Centrifugal Casting Method Research Articles

CHARACTERIZATION OF CENTRIFUGAL CASTING METHOD FOR PULLEY MANUFACTURING USING VARIABLE ROTATIONAL SPEED

Due to advancements in the industrial sector, aluminum is progressively gaining popularity as a material of choice in the field of engineering. A pulley is a component that functions as a link or transfers power or engine rotation to the load via the V-belt belt. This study aims to determine the characterization of aluminum material made by the centrifugal casting method from used brake shoes with rotational speed variables of 0 RPM, 100 RPM, and 200 RPM. The characterization of the casting results in this study was analyzed using the Brinell hardness test and the Charpy impact test. The results of the Brinell hardness test showed that aluminum castings for making pulleys with an additional 100 RPM die rotation speed had a Brinell hardness value of 53.22 BHN. The results of the impact test with the Charpy method showed that specimens with a mold rotation speed of 100 RPM had an impact value of 0.0135 kg.m/mm2. The results of this study concluded that variations in rotational speed of 100 RPM in the casting of pulleys made of used aluminum using the centrifugal casting method can produce products that have good toughness.

Ceramic-metal pipes with NiAl2O4 and TiAl2O5 spinel phases with different metallic phase content - Analysis of properties, and microstructure, taking into account LCA

The article describes the formation of samples into pipes with NiAl2O4 and TiAl2O5 spinel phases with different metallic phase content. The centrifugal slip casting method was used to form the composites. All suspensions used were shear thinning and were characterized by slight thixotropy. The analysis of the phase composition and chemical composition showed the presence of Al2O3, TiAl2O5 and NiAl2O4 in the produced samples. The produced materials were characterized by brittle fracture behaviour. The obtained life cycle assessment results clearly showed that as the content of the metallic phase increases, the environmental footprint of sinters in the A1 phase increases, which is a direct consequence of the increased use of raw materials.

Mechanical properties of functionally graded Al series 3000 with addition of Li 2.3 wt%

ABSTRACT One of the effective methods in increasing the device performance is the use of components made of new and advanced materials, and their physical and mechanical properties are in opposition and often lightweight. In the present study, a functionally graded (FG) pipe Al series 3000 with addition of Li 2.3 wt% fabricated by using horizontal centrifugal casting method at pouring temperature of 750°C and final round of mould of 1000 rpm (mould preheated up to 150°C). The evaluation of microstructure, hardness, compressive strength and wear resistance was done by using VEGA2 SEM, Vickers hardness test at 50 g force, Zwick Z100 test machine and pin on disc under a stress of 7.6 MPa in a distance of 1000 m, respectively. The results indicated a graded manner in the content of Li, Si and Cu from outer to inner layers of FG pipe with a density of 2.4 g cm–1. The sum of intermatallic phases in the matrix, such as β (AlLi), AlSi and Al2Cu, increased from 17 Vol% to 35 Vol%. Therefore, the hardness and ultimate compression strength of the outer layer graded in comparison to the inner layers. Also, the wear resistance of the inner layer increased 18% in comparison to that of the outer layer.

The influence of Ti/Ni metallic phase content on the microstructure and environmental interactions of gradient Al2O3-based composites

Al2O3/Ti/Ni composites, enhanced with the inclusion of NiAl2O4 and TiAl2O5 phases, represent a novel class of advanced materials with multifaceted properties suitable for diverse engineering applications. Centrifugal slip casting method was used for preparation of two series of gradient Al2O3/Ti/Ni composite samples with different content of the metallic Ti and Ni phases. Series I containing 0.5 vol.% of Ni and 0.5 vol.% of Ti and Series II containing 2.5 vol.% of Ni and 2.5 vol.% of Ti. Each series contained 55 vol.% of a solid phase. Rheological properties of the suspensions as well as microstructure of the obtained composites were studied, with special attention paid to the analysis of the formed spinel phases. Both series in the green form were characterized by 3-zone structure with different metallic phase content. The widths of individual zones for the Series I and Series II, after sintering at 1450?C, were 0.53mm (zone I), 3.26mm (zone II), 0.8mm (zone III) and 1.27mm (zone I), 1.47mm (zone II), 1.87mm (zone III), respectively. The results showed that after sintering two spinel phases were formed. The NiAl2O4 spinel phase consists only of small grains with a size of approximately 1.3- 1.8 ?m, which form larger clusters with or without a void inside. The TiAl2O5 phase consists of grains with an average size of 4.3 to 4.5 ?m. The Life Cycle Assessment analysis revealed that the values of the global warming potential indicator in phase A1 are 0.16 kg and 0.20 kg equivalent of CO2 per sintered sample for the Series I and Series II, respectively.

Numerical Simulation on Solidification during Vertical Centrifugal Casting Process for TC4 Alloy Wheel Hub with Enhanced Mechanical Properties.

The Ti-6Al-4V (TC4) alloy wheel hub has exhibited some defects that affect the properties during the vertical centrifugal casting process. Therefore, the analysis of the solidification process would contribute to solving the above-mentioned problems. In this study, an orthogonal experimental design was employed to optimize the process parameters (rotational speed, mold preheating temperature, and pouring temperature) of the vertical centrifugal casting method. The effects of process parameters on the velocity field, temperature field, and total shrinkage porosity during the solidification process were explored, and the microstructure and mechanical properties of the wheel hub prepared by the vertical centrifugal casting method were also investigated. The results showed that the rotational speed mainly induced the change of the velocity field. The pouring temperature and mold preheating temperature affected the temperature field and solidification time. Based on the analysis of the orthogonal experiment, the optimal parameters were confirmed as a rotational speed of 225 rpm, mold preheating temperature of 400 °C, and pouring temperature of 1750 °C, respectively. The simulation results of total shrinkage porosity were in agreement with the experiment results. The wheel hub was composed of nonuniform α and β phases. The lath α phase precipitated from larger β grains with different orientations. Compared with the other samples at different locations, the α phase in the PM sample (middle of the TC4 wheel hub) displayed high peak intensity and uniformly distributed β phase along the radial direction of the wheel hub. Moreover, the PM sample revealed a higher tensile strength of 820 MPa and similar Vickers hardness of 318 HV compared with the other samples at different locations, which were higher than those of rolling and extrusion molding. This experiment design would provide a good reference for the vertical centrifugal casting of the TC4 alloy.

Investigating wear behavior of Al/Al2O3/Gr hybrid composite prepared by centrifugal casting method

Investigating wear behavior of Al/Al2O3/Gr hybrid composite prepared by centrifugal casting method

Experimental Investigation of the Mechanical and Structural Properties of a Functionally Graded Material by Adding Alumina Nanoparticles Using A Centrifugal Technique

In this work, functionally graded materials were synthesized by centrifugal technique at different volume fractions 0.5, 1, 1.5, and 2% Vf with a rotation speed of 1200 rpm and a constant rotation time, T = 6 min . The mechanical properties were characterized to study the graded and non-graded nanocomposites and the pure epoxy material. The mechanical tests showed that graded and non-graded added alumina (Al2O3) nanoparticles enhanced the effect more than pure epoxy. The maximum difference in impact strength occurred at (FGM), which was loaded from the rich side of the nano-alumina where the maximum value wasat 1% Vf by 133.33% of the sample epoxy side. The flexural strength and Young modulus of the functionally graded samples were enhanced by 43.69% and 52.74%, respectively, if loaded from the alumina-rich side. On the other hand, when loading (FGM) from the epoxy side, the amount of decrease in bending resistance was 122.4% while the improvement in bending modulus was 81.11% compared to pure epoxy. Scanning electron microscopy (SEM) revealed the fracture surface of the impact samples and the gradient scattering of nanoparticles in the epoxy matrix. Numerous applications can be used to manufacture the functionally graded material by centrifugal casting method, including for the manufacture of gears and all bending applications such as leaf springs.

Hierarchical membrane by centrifugal casting and effects of incorporating activated carbon as pore-former

Producing ceramic asymmetric membranes usually requires several steps to prepare macroporous support and then the selective layer deposition. This process is energy and time-consuming, which is expensive. In this sense, the one-step centrifugal casting technique is an interesting alternative. Therefore, this work aimed to prepare ultrafiltration ceramic membranes by the centrifugal casting method, investigating the effect of a pore-forming agent on membrane performance. Different concentrations of activated carbon were used in the alumina suspension, and then the tubes were molded, dried, and sintered. The membranes' shrinkage, morphology, apparent porosity, hydraulic permeance, and BSA protein retention were evaluated to identify the effect of using the pore-forming agent. The membrane prepared without activated carbon rejected 91% of the BSA molecules (66 kDa), indicating its molecular weight cut-off. Using more than 2.5% of activated carbon increased the porosity and hydraulic permeance of the membranes, but at the expense of low BSA retention.

Effect of Re addition on the microstructure and mechanical properties of AlCoCrFeNi2.1 eutectic high-entropy alloy

Alloying is an important and effectivise means to realize mechanical properties improvement of alloys and HEAs. In this article, series of (AlCoCrFeNi2.1)100-xRex high entropy alloys, where x = 0, 0.3, 0.6 and 1 (wt.%), were prepared using a centrifugal casting method, and the effect of Re content on the phase composition, microstructure and mechanical properties was investigated. With Re addition increase, the NiAl-enriched phases in the base alloy decreased or even disappeared, and the lamellar spacing of eutectic phases decreased. Moreover, FeCoCr-enriched primary dendrite phases emerged in the alloy system after Re addition and its volume increased dramaticly when Re addition increased to 1 wt%. The reason for this phenomenon is that the addition of trace Re element makes the shift of eutectic composition point to hypereutectic composition point. Additionally, both yield stress and ultimate tensile stress were increased with Re addition, but the elongation decreased.

Optimization of process parameters for centrifugal cast single point cutting tools using Grey-Taguchi technique

Single point cutting tool has been developed by using the centrifugal casting method. The performance of the cutting tool has been evaluated by employing Grey-Taguchi multi-objective optimization technique for a better-optimized result during the finish turning of MS workpiece. Cutting velocity, feed, and depth of cut were taken as the cutting parameters. Based on the optimization technique, optimum cutting parameters were found out for both wear at flank surface and surface roughness minimization. ANOVA analysis suggested feed with maximum contribution of 40.57% for minimizing surface roughness. Similarly, cutting velocity was found to have maximum contribution of 87.67% for minimizing flank wear. Also, cutting velocity was observed as the important process parameter which affected both the responses.

Mechanical, chemical, metallurgical characteristics under HBSS solution and optimization of AZ91D-Ti functional graded composites using TOPSIS

ABSTRACT. Functional graded magnesium matrix composites (FGMMCs) are widely employed for biomedical, aerospace and thermal barrier applications because of their better mechanical properties, biocompatibility and bioactivity. In this study, AZ91D-wt. %Ti (x = 0, 4, 8, 12 and 16) composites are fabricated by ex-situ centrifugal casting method. The NaCl based solution is sprayed on all fabricated magnesium composites for 72 hours at the 1 kg/cm3 pressure spray and 6.9 pH value in salt spray chamber. The microhardness and flexural strength of fabricated composites are determined. The corrosion resistance of AZ91D-wt. %Ti fabricated composites is determined for 21 days immersion. The AZ91D -12wt. %Ti exhibits higher microhardness, flexural strength and corrosion resistance than other produced AZ91D-Ti composites. The optimization on micro machining process parameters is done on the AZ91D-12wt. %Ti with the help of Technique for order of preference by similarity to ideal solution (TOPSIS).The input process parameters are selected as cutting rate, feed rate, depth of cut and tool type and the response parameters are selected as feed force, normal force, tool wear rate, burr height and surface roughness. The computed optimal micro milling process parameters are at 120 m/min cutting speed, 0.5 µm feed rate, 0.15 mm depth of cut and the TiB2 coated tool.
 
 KEY WORDS: AZ91D -Ti, TOPSIS, Surface roughness, Tool wear loss, Cutting force
 
 Bull. Chem. Soc. Ethiop. 2023, 37(1), 77-89. 
 DOI: https://dx.doi.org/10.4314/bcse.v37i1.7

Utilization of machining chips waste for production of functionally gradient magnesium matrix composites

In this study, lightweight functionally gradient materials (FGMs) with graded behavior were produced utilizing AZ91D magnesium chips reinforced with boron carbide particles through a centrifugal casting method. Innovatively, the influence of reuse magnesium chips generated during machining processes on the gradient formation and mechanical characteristics of graded composites was investigated. Also, the effect of strengthening mechanisms on graded composites was deeply explored. The results showed a considerable improvement in particle distribution inside the matrix, owing mostly to a pre-mixing technique for chips and particles before melting during the preparation steps. The study also found that due to the higher particle concentration, the mechanical characteristics of the graded composite were much better in the outer region than in the transition and inner regions. As a result of the microstructure gradient, the tensile strength of the graded composites increased from 164 MPa to 210 MPa (at the outer zone), the compressive strength increased from 312 MPa to 339 MPa (at the outer zone), and the hardness increased from 63.7 HV to 110.8 HV (at the outer zone). Additionally, the findings reveal that the theoretical values are in good agreement with the experimental values of the concentration of B4C particles within the AZ91D matrix alloy. The above research work can provide a new perspective on using magnesium chips as a matrix material reinforced with ceramic particles for fabricating gradient composites, hence promoting potential applications.

Comprehensive analysis of the microstructure, properties and environmental performance of Al2O3-ZrO2 composites obtained via centrifugal slip casting

This research investigates the possibility of preparing Al2O3-ZrO2 composites with different proportions of the Al2O3 and ZrO2 phases by centrifugal slip casting (CSC) method and the effect of the solid phase content (50 vol%, 45 vol%, 40 vol%) on the microstructure and selected properties of the produced materials. The hardness results showed that all the series produced were characterised by high hardness, in the range of 16–19 GPa. The results of the static compression test demonstrated that increasing the solid phase content of the slip in the samples promotes the formation of fewer cracks during the monotonic compression loading of the composites. The LCA results demonstrated that as the content of ZrO2 in the composites increase, their environmental footprint increases.

Understanding centrifugal casting in the manufacture of functionally graded materials

Centrifugal casting is a shaping technique intended for ceramic tubular structure manufacture, where the particle size and density are exploited to produce asymmetrical membranes and functionally graded materials. However, some well-established insights about particle segregation are debatable and remain unclear. For instance, small particles do not necessarily stay in the inner region, and the bigger particles do not accumulate in the outer. Herein several manufacturing parameters were studied through Taguchi’s robust design, using discrete element method-based simulations to generate the data. Alumina powder was used as model material and water as the liquid phase, to assess the green cast formation time, the cast thickness, the roundness, the changes in relative density, and particle size distribution along the cast’s cross-section. The mean particle diameter and the rotation speed are the most influential parameters for the casting time. The volume fraction of solids on the precursor slurry is decisive regarding the cast structural properties, and particle segregation is negligible, except for size differences above one order of magnitude. When a fraction of denser nickel powder was added, density segregation was also observed, but the size differences can overshadow its effect. In addition, alumina and nickel particles were cast in a lab-scale centrifuge and experimentally validated the segregation of particles. The centrifugal casting method was successfully applied for producing the Al2O3-Ni composites with a gradient distribution of the Ni phase.

Fabrication of Highly Transparent Y2O3 Ceramics via Colloidal Processing Using ZrO2-Coated Y2O3 Nanoparticles

An easy approach is described for the preparation of ZrO2-coated Y2O3 nanopowder from a solution of zirconium nitrate with commercial Y2O3 nanopowder. The evolution process of the ZrO2 coating layer upon calcination, such as the phase and microstructure of the particles’ surface, was studied. Calcination of the powder at 700 °C resulted in ZrO2-coated Y2O3 nanopowder. The rheological properties of the suspensions of ZrO2-coated Y2O3 powders were studied. A well-dispersed suspension with a solid loading of 35.0 vol% using ZrO2-coated Y2O3 nanopowder was obtained. The consolidated green body obtained by the centrifugal casting method showed improved homogeneity with a relative density of 50.2%. Transparent ceramic with high transparency and an average grain size of 1.7 µm was obtained by presintering at 1500 °C for 16 h in air, followed by post-HIP at 1550 °C for 2 h under 200 MPa pressure. The in-line transmittance at the wavelength of 1100 nm (1.0 mm thick) reached 81.4%, close to the theoretical transmittance of Y2O3 crystal.

Grain size, carbide distribution and hardness issues pertaining to cutting tools produced from high speed steel scraps

ABSTRACT Single point cutting tool blanks are prepared adopting the centrifugal casting method using only scrapped high-speed steel tools collected from different installations for better mechanical properties and economical production. The cast cylindrical blanks are cut into shapes by wire-cut EDM and subsequently heat-treated. Upon heat treatment, the centrifugal cast tool exhibited a reduction of grain size about 60% accompanied by about 22.7% increase in the hardness. The conventional cast HSS M2 tools procured from the market are compared with centrifugal cast tools. SEM images of both tools showed two different eutectic carbide patterns. Also, the precipitation of M6C and MC carbides are found in XRD analysis for both tools. Upon EDX analysis, W, V, and Cr are found to be the prime elements responsible for carbide formation. Wear characteristics of centrifugal cast tool observed are as par with the HSS M2 tool during turning of mild steel (ASTM A36) under identical environment. This method will be helpful for the development of cutting tools for industrial applications.

Properties of Al2O3/Ti/Ni composites fabricated via centrifugal slip casting under environmentally assessed conditions as a step toward climate-neutral society

The paper concerns functionally graded composites obtained by centrifugal slip casting method. Al2O3, Ni, Ti, differed is size and morphology, were used as starting powders. The influence of metallic phase content (2 vol% and 20 vol%) and homogenisation process (planetary-ball milling) on suspension viscosity as well as density, phase composition, microstructure and mechanical properties of sintered bodies was investigated. Planetary-ball milling decrease the viscosity of suspensions of lower metallic content due to increase of their homogeneity. Slurries of higher metallic content, after homogenisation process, exhibit higher viscosity due to refinement of large metallic particles which leads to more intense surface interactions. CSC was applied to shape samples in form of thick-wall tubes with gradient microstructure across the wall thickness. Relative densities, after sintering, were about 10% higher for the samples containing 2 vol% of metallic phase (99.40% and 98.42%) compared to specimens of higher metallic content (90.57% and 86.86%), regardless of homogenisation process. Planetary ball milling had a positive effect on microstructure of obtained graded composites, leading to more homogeneous microstructure with well defined zones and lower number of defects, in both types of sample (2 vol% and 20 vol% of metallic content). Higher content of Ti and Ni caused that metal-rich zone was thicker, but microstructure was more defected. Hardness was higher for samples of more homogeneous microstructure. XRD confirmed the presence of Al2O3 and Ni, Ti phases but also evinced occurrence additional intermetallic phases form Ni–Ti system. The environmental impact accompanying fabrication of composites was evaluated using the LCA method. It was done in order to determine burdens caused at the early beginning of the research and development stage, creating a reliable basis for further development of an environmentally friendly industrial process, simultaneously being a step toward transition to a climate-neutral society which is one of the main objectives of European Green Deal.

PREDIKSI SISA UMUR PAKAI TUBE REFORMER JENIS HP MODIFIED

ABSTRACT
 Tube reformer modified HP type (23Cr-35Ni Nb) is an important component in the fertilizer industry in the primary reformer. Tube reformer is produced in centrifugal casting method that has the hard characteristic, put up with high temperature, pressure and resistance corrosion. It is because it has a large amount of nickel (Ni) and chrome (Cr) elements so that it can hamper the corrosion. The tube reformer has been operated on for 15 years. Based on technical data modified HP tube reformer has 11,4 years of design life and one of the tubes had been burst in beneath, so it needs to decide how long the remaining life assessment of the modified HP reformer tube is. The aim of the research is in order to know how to last long the remaining life assessment of the tube reformer HP modified used, so it can plan to fix/change with a new tube. In order to support the research, it needs some tests such as metallography, hardness test, tensile test, chemical composition, and creep test. According to API 530, to measure how last the remaining life assessment of tube reformer based on creep test which is accelerated by using LMP method can get 52488,35 hours or 5,99 years. The remaining life based on microstructure damage related to the classification diagram of tube wall damage according to L May in C level (or 50 %) is 50,000 hours or 5,77 years.
 Keywords: Centrifugal casting, tube reformer HP modified, creep test, Larson Miller parameter, remaining life assessment.

Dendrite‐Free Lithium Deposition and Stripping Regulated by Aligned Microchannels for Stable Lithium Metal Batteries

AbstractLi metal is the ultimate choice for the anode in next‐generation high energy density rechargeable batteries. However, undesired dendrite growth, dead Li formation, and a large volume change of the lithium metal anode lead to severe safety hazards such as short‐circuiting, fire, or even explosion. Graphene oxide (GO) in large areas has been prepared as the Li metal host via a continuous centrifugal casting method. Aligned microchannels are then fabricated in it by a simple punching method using 3D printed templates. The GO matrix effectively regulates the lithium plating/stripping behavior while the aligned channels uniformly distributes the Li‐ion flux and provides short Li‐ion diffusion paths. The Li/ holey GO composite is flexible with a controllable thickness from 50 to 150 µm, which corresponds to capacities from 9.881 to 27.601 mAh cm−2. As a result, the anode has a low overpotential of 30 mV after 100 h, a high capacity of ≈3538 mAh g−1 (91.4% of the theoretical capacity), and a superior rate ability of up to 50 C with a LiFePO4 cathode. The holey GO/Li electrode is also paired with other cathodes and used in pouch cells, indicating its suitability for various high‐energy battery systems.

Sustainable ZTA composites produced by an advanced centrifugal slip casting method

The centrifugal slip casting method presented in the paper is used to form ceramic sleeves with a good shape representation, eliminating material losses in machining or other forms of mechanical treatment that could be necessary when other moulding methods with a poorer shape representation are used. Sleeves developed this way can be used as system components to transport aggressive substances under elevated pressure and temperature conditions. To confirm the functionality of the sleeves prepared with the method, Al2O3, ZrO2, and composite components of ZTA were characterised for acid-base behavior, phase composition, microstructure, and mechanical strength. The tests confirmed the formation of expected gradient structures for ZTA composites. It results in the generation of components with improved flexural and torsional strength compared to non-gradient ZTA composites with the same Al2O3 to ZrO2 ratio. Applying a smaller quantity of ZrO2 should bring a positive economic effect, considering its high price. The analysis of accompanying environmental impacts was carried out for developed materials along with the lifecycle analysis. The paper describes a reduced waste generation method for making components for aggressive substance transportation systems. The present paper presents characteristics of materials for their resistance to factors under working conditions, demonstrating their durability and potential to reduce waste related to the operation of such system types.