Infiltrated Material Research Articles

Fabrication of Cu-Infiltrated Journal Bearing by Binder Jetting Additive Manufacturing

In this study, considering the economic feasibility of products that can be produced through the binder jetting additive manufacturing process, 316L stainless steel, a widely used material with a wide particle size ranging from 15 to 106 μm, was used. The lubrication effect was increased by internal patterning through design for additive manufacturing, and journal bearing parts with excellent load resistance and wear resistance were implemented by using wear-resistant Cu as an infiltration material. In addition, to investigate the amount of Cu infiltrated as a function of porosity, the parts were pre-sintered from 1423 K to 1573 K, and the best performance was obtained when Cu was infiltrated after pre-sintering at 1473 K. As a result of rig testing of Cu-infiltrated journal bearings, mechanical properties were obtained that were more than 50% improved compared to those of mass products.

Developing high-performance oxygen electrodes for intermediate solid oxide cells (SOC) prepared by Ce0.8Gd0.2O2−δ backbone infiltration

Gd0.2Ce0.8O 2−δ (GDC) porous backbone infiltration with La0.6Sr0.4CoO3−δ (LSC), PrOx and LSC: PrOx as a composite oxygen electrode for intermediate solid oxide cells are conducted within the scope of this work. Samples were characterized using scanning electron microscopy (SEM), energy dispersive X-ray spectroscopy (EDX), and electrochemical impedance spectroscopy (EIS). A uniform distribution of the infiltrated material inside the backbone and at the electrolyte-backbone interface was achieved. EIS measurements on the prepared symmetrical samples showed electrode polarization resistance (Rp) values of 0.029 Ω.cm², 0.23 Ω.cm², and 0.44 Ω.cm² for LSC, LSC: PrOx, and PrOx at 600 °C, respectively. Long-term stability measurements at 600 °C for 100 h showed a slight increase in polarization resistance during the measurement period. Fuel cell measurements of commercial cells (Elcogen) with porous oxygen electrode consisting of GDC infiltrated with LSC showed an increase in power density compared to the reference cell with a value of 0.53 W.cm− 2 obtained at 600 °C. It is proven that infiltration via polymeric precursor into porous scaffolds as backbone oxygen electrode layer is effective and convenient method to develop high performance and stable solid oxide cells.

Experimental and clinical substantiation of the combined use of resin infiltrant and flowable composite material in minimally invasive treatment of dental fluorosis.

Обоснование. Для устранения белых пятен при флюорозе зубов на сегодняшний день применяются методики реминерализирующей терапии, микроабразии и инфильтрации, которая имеет особенности проведения при данной патологии вследствие глубокого расположения зоны гипоминерализации. Целью данного исследования является изучение адгезионной прочности текучего композитного пломбировочного материала к инфильтранту ICON и эмали зуба при флюорозе, а также оценка результатов сочетанного применения инфальтрации смолой и композитного материала в клинике. Методы. Изучение адгезионной прочности на отрыв при применении различных материалов проведено на 60 удаленных зубах с флюорозом, а именно с поражениями в виде пятен белого цвета. Методом случайной выборки зубы с флюорозом были разделены на 4 группы по 15 зубов в каждой (1, 2, 3, 4 группы). Для формирования дефекта с целью изучения адгезионной прочности с помощью пескоструйного аппарата (Rondoflex, CAVO, Германия) проводили обработку в центре вестибулярной поверхности порошком на основе оксида алюминия с размером частиц 27 микрон на расстоянии 1 см в течение 3 секунд. Результаты. Наилучшие показатели адгезионной прочности на отрыв получены при применении универсальной адгезивной системы и низкомодульного композитного материала, а также при сочетании применения инфильтранта и низкомодульного композитного материала, содержащего МDP-мономер. Полученные в экспериментальном исследовании результаты позволили рассмотреть сочетание инфильтранта и низкомодульного композитного материала на основе МDP-мономера как перспективный вариант для применения в клинике при минимально-инвазивном лечении флюороза зубов. После проведенного лечения по ранее описанной схеме при осмотре через 1 месяц не выявлено нарушения краевого прилегания, окрашивания границы и вторичного кариеса, отмечен 1 случай чувствительности. При осмотре через 1 год не наблюдалось нарушения краевого прилегания и развития кариеса по границам проведенного лечения и не отмечено случаев развития чувствительности. Заключение. Результаты проведенного экспериментально-клинического исследования свидетельствуют о высокой эффективности минимально-инвазивного лечения флюороза зубов с применением сочетания инфильтрации и низкомодульного композитного материала на основе MDP-мономера.

High-temperature tensile strength of alumina-spinel refractory by Brazilian test at 1200°C coupled with DIC in-situ monitoring

This study investigated for the first time the corrosion effect of Al2O3-MgAl2O4 refractory by steel ladle slag using a DIC-coupled Brazilian test at 1200 °C. Three types of alumina-spinel materials were used in the test, namely, original non-infiltrated refractory, slag-infiltrated at 1450 °C as well as postmortem refractory after 69 cycles of work in the sidewalls of steel ladle. Lab infiltration was conducted at 1450 °C using CaO-Al2O3-SiO2-based ladle slag and its analog enriched with manganese (10% MnO). The tensile strength of postmortem material at 1200 °C was the highest at 10.7 MPa, and it was 52% and 70% higher than for reference and MnO-enriched slag, respectively, and 80% higher than for original refractory. The significantly raised tensile strength of slag-infiltrated materials vs. original non-infiltrated brick was directly related to the densification of microstructure by corrosion products (mainly CA6, CA2, Fe) which caused the infiltrated materials to be stiffer and with a more brittle nature to fracture.

Comparison of color stability and microleakage of bioactive material and a resin infiltration material on hypomineralization in primary teeth

Aim: The current study aimed to evaluate and compare, in vitro the colour stability and microleakage of a bioactive material and a resin infiltration material on hypomineralization in primary teeth. Methods: Sixty human primary molars and incisors, which has been exfoliated or extracted were immersed in a demineralizing solution. 20 each specimen were treated by a bioactive compound (ACTIVA KIDS Bioactive-RESTORATIVE, PULPDENT, USA) (Group A), resin infiltration (Icon, DMG, Germany) (Group B) and as Control group (group C). Evaluation of colour stability and microleakage was done by using spectrophotometer analysis. The difference in color stability and microleakage of all three groups was determined by statistical analysis with a one-way ANOVA test for the proportion of the groups. p<0.05 was considered as statistically significant. Results: The bioactive compound showed statistically significant colour stability and lesser microleakage than resin infiltration material. Conclusions: Since bioactive compound exhibited better colour stability as well as showed lesser microleakage, it can be recommended for the restoration of the hypomineralized primary teeth. Keywords: Bioactive; Dental; Materials; Tooth Hypomineralization

Modifying C/C–SiC brake pads with different Fe–Si alloy phases to improve the wear resistance of full-carbon/ceramic brake pair

The full-carbon/ceramic brake pair is designed to meet the increased demands for reliable braking at high speeds, heavy loads and complex service environments for vehicle and power machinery. In this paper, braking performance of different Fe–Si modified C/C–SiC composites have been studied using laboratory scale dynamometer. The phase composition/microstructure and mechanical properties of the material were studied. By mating with C/C–SiC brake disc, the effect of Fe–Si alloy modification on the friction and wear performance of full carbon/ceramic brake pair was investigated. The results indicated that the Fe–Si modification can effectively improve the wear resistance of both C/C–SiC disc and pads, and the disc/pads will have the least amount of wear only when the appropriate type of Fe–Si alloy and the suitable amount of Fe–Si alloy phase are introduced. When FeSi75 was used as the fusion infiltration material, the wear of disc/pad was 115.4 and 13.3 mm, respectively. Compared to the unmodified C/C–SiC disc/pad, the wear of Fe–Si modification disc/pad was reduced by 72.7 % and 87.2 %, respectively.

INFLUENCE OF CERAMIC MATERIALS AND PREPARATION DESIGNS ON THE MARGINAL ADAPTATION OF INLAYS AND ONLAYS AFTER THERMOCYCLING.

To evaluate inlay and onlay marginal adaptation of two different ceramic materials using two intracoronal preparation designs. An examination of the marginal adaptation of two materials-lithium disilicate (LD; IPS e.max CAD) and polymer infiltrated ceramic network material (PICN; Vita Enamic)-and two preparation designs, where D1 represents MOD inlay preparation with no cusp reduction and for D2, in addition to the basic MOD preparation, the buccal cusps (functional cusps) were reduced by 1.5 mm. Four sub-groups (LD-D1, LD-D2, PICN-D1, PICN-D2) were conducted. In total, 40 (n = 40) mandibular molars were used. A stereomicroscope was used to assess the marginal gap before, after cementation and after thermocycling. Values were calculated for the mean, median, SD, minimum, maximum, and 95% CI. Pairwise comparisons using Tukey post-hoc test were performed following an ANOVA significance of P ≤ .05. The results revealed that lithium disilicate showed statistically significantly higher mean gap distance than PICN material (61 μm to 99 μm). Pairwise comparisons showed that D2 design has statistically significant higher mean gap values than D1. Both LD and PICN material provided marginal adaptation within clinical accepted range. PICN material restorations provided better fit than lithium disilicate restorations. Cusp coverage has a greater marginal gap compared to conventional preparation.

Magnetic properties of nickel electrodeposited on porous GaN substrates with infiltrated and laminated connectivity

We studied the magnetic properties of ferromagnetic-semiconductor composites based on nickel and porous-GaN, motivated by the effort to couple magnetic and semiconductor functionality. Nickel-infiltrated and nickel-coated (laminated thin-film) porous GaN structures were fabricated by electrodeposition, and their magnetic properties were subsequently examined collectively, by vibrating sample magnetometry and on the nanoscale, by magnetic force microscopy. We successfully demonstrated the ability to realize nickel infiltrated porous GaN, where the magnetic properties were dominated by the infiltrated material without a measurable surface contribution. We found that the structure and magnetization of electrodeposited porous-GaN/Ni composites depended on GaN degree of porosity and the amount of deposited nickel. The magnetization evolves from a nearly isotropic response in the infiltrated structures, to a shape-anisotropy controlled magnetic thin-film behavior. Furthermore, both infiltrated and thin-film nickel electrodeposited on porous GaN were found to have low (< 0.1%) strain and corresponding low coercivity: < 6.4 and < 2.4 kA/m for infiltrated and thin-film, correspondingly. An unconventional trend of increased remanence at room temperature, compared to cryogenic temperature, was observed in the thin film. The most likely cause for these findings is increased compliance of the porous GaN compared to bulk, allowing strain relaxation at room temperature. These results encourage deeper investigation of magnetic nanostructure property tuning and of magnetic property coupling to GaN and similar materials.

Long-Term Effect of Nanosized Boric Acid Powder on Optical Properties of Polymer Infiltrated Ceramic CAD-CAM Material

The current study investigated the effect of boric acid (H3BO3) nanosized powder on the optical properties of a Computer-Aided Design and Computer-Aided Manufacturing (CAD-CAM) polymer infiltrated ceramic material. Specimens (n = 60), (15 × 8 × 1.5 mm3) were fabricated from a polymer infiltrated ceramic network (PINC) (Vita Enamic, Vita Zahnfabrik, VITA-shade scale A2). Boric acid (B) nano powder was applied to Vita Enamic in half of the specimens (n = 30), while the other half was left untreated (NB) (n = 30). Aging for all specimens was performed for 5 h at 134 °C. Color coordinates (L*, a*, and b*) before and after aging were measured to calculate the color change (ΔE00) and the translucency parameter (TP) within and between the B and NB groups. One-way ANOVA was used to analyze the effect of boric acid on all color parameters (α = 0.05). Only L* increased in B after aging (p &lt; 0.001). L* and b* significantly changed after aging in NB (p &lt; 0.001). Boric acid application affected the color change within the ceramic after aging (p &lt; 0.001). The mean color change (ΔE00) in B after aging was significantly smaller than the color change in NB after aging (p &lt; 0.001). The color difference between B and NB increased after aging (p &lt; 0.001). No significant effect of aging was found on TP of B (p = 0.143). The TP of NB significantly decreased after aging (p &lt; 0.001). The use of boric acid provided color stability and translucency on aged tested material.

Evaluation of Resin Infiltration, Fluoride and the Biomimetic Mineralization of CPP-ACP in Protecting Enamel after Orthodontic Inter-Proximal Enamel Reduction

This study investigated the effect of using different agents for protecting enamel proximal surfaces against acidic attack after interproximal reduction (IPR) using the trans micro radiography technique. Seventy-five sound-proximal surfaces were obtained from extracted premolars for orthodontic reasons. All teeth were measured miso-distally and mounted before being stripped. The proximal surfaces of all teeth were hand stripped with single-sided diamond strips (OrthoTechnology, West Columbia, SC, USA) followed by polishing via Sof-Lex polishing strips (3M, Maplewood, MN, USA). Three-hundred micrometers of enamel thickness was reduced from each proximal surface. The teeth were randomly divided into 5 groups: group 1 (control un-demineralized) received no treatment, group 2 (control demineralized) had their surfaces demineralized after the IPR procedure, group 3 (fluoride) specimens were treated with fluoride gel (NUPRO, DENTSPLY, Charlotte, NC, USA) after the IPR, group 4 (Icon) resin infiltration material (Icon Proximal Mini Kit, DMG, Bielefeld, Germany) was applied after IPR, group 5 (MI varnish) specimens were treated with Casein phosphopeptide-amorphous calcium phosphate (CPP-ACP) containing varnish (MI Varnish, G.C, USA, St. Alsip, IL, USA) after the IPR. The specimens in (groups 2-5) were stored in a 4.5 pH demineralization solution for 4 days. The trans-micro-radiography (TMR) technique was conducted to evaluate the mineral loss (∆Z) and lesion depth of all specimens after the acid challenge. The obtained results were analyzed statistically using a one-way ANOVA at a significance level of α = 0.05. The MI varnish recorded significant ∆Z and lesion depth values compared to the other groups p > 0.05. There was no significant difference in ∆Z and lesion depth between the control demineralized, Icon, and fluoride groups p < 0.05. The MI varnish increased the enamel resistance to acidic attack, and thus can be considered an agent capable of protecting the proximal enamel surface after IPR.

Transport Characteristics of Tailing Sand Particles under Slotted Tube Overlapped with Geotextile and Steel Mesh

Compared with a one-dimensional test, a two-dimensional test has the potential to study the transport characteristics of particles in tailings under different filtration materials. Due to the different test conditions and the complex test environment, the existing devices generally have limited measuring range or high accuracy. Thus, it is urgent to develop an advanced device to improve the ability of the transport characteristics of particles. In this study, a two-dimensional radial flow device is designed for analyzing the transport characteristics of particles which combine the water tank with adjustable pressure and the seepage body providing a tailing sand environment. An experimental system is built, and a seepage process is carried out to explore the transport characteristics of particles. The results indicate that when head difference remains stable, the mixture consisting of the tailing sand and water gradually transports to the vicinity of the slotted tube along the diameter direction. With an increase in head difference, the tailing sand particle size in the mixture shows a slow upward trend, which migrates in the tailing sand. And the proportion of tailing sand particles with different sizes varies under different head differences. Separation of the mixture consisting of tailing sand particles and water occurs near infiltration material, while the mixture has different transportation laws under different filtration materials. Under geotextile, most fine tailing sand particles which transport from the edge remain in geotextiles, causing an increase in the proportion of fine particles around the slotted tube. However, most fine particles pass through steel mesh, leading to a decrease in the proportion of fine particles.

A facile synthesis approach of silica aero-gel/eicosane particles and its potential application on polyester fabric to impart thermoregulation properties

This article aims to study the thermo-regulating properties of infiltrated Phase change material (PCM) micro-particles treated on polyester fabric. The melt infiltration method was implemented for the synthesis of the Silica aero-gel/Eicosane particles by dispersing eicosane in silica aero-gel. Synthesized particles were incorporated into the polyester knitted fabric by both exhaustion dyeing and coating method to impart the thermoregulation characteristics. The crystalline structure and the particle size of aero-gel infiltrated PCM particles were measured by X-ray diffraction (XRD) analyzer. The presence of eicosane particles deposited on the fabric surface was confirmed by the Fourier Transform Infrared Spectroscopy (FT-IR) and Scanning Electron Microscope (SEM). Finally, while the sample was subjected to heating, both the dyed and coated fabric showed resistance against the rise of temperature due to the presence of phase transition PCM micro-particles compared to the untreated raw fabric sample.

Remineralization potential, hardness and color change of artificially demineralized enamel treated with grape seed extract gel and restored with resin infiltration

Aim This research aimed to evaluate the remineralization potential, hardness and color change of teeth restored with resin infiltration versus comparators that were pretreated with grape seed extract (GSE) gel before resin infiltration. Methods Thirty-six teeth samples were artificially demineralized. The samples were randomly assigned to two groups: group 1: teeth restored with resin infiltration material (Icon) and group 2: teeth pretreated with GSE gel before resin infiltration with Icon. A scanning electron microscope was used to examine teeth samples before and after demineralization and after restoration. Energy dispersive radiograph analysis was employed to analyze the calcium and phosphorus weight percent of samples before and after restoration to detect remineralization. Both groups were subjected to a hardness test using a Vickers microhardness tester. Color change after the restoration of the two groups was detected using a spectrophotometer after 1 day and 1 month of immersion in deionized water. Results Group 2 exhibited occlusion of defect microporosity with a more uniform surface compared to group 1. Group 2 had significantly higher calcium weight %. Both groups showed significant improvement in hardness but a nonsignificant mean difference between the two groups. Color change after 1 day and 1 month were significant for both groups but ΔE values after 1 month are within the clinically acceptable range for a color change compared to intact enamel. Conclusion Pretreatment of artificially demineralized enamel with GSE gel before resin infiltration is a promising procedure that can bridge the gap between the noninvasive and minimally invasive treatment of white spot lesions.

Light harvesting hexamolybdenum cluster integrated with the 3D ordered semiconductor inverse opals for optoelectronic property

Solar energy-harvesting materials have significantly contributed to the development of energy-saving applications for several decades. We have mainly used a new concept composed of the electrophoretic deposition technique and photonic crystal structural engineering to understand the tunable light-absorption and electronic conduction properties. A hexamolybdenum cluster compound (denoted as the Mo6 cluster) was successfully functionalized on a tin pyrophosphate semiconductor integrated within an inverse opal photonic crystal. The size of the periodical pores, surface modification, and chemical composition of the infiltration material of the inverse opal film have been investigated to control the photonic bandgap in the visible range and the efficiency of the deposited Mo6 cluster. The photoactive Mo6 clusters act as a visible light harvester and generate an efficient photo-induced current upon light absorption that is enhanced by a slow photon effect occurring at the photonic stopband edges. The electron and proton are transferred in the inorganic-organic network via hydrogen bonds by a hopping mechanism to generate a rapid photoconductivity response during light irradiation. Specific attention focused on the role of humidity and temperature regarding the reproducibility of the experiments and the photosensitivity of the nanocomposite. The suitable tunable photo-induced conduction property in organic-inorganic materials opens a new opportunity for the applicability of cluster-based compounds in visible optoelectronic devices.

The control efficiency and mechanism of heavy metals by permeable pavement system in runoff based on enhanced infiltration materials

As one of the commonly used stormwater management measures, permeable pavement system (PPS) played a prominent role in controlling runoff pollution and alleviating urban waterlogging. In this study, new enhanced infiltration materials (construction waste brick, coal gangue, activated carbon, multi-walled carbon nanotube, multi-layer graphene) were applied in PPS and the control efficiency and mechanism of typical heavy metals (HMs, Mn2+, Pb2+, Zn2+, Cu2+, Cd2+, Ni2+) was investigated in runoff. Furthermore, the influences of different rainfall intensities and antecedent dry periods on HMs removal by PPS were evaluated. The results showed that all PPS with enhanced infiltration materials have little leaching effect on HMs (＜3 μg/L). All the selected enhanced infiltration materials meet the requirements of PPS. The concentration of HMs in the effluent of PPS dropped sharply first, followed rebounded and then maintained at a stable range. Activated carbon PPS (AC), Multi-walled carbon nanotube PPS (MCN), and Multi-layer graphene PPS (MG) could significantly improve the control effect of PPS on nearly all selected HMs. The average removal rates of AC, MCN and MG for six HMs were 75.48%–99.35%, 81.30%–97.59%, and 73.03%–99.33%, respectively. Compared with Traditional PPS (TR), the effluent concentrations of HMs in construction waste brick PPS (CW) and coal gangue PPS (CG) were relatively higher and unstable. AC, CN and MG could adapt to different rainfall conditions and the maximum removal rates of most HMs exceed to 99%. With antecedent dry periods increased, the control effect of HMs was significantly improved. The influences of the antecedent drying period on HMs removal followed as: CW＞CG＞TR＞MG＞CN＞AC. This study provided novel methods to eliminating HMs in runoff and provides implications for the design of PPS.

An Insight into Enamel Resin Infiltrants with Experimental Compositions.

Resin infiltration is a conservative treatment of initial enamel carious lesions. Only one infiltrant material is available on the market (Icon, DMG), and research is now investigating new chemical compositions so as to further exploit the benefits of the resin infiltration technique. A literature search of the articles testing the effects of different formulations on mechanical properties, resin penetration ability, remineralizing, and antibacterial activities was conducted. Of 238 articles, 29 resulted in being eligible for the literature review. The formulations investigated were all different and consisted in the inclusion of hydrophobic monomers (i.e., BisEMA, UDMA), solvents (ethanol, HEMA), alternative etchants (PAM) or molecules with antibacterial or bioactivity features (i.e., AgNP, YbF3, MTZ, chitosan, DMAMM, HAp, MC-IL, NACP, PUA, CHX) and microfilled resins. Information on the long-term performances of the tested experimental materials were scarce. The combination of TEGDMA with hydrophobic monomers and the inclusion of a solvent alternative to ethanol reinforced mechanical properties of the materials. Hybrid-glass materials demonstrated an enhanced remineralization capacity. Techniques such as tunnelization increased the penetration depth and preserved the recourse to less-conservative treatments. Combining the min-invasive infiltrant approach with remineralizing and bacteriostatic properties would be beneficial for therapeutic and economical aspects, according to the principles of minimally invasive dentistry.

Investigation on Enamel and Dentine of Tooth through 1D Photonic Structure to Identify the Caries in Human Teeth.

In this research, a one-dimensional (1D) photonic structure was employed to study the nature of both enamel and dentine teeth at the signal of 1.8 THz. A simple three layer one-dimensional crystal is chosen to avoid fabrication intricacy. The materials and methods for sample preparations are discussed. The principle of investigation of caries in the teeth relies on the amount of reflected signal from the structure. Similarly, reflectance is a function of refractive indices and thickness of each layer, the nature of both substrate and infiltrated materials, and the configuration of the structure. Apart from this, the fabrication process of one-dimensional structure and experimental set-up was proposed in this article. The numerical treatment is explained here to obtain reflectance, and subsequently, the output potential. Comparison studies on output potential between enamel and dentine are also shown through graphical representation. The output result in terms of milli-Volt (mV) were obtained at the output end and collected at the photodiode. Interesting results were also observed at the photodetector. For example; the output potential of the reflected signal is around 0.18 mV for both enamel and dentine teeth whereas the potential is more than 0.26 mV and 0.31 mV for caries in dentine and enamel, respectively. Finally, it was inferred that the nature of teeth pertaining to the caries in the enamel and dentine teeth can be investigated by identifying the amount of potential at the output end.

3D resistor-network modeling of infiltrated SOFC electrodes

For first time a 3D simulation for infiltrated electrodes taking into account the charge transfer resistance (CT) for computing the admittance is developed. By employing a three-dimensional voxelised resistor network, we study the electrode resistance as a function of electrode microstructure and material conductivities. The simulated electrodes consist of pores, metal and ion conductor material and were generated from a random sphere insertion model which emulates the experimental procedure of the infiltration process. To both evaluate and validate the proposed model, a comparison with numerical models and experimental results from the literature is used. More accurate results closely related to those observed experimentally and the use of the main characteristics of the infiltrated electrodes as input parameters are benefits of 3D modeling. The results show that the model for the admittance and TPBL curves have the same behavior as a function of the amount of infiltrated material. This similarity is fulfilled when the diffusion of gas in the pores of the electrode is not the limiting process for the calculation of the admittance, and when the percolation of the ionic and electronic conducting phases are considered in the calculation for TPBL.

Fabrication of SiC matrix composite material by pressureless aluminum melt infiltration in air atmosphere

The microstructure of SiC matrix composite materials produced by pressureless aluminum melt infiltration at 950° was investigated. The oxygen containing phases fraction in silicon carbide preform does not considerably change after soaking in molten aluminum due to the formation of a dense flux film at the surface. It is established that during the direct infiltration of aluminum from the melt into sintered SiC preform, several areas are observed: aluminum saturated zone, transition zone, and a porous silicon carbide zone. The depth of the first area is 1.0–1.2 mm. The open porosity of the infiltrated composite material significantly improved from 8.5% for a SiC preform to 2.4% as well as density increased from 2.17 to 2.85 g/cm3. Even aluminum content in the zone of porous silicon carbide has grown 5.5 times. The corundum phase has formed at the composite material surface within cooling in the air atmosphere. The hardness distribution over the specimen depth has a parabola-like appearance with a clear maximum on the surface (5.9± 0.6 GPa) and an obvious minimum coinciding in value with the hardness of the initial preform in the geometric center of the sample (2.5± 0.3 GPa). The developed silicon based composite material could be considered as a prospective wear resistant lining.

Study on the characteristics of moist soil under the condition of water supply of surface capillary

In order to explore the characteristics of moist soil under the condition of water supply of surface capillary, this research constructed device which screens the capillary source infiltration based on the tests. Embedding TDR monitoring instrument in the indoor soil box, it can detect the characteristics of moist soil under the conditions of different capillary source infiltration water percolating capacities. The results show that there is a power function relationship between the cumulative infiltration quantity and time under the condition of water supply of surface capillary. The wetting front pushes forward like semi ellipse curve, and the moist soil presents like approximate semi ellipsoid. When the infiltration time and infiltration rate are constant, the soil water content in the infiltration point tends to a stable value, the soil water and heat coupling movement is complex, and the numerical variation tendency of each monitoring point is similar. Based on the above results, we construct empirical solution equation to predict the eigenvalues of soil wetting body under the condition of water supply of surface capillary. In this research, the capillary source infiltration material is found, and the surface capillary source water supply device with low cost and high efficiency is constructed. The device makes the growth of plants with enough water for the first year, but it can still keep the roots dry enough to make the seedling root down. Preventing soil evaporation loss, slowing down water loss of the surface micro environment of the main land and other bad influence, the device can improve the efficiency of water use. Meanwhile, the device can effectively enhance the ability of seedlings against high temperature of the surface in desertification area, wind-blown sand, animal browsing stress, damage, and create a proper environment for the normal growth of plants, which enjoys broad prospects.