Powder Processing Method Research Articles

Binder jet 3D printing of Mn–Zn ferrite soft magnet toroidal cores

Traditional powder processing methods for Mn–Zn ferrites limits design freedom and scalability of producing customized soft magnetic cores. In this work, binder jet 3D printing techniques were applied to commercially available Mn–Zn ferrite powders and toroidal cores were successfully fabricated. As-printed Mn–Zn ferrite powders were sintered at different temperatures between 1300 and 1400 °C, resulted in an optimized single-phase spinel at 1350 °C. Microstructural characterization revealed high porosity remained for binder jetted materials and various magnetic property measurements were performed on sintered cores. Despite high porosity, the saturation moments normalized by mass remained similar between binder jetted and traditionally compacted samples. Two-winding method measurements indicated a large demagnetizing field for binder jetted samples. Effective medium theory model was used to estimate the effect of remnant porosity on measured magnetic permeabilities. Importance of novel concepts to successfully realize dense cores through additive manufacturing pathways such as binder jetting is highlighted.

Advanced Bioceramics: Properties, Fabrication and Applications

Bioceramics are engineered materials that achieve their applications in the medical field. Bioceramics are promising inorganic materials to create scaffolds for bone regeneration due to their desirable properties, such as biocompatibility, osteoconduction, and their similarity with bone composition. Bioceramics can operate as tissue replacement and can be used for coating metal implants to increase their biocompatibility. Bioceramics are classified into three types: bioinert ceramics, bioactive bioceramics, and biodegradable ceramics. There are different methods for the fabrication of bioceramics, they can be prepared by conventional powder processing methods or by some new unconventional methods. Bioceramics can be fabricated by a sintering process, which takes place through the hardening of the green bodies at a relatively high temperature lower than their melting point. Nowadays, microwave sintering is excellent in both heating efficiency, saving energy and time, and the concomitant processing cost. There are other methods used to obtain bioceramics; such as sol-gel, gas-foaming, gel-casting, and freeze-casting techniques. Recently, the CAD/CAM technique (computer-aided design/manufacture) was used in the fabrication of bioceramics and is applied in the dentistry field. The application of bioceramics connects to the repair of the skeletal system, which consists of joints, bones, and teeth, as well as both soft and hard tissues. Bioceramics can be used to replace parts of the cardiovascular system, especially heart valves.

Microstructural characterization and equibiaxial flexural strength of CeO2 and Ti-doped CeO2

In this study, the synthesis of CeO2 and titanium dioxide (TiO2) doped CeO2 (TDC) monoliths are investigated, and their fracture strength is assessed using an equibiaxial flexure testing technique at room temperature. Pellets were synthesized using conventional powder processing and sintering methods to produce the desired characteristics. The TiO2 dopant concentration was optimized at 0.1 wt % TiO2 to obtain dense, solid-solution pellets with an enhanced grain microstructure. A ball-on-ring fixture was used to obtain the TRS and Weibull parameters of over 30 pellets for CeO2 and 0.1 wt % TDC to compare fracture behavior. The TRS of CeO2 pellets ranged from 88 to 160 MPa and the TRS of 0.1 wt % TDC pellets ranged from 102 to 171 MPa, both being consistent with published values. Weibull parameters, such as characteristic strength and Weibull modulus, were extracted as 129 MPa and 8.5 for CeO2 and 150 MPa and 9.3 for 0.1 wt % TDC, respectively. Although Hertzian contact damage was observed on compressive surfaces, failure initiation occurred on the tensile surfaces of both types of samples. Fracture surface analysis for CeO2 indicated a predominantly intergranular fracture while 0.1 wt % TDC had a predominantly transgranular fracture mode. The TRS of 0.1 wt % TDC resulted in increased Weibull parameters when compared to CeO2, indicating sample chemistry and microstructure impact mechanical behavior for these samples.

Precipitated Calcium Carbonate Derived from Green Mussel Shells Extracted from Magnesium Chloride Containing Solution

Green mussel shells are one of the calcium carbonate-rich biogenic sources. They contain 95.7 to 98.2 wt. % calcium. The high calcium content of green mussel shells was extracted and converted into calcium oxide material in the study by calcination at 900°C for 5 h. Later, at stirring times of 30, 60, 90, and 120 minutes, a solution medium containing magnesium chloride was used to dissolve the resulting calcination powder and subsequent carbonation for producing PCC (precipitated calcium carbonate). According to XRD, Rietveld, and FTIR analyses, the resulting PCC product with calcite-containing Mg was obtained primarily for a short stirring time of 30 minutes during the carbonation process, whereas calcite and aragonite were generated at longer stirring times (from 60 to 90 minutes). Instead, brucite was obtained after 120 minutes of stirring. The PCC product has a non-uniform polyhedrallic morphology of various small and large sizes as observed by SEM. This powder processing method allowed for faster PCC synthesis at a lower cost while requiring no chemical addition to increase basicity.

Practical insights into the recycling of green mussel shells (Perna Viridis) for the production of precipitated calcium carbonate

The study presented a powder processing method involving calcination and subsequent carbonation in the synthesis of precipitated calcium carbonate (PCC) for recycling green mussel shells, which contain a high calcium carbonate content. The purity of portlandite [Ca(OH)2] as a result of calcination and subsequent moisture absorption during storage was verified using the XRD-Rietveld method. Further quantitative XRD Rietveld analysis of the PCC product confirmed the presence of vaterite (55.20 wt.%) and calcite (44.80 wt.%) minerals after carbonation process of the calcined powder product. The SEM examination of this product revealed particle aggregates of non-uniform polyhedral and cubical grains of varying small and large sizes. The FTIR analysis also confirmed that calcination and subsequent hydration of mussel shell powder yielded pure portlandite, whereas the carbonation yielded PCC polymorphism. As a result, this powder processing method is simple to scale and reduces the cost of PCC synthesis, which is critical for practical applications. The current study demonstrated that the powder processing method for recycling green mussel shells as starting materials in biomedical applications is technically feasible.

Wear behavior of high volume Al2O3-reinforced Al7075 matrix composites fabricated by semi-solid powder processing

The aim of the present study is to fabricate high volume Al2O3-reinforced Al7075 matrix composite by semi-solid powder processing method as an effective method to achieve the desired wear properties. The alloy powder (20 µm) was mixed with Al2O3 (120 µm) for 10 min and 5 h by planetary ball mill to overcome the powders agglomeration. The wear behavior of the composites was studied using the pin-on-disk tribometer. The effects of milling time, compact pressure, and reinforcement content were investigated to enhance the wear resistance. The results of the tribotests indicated that composites with coarser reinforcing particles (lower milling time) have good wear resistance. The role of compaction pressure in highly loaded composites is remarkable. The maximum wear resistance was observed for the 50% Al2O3 composite. The wear resistance increased as the reinforcement volume increased before reaching a critical value. Abrasive wear is the predominant mechanism in the wear of reinforced composites containing less than the load limit. However, adhesive and laminating wear are the controlling mechanisms at overloads. The results indicate valuable information in the development of aluminum-based composites.

Mechanochemically synthesized Al–Fe (oxide) composite with superior reductive performance: Solid-state kinetic processes during ball milling

Recently, mechanical ball milling (BM), a simple and green powder processing method, has been successfully applied to improve the performance of zero-valent metals (ZVMs) for efficient water treatment. However, until now BM is still regarded as a “black box” in which the processes of the solid-state reaction during activation remain unclear. In this paper, firstly, FeSO4·7H2O crystal was used to activate and modify inert microscale zero-valent aluminum (mZVAl) by BM to synthesize Al–Fe (oxide)bm composite that showed superior reactivity in reductive removal of various contaminants and excellent reusability, which may be mainly ascribed to the newly formed iron oxide layer on mZVAl by mechanochemical reaction. At the same time, the formation of iron oxides on mZVAl was closely related to BM parameters. Further kinematic analysis revealed that the occurrence of mechanochemical reaction depended on the impact energy and input energy, which BM speed and BM time were two main factors determining reaction extent on the premise that the precursors were full dose. Moreover, kinetic fitting uncovered the solid-state reaction mechanism between mZVAl and FeSO4·7H2O conformed to three-dimensional diffusion and phase boundary reaction models. This study ponders deeply upon the mechanochemical process and solid reaction mechanism during the preparation of Al–Fe (oxide)bm composite, which deepens comprehensions of material synthesis procedures by BM and promotes applications of ZVM-based composite in polluted water or wastewater treatment.

Effect of powder processing and alloying additions (Al/ZrB2) on the microstructure, mechanical and electrical properties of Cu

The present work elucidates the effect of powder processing conditions (milling/mixing) and conductive alloying element (Al: aluminium) and ceramic (ZrB2: zirconium diboride) reinforcement addition on the densification, microstructure and electrical conductivity of copper (Cu) processed via hot pressing route. Disregard of alloying element/reinforcement/content or powders preparation method, the density of Cu materials varied between 92.16 and 99.76% ρth (theoretical density) after hot pressing at a low temperature of 500 °C. In case of Cu-Al alloys, the powder processing method significantly influenced its microstructure and conductivity. Particularly the Cu-Al alloys processed using mixed powders consisted of various phases Cu, α-Cu, γ1 (Cu9Al4), δ (Cu3Al2), ζ1 (Cu4Al3), η2 (CuAl) and θ (CuAl2) and the Cu alloys prepared using milled powders composed of either only α-Cu or α-Cu and γ1 (Cu9Al4) phases (depending on the Al content). Whereas, only Cu and ZrB2 phases were observed with the Cu-ZrB2 composites processed using either milled or mixed powers. In case of Cu-Al alloys, the hardness (0.88–3.41 GPa) and strength (540.30–1120.18 MPa) of Cu increased with the addition of Al. Interestingly, the hardness (0.88–2.55 GPa) and strength (508.50–970.60 MPa) of Cu increased upto 5 wt% ZrB2 and then they lowered with further addition of ZrB2. In particular, the hardness and strength of Cu-ZrB2 composites are lower than Cu-Al alloys reflecting the effectiveness of solid solution strengthening in the Cu alloys as compared to dispersion strengthening mechanism in Cu composite. The pure Cu prepared using milled powders exhibited low conductivity (75.70% IACS) than Cu processed using as-received/un-milled powders (97.00% IACS). Also, the Cu-ZrB2 composites measured with better electrical conductivity than Cu-Al alloys. Depending on the milling conditions and alloying/reinforcement amount, the conductivity of Cu-ZrB2 composites varied between 44.10 and 88.70% IACS.

Sea snail shells for synthesis of ceramic compounds reinforced with metallic oxide: Microstructural, mechanical and electrical behavior

The focus of this study is to investigate the effect of Cu2O formation in the CaO·Al2O3 ceramic compounds synthesized by a powder processing method. For the synthesis, chemical compositions were prepared between CaCO3 powder from sea snail shells, Al2O3 powder, and separate additions of Cu powder at 0.0%, 0.5%, 1.0%, 1.5%, and 3.0% by weight. The chemical compositions were subjected to a mix-milling process, then compacted in cylindrical samples and sintered at 1500ºC for their consolidation in a nitrogen-air atmosphere. The synthesized materials were analyzed by X-ray diffraction and scanning electron microscopy. In addition, the mechanical and electrical properties were evaluated. In the results, the X-ray analysis identified the formation of the CaAl2O4, Ca12Al14O33, and Cu2O phases. The presence of Cu2O in materials causes changes in hardness, fracture toughness, capacitance, and dielectric constant. For example, the material compounds with Cu2O reach a hardness of up to 12.8 GPa, while material without Cu2O reaches a hardness of 7.8 GPa. Likewise, the capacitance is between 11.1 pF and 10.1 pF, respectively. The materials obtained possibly can be used in dental applications, materials with antimicrobial activity, or applied in telecommunication as radiofrequency oscillators, due to their electrical properties.

Mechanosynthesis and Thermoelectric Properties of Fe, Zn, and Cd-Doped P-Type Tetrahedrite: Cu12-xMxSb4S13.

This contribution deals with the mechanochemical synthesis, characterization, and thermoelectric properties of tetrahedrite-based materials, Cu12-xMxSb4S13 (M = Fe2+, Zn2+, Cd2+; x = 0, 1.5, 2). High-energy mechanical milling allows obtaining pristine and substituted tetrahedrites, after short milling under ambient conditions, of stoichiometric mixtures of the corresponding commercially available binary sulfides, i.e., Cu2S, CuS, Sb2S3, and MS (M = Fe2+, Zn2+, Cd2+). All the target materials but those containing Cd were obtained as single-phase products; some admixture of a hydrated cadmium sulfate was also identified by XRD as a by-product when synthesizing Cu10Cd2Sb4S13. The as-obtained products were thermally stable when firing in argon up to a temperature of 350–400 °C. Overall, the substitution of Cu(II) by Fe(II), Zn(II), or Cd(II) reduces tetrahedrites’ thermal and electrical conductivities but increases the Seebeck coefficient. Unfortunately, the values of the thermoelectric figure of merit obtained in this study are in general lower than those found in the literature for similar samples obtained by other powder processing methods; slight compositional changes, undetected secondary phases, and/or deficient sintering might account for some of these discrepancies.

Thermoelectric Properties of Cobalt-Doped β-FeSi2 with SiC Nanoparticle Inclusions

Cobalt doping is an effective approach to improve the thermoelectric properties of semiconducting β-FeSi2 materials. Through preparing β-Fe1−xCoxSi2 samples with x ranging from 0.05 to 0.11, an enhanced ZT of about 0.35 could be achieved within quite a wide doping range (8 mol.% to 10 mol.%) at around 950 K. To further improve the thermoelectric performance, a composite structure consisting of a large grain matrix of β-Fe0.92Co0.08Si2 and inert SiC nanoparticle inclusions was intentionally employed to reduce the lattice thermal conductivity. The microstructure and the effects on the thermoelectric properties of β-Fe0.92Co0.08Si2 with various SiC nanoparticle concentrations were explored. The SiC nanoparticles could be well dispersed into the matrix material without significant agglomerations by the powder processing method. However, the thermal conductivity was not considerably reduced while the electrical properties were affected to some extent, resulting in no gain in the ZT. The current results show that it is feasible to prepare high-quality nanocomposites through the powder processing method, and enhanced thermoelectric performance is expected when using other chemically stable inclusions with lower thermal conductivity and smaller size.

Recent developments on epoxy-based syntactic foams for deep sea exploration

Epoxy syntactic foam (ESF) materials are widely used in marine detection systems, deep sea diving equipment, offshore oil exploration and other deep sea development and exploration equipment due to their superior properties such as low density, high compressive strength and low water absorption. The composition and preparation process of the ESF material determine the structure of the ESF material, the structure determines the performance, and the performance determines the application of the ESF material. The review describes the epoxy-based syntactic foams from the following aspects: definition and classification, preparation methods, properties and influencing factors, application, problems and development trend. The forming methods of hollow glass microspheres (solid-state powder processing method and liquid atomization method), hollow polymer microspheres (spray drying method) and centimeter-sized hollow spheres (rolling ball method and electrostatic fiber flocking method) are introduced in detail, as well as the casting molding method, vacuum molding method and pressure molding method of the syntactic foams. The main objective of this paper is focusing on the influence of various factors including filler content, graded structure, clay material, carbon material, fiber-reinforced material, molding process, material structure (sandwich structure) on the compressive strength and the density of the syntactic foam in detail. The paper may also provide some guidance to the preparation of ESF used in deep sea development and exploration equipment.

Effect of sintering temperatures and foaming agent content to the physical and structural properties of wollastonite based foam glass-ceramics

This study aims to fabricate low-cost foam glass-ceramic using soda-lime-silica (SLS) glass waste and clamshells (CS) as foaming agent in content between 1 and 12 wt.% by conventional powder processing method. The samples were undergoing sintering process between 700 and 1000?C with holding time of 30 minutes and characterized according to the physical and structural properties. Samples containing 3 wt.% CS treated at 800?C show the greatest size of porosity. As the sintering temperature increased, the samples tend to become less dense. However, for the samples sintered at 900 and 1000?C, the trend of the density changes because of the excess CO2 gases generated during the heat treatment process promotes an increase in internal pressure, which results in the rupture of the pore walls. For linear expansion, for samples with a sintering temperature of 800?C and higher, the increment of the temperature will lead to the decrement of linear expansion (%). As the sintering temperature increases from 700 to 800?C, the water absorption (%) increases. However, the percentage of water absorption decreases with the further increment of sintering temperature. The XRD characterization showed the formation of wollastonite phase (CaSiO3) and further revealed the formation of greater peaks of CaSiO3 at the higher sintering temperatures. The results of compressive mechanical strength between 0.15 and 1.50 MPa indicate that the obtained glass-ceramic foams have potential for building material applications.

Selective laser melting of metal matrix composites: Feedstock powder preparation by electroless plating

The objective of this work is to investigate the feasibility to use electroless plating as a feedstock powder production method for additive manufacturing of metal matrix composites (MMCs). MMCs are of importance because of their improved properties compared with existing metallic alloys for additive manufacturing. However, the current powder processing methods (e.g., high-energy ball milling) are difficult to incorporate a high fraction of nanoparticles with a homogeneous dispersion. Electroless plating is proposed to produce MMC powder in this work. Ni/Al2O3 composite powder with a high fraction of Al2O3 nanoparticles was successfully produced using a Ni electroless plating bath containing Al2O3 nanopowder. X-ray diffraction analysis was performed on the prepared powders, showing both Ni and Al2O3 phases as designed. Scanning electron microscopy (SEM) characterization showed the Ni and Al2O3 phases were uniformly distributed in the powder. The Ni/Al2O3 powder was then laser melted into tracks to investigate the effects of process parameters using a commercial selective laser melting (SLM) system. SEM showed stable tracks were achieved under a wide range of process parameters. Both Ni and Al2O3 phases were identified in the melted tracks, possessing a hierarchical micro/nano-structure. The SLM behavior demonstrated the feasibility of electroless plating for producing MMC feedstock powder.

Spark plasma sintering of nickel and nickel based alloys: A Review

Abstract The use of spark plasma sintering technique has been identified as a means of enhancing materials properties, especially nickel-based alloys. Nickel and nickel-based alloys are essential materials that combine different properties which include; high-temperature strength, good mechanical properties, appreciable toughness, resistance to thermal shock, resistance to thermal fatigue, resistance to chemical attack, resistance to creep, resistance to corrosion/oxidation and good surface stability at the high-temperature environment. The above qualities have made alloys gain more patronage and acceptance in recent time. However, a higher percentage of the demand comes from the aerospace industry, gas/steam power plant, petrochemical plant, nuclear reactors and marine industry. Spark plasma sintering is one of the powder processing methods in metallurgy that has been used to fabricate nickel-based alloys with exceptional qualities. The process involves, mixing metallic powders to form the desired stoichiometry composition (in the case of forming an alloy), either by direct mixing or mechanical alloying. The already mixed powder is transfer to a graphite mould and then compacted in the heating chamber of the furnace. Heat is supply to sinter the compacted powder at a temperature below the alloy melting point, in order to ensure metallurgical bonding between the powder particles. The application of spark plasma sintering technology is a promising one, especially for processing nickel alloys. It promotes the formation of gamma (γ) matrix phase, gamma prime (γ’) intermetallic phases, secondary gamma prime (γ”) intermetallic phase and precipitation of solid solution strengthening elements. These are the phases that improve the mechanical properties of sintered alloys. Spark plasma sintering minimizes the problems associated with conventional fabricating routes such as; micro segregation, pores and pin holes.

Response of Al-Based Micro- and Nanocomposites to Rapid Fluctuations in Thermal Environments

The focus of this work is to highlight the relative response of Al-based micro- and nanocomposites in the form of enhancement in flexural strength via induced thermal stresses at high and cryogenic temperatures in ex situ and in situ atmospheres. In this investigation, we have tried to explore the reliability, matrix-reinforcement interaction and microstructural integrity of these materials in their service period by designing appropriate heat treatment regimes. Al-Al2O3 micro- and nanocomposites had been fabricated by powder processing method. The micro- and nanocomposites were subjected to down-thermal shock (from positive to negative temperature) and up-thermal shock (from negative to positive temperature) with varying thermal gradients. For isothermal conditioning, the composites were exposed to + 80 and − 80 °C for 1 h separately. High-temperature three-point flexural tests were performed at 100 and 250 °C on the composites. All the composites subjected to thermal shock and isothermal conditioning was tested in three-point flexural mode post-treatments. Al-1 vol.% Al2O3 nanocomposite’s flexural strength improved to 118 MPa post-thermal shock treatment of gradient of 160 °C. The Al-5 and 10 vol.% Al2O3 microcomposites possessed flexural strength of 200 and 99.8 MPa after thermal shock treatment of gradient of 160 and 80 °C, respectively. The observed improvement in flexural strength of micro- and nanocomposites post-thermal excursions were compared and have been discussed with the support of fractography. The microcomposites showed a higher positive scale of response to the thermal excursions as compared to that of the nanocomposites.

Multifunctional Device based on phosphor-piezoelectric PZT: lighting, speaking, and mechanical energy harvesting

We demonstrated the tri-functional device based on all powder-processing methods by using ZnS powder as phosphor layer and piezoelectric material as dielectric layer. The fabricated device generated the electroluminescent (EL) light from phosphor and the sound from piezoelectric sheet under a supply of external electric power, and additionally harvested the reverse-piezoelectric energy to be converted into EL light. Under sinusoidal applied voltage, EL luminances were exponentially increased with a maximum luminous efficiency of 1.3 lm/W at 40 V and 1,000 Hz, and sound pressure levels (SPLs) were linearly increased. The EL luminances were linearly dependent on applied frequency while the SPLs showed the parabolic increase behavior below 1,000 Hz and then the flat response. The temperature dependence on EL luminances and SPLs was demonstrated; the former was drastically increased and the latter was slightly decreased with the increase of temperature. Finally, as an energy harvesting application, the piezoelectric-induced electroluminescence effect was demonstrated by applying only mechanical pressure to the device without any external electric power.

Note: Progress on the use of MgB2 superconducting joint technique for the development of MgB2 magnets for magnetic resonance imaging (MRI).

This note presents a superconducting joint technique for the development of MgB2 magnetic resonance imaging (MRI) magnets. The MgB2 superconducting joint was fabricated by a powder processing method using Mg and B powders to establish a wire-bulk-wire connection. The joint resistance measured using a field-decay method was <10-14 Ω, demonstrating that the proposed joint technique could be employed for developing "next-generation" MgB2 MRI magnets operating in the persistent current mode.

Enhanced ionic conductivity of scandia-ceria-stabilized-zirconia (10Sc1CeSZ) electrolyte synthesized by the microwave-assisted glycine nitrate process

Scandia-stabilized-zirconia is a potential zirconia-based electrolyte for intermediate temperature solid oxide fuel cells (IT-SOFCs). In this study, the properties of zirconia co-doped with 10mol% Sc and 1mol% Ce (scandia-ceria-stabilized-zirconia, 10Sc1CeSZ) electrolyte synthesized by the microwave-assisted glycine nitrate process (MW-GNP) were determined. The effects of microwave heating on the sintering temperature, microstructure, densification and ionic conductivity of the 10Sc1CeSZ electrolyte were evaluated. The phase identification, microstructure and specific surface area of the prepared powder were investigated using X-ray diffraction, transmission electron microscopy and the Brunauer-Emmett-Teller technique, respectively. Using microwave heating, a single cubic-phase powder was produced with nanosized crystallites (19.2nm) and a high specific surface area (16m2/g). It was found that the relative density, porosity and total ionic conductivity of the 10Sc1CeSZ electrolyte are remarkably influenced by the powder processing method and the sintering temperature. The pellet sintered at 1400°C exhibited a maximum ionic conductivity of 0.184S/cm at 800°C. This is the highest conductivity value of a scandia-stabilized-zirconia based electrolyte reported in the literature for this electrolyte type. The corresponding value of the activation energy of electrical conductivity was found to be 0.94eV in the temperature range of 500–800°C. Overall, the use of microwave heating has successfully improved the properties of the 10Sc1CeSZ electrolyte for application in an IT-SOFC.

Heat press molding of open-celled porous Si-SiC ceramics consisting of skeletal strut via gelcasting with flexible and thermosetting polyurethane resin

A novel powder processing method for the fabrication of thin open-celled porous siliconized silicon carbide (Si-SiC) ceramic substrates is reported. Green SiC–carbon (C) substrate is first formed via a newly developed gelcasting method, using an organic-solvent-based slurry comprised of submicron SiC and nanometer C powders, along with a flexible and thermosetting polyurethane resin, based on the replica method with polyurethane foam as a template. Subsequently, the flexible semi-wet green substrate is uniaxially compressed under heating for molding to a set thickness; this is possible because of its thermosetting property (heat press molding). Although the slurry viscosity is highly sensitive to fine fluctuations in the powder volume concentration (PVC; 0.45–0.48), the PVC criterion for homogeneous powder solidification and improvement in the green SiC–C strut quality is determined to be 0.46. At 0.48 PVC, it is confirmed that the formed green SiC–C struts reproduce the template morphologically with a high correlation coefficient of 0.96 for the average strut thickness. As regards the open-celled sintered Si-SiC substrate (thickness: 6mm), the Si-SiC strut appears to be skeletal with a triangular vertical cross-section, which can be successfully warped or twisted without cracking; furthermore, the mechanical strength is evidently improved via the heat press molding.