas porosities via the reaction of molten Al and O2 replaced in the mold cavity. MWCNTs were added to the mold cavity by supplying O2 and using a poly gate in the ORDC mold to improve CNT dispersity in the matrix of the composite. Microstructure studies of the composites showed a uniform CNT distribution within the matrix and grain refinement. X-ray computed tomography images showed that the internal porosities were affected by the CNT addition amount and gate type used in the mold, and Raman spectroscopy analysis indicated that CNTs in the matrix were free of significant defects. The 1.0 wt% CNT-added composite cast using the poly gate showed the highest ultimate tensile strength of 258.5 ± 5.2 MPa and hardness of 157.9 ± 3.0 Hv; these values were, respectively, 21% and 30% higher than those of the monolithic A383 alloy, confirming the feasibility of fabricating the MWCNT-added A383 alloy composite with a poly gate using the ORDC process.

Simultaneously enhanced strength-ductility synergy and corrosion resistance in liquid-solid bonded stainless steel cladding carbon steel plate by hot rolling and annealing treatment

Liquid-solid (L-S) bonded stainless steel/carbon steel (SS/CS) laminated composites have strong metallurgical bonding interface, while the solidification structure of SS deteriorates the mechanical properties and corrosion resistance. In this study, hot rolling and annealing were proposed to regulate the microstructures and balance the performance of L-S bonded SS/CS clad plates. SS cladding CS plates were prepared by horizontal continuous liquid-solid composite casting and hot rolled at 1200 °C with a reduction rate of 90%, and annealed at 1000 and 1050 °C for 30 min. The microstructural evolution was studied by scanning electron microscope and electron back-scatter diffraction, elemental distribution was investigated by electron probe microanalysis. Microhardness, tensile test and anodic-cathodic polarization test in a 3.5% NaCl solution were carried out on hot-rolled and annealed SS cladding CS plates, and the mechanism for the simultaneous enhancement of strength-ductility synergy and corrosion resistance by hot rolling and annealing was analyzed. Annealing at 1050 °C resulted in excellent properties with tensile strength of 550 MPa and elongation of 50%, corrosion potential of −0.21 V and corrosion current density of 0.13 μA cm−2. The strength and ductility of the SS cladding CS plate were synergistically improved by a strong metallurgical bonding cladding interface, high frequency of low-Σ CSLs and refinement of grains in 304 SS. The low-Σ CSLs in 304 SS restricted the formation of carbides in the carburized layer and broke down the connectivity of random boundaries, improving the corrosion resistance.