Advanced Materials Research Vol. 800

Abstract: According to the movement law of yarn carriers in the four-step braiding technique and the fixed grid method, a script file that calculates the space shape and location data of 3D braided rectangle preform is developed by the software matlab. Via the script file, a space grid diagram of yarns and a APDL file can be got. By calling the APDL file, the entity simulation diagram of 3D braided rectangle preform can be directly produced in the software ANSYS.

Abstract: In this paper, we choose heat resistant material wollastonite and corundum to get the concrete which has heat resistance up to 600 centigrade. SEM reveals that at the temperature of 400 centigrade and 600 centigrade, the material is very dense. But when the temperature gets 800 centigrade and 1000 centigrade, the SEM reveals cracks. The refractory concrete made by magnesium potassium phosphate as the binder and wollastonite and corundum as aggregate has short setting time, early strength and rapid hardening. And it is suitable for emergency repair materials for the kiln.

Abstract: This paper analyse the force of the column base plate which suffering the axial pressure. First, the comparative analysis between the traditional model and interaction model is made. Second, for the steel frame, sole plate and concreat base as a entirety, analyse the factor which affect the stress distribution of sole plate and base top at the different working condition. Result shows that, there is a big gap on the result between the traditional model and interaction model, difference of length-wide ratio of box column section have a small affect on the stress of base top. The change of concreat strength have a big affect on the sole plate and concreat stress distribution.

Abstract: The Ag nanoparticles was prepared by reduction of silver nitrate with sodium citrate, and the APS monolayers was self-assembled with 3-Aminopropyltrimethoxysilane (APS) on the monocrystalline silicon surface. Then, Ag/APS molecular self-assembled film was formed with Ag nanoparticles and APS membrane by liquid method. The chemical structure and morphology of the Ag nanoparticles and self-assembled film were investigated by AFM, XRS and IR. Meanwhile, the friction performances of self-assembled film was also investigated. The results shown that the Ag nanoparticle have the morphology of spherical particles with an average particle size of ca. 65 nm in diameter which were successful assembled on the surface of APS film and partially oxidized into Ag₂O. The friction coefficient of the Ag-APS molecular self-assembled film has been decreased with the assembled time extened while the wear rate has improved.

Abstract: Cast aluminium alloy 354 has extensive applications in the automobile industry. Due to its attractive combination of mechanical properties and excellent castability, it is being used in production of automobile components like the compressor wheel for turbochargers. Performance of this component under fatigue loading conditions is a critical issue. The present study explores the possibility of improving the fatigue life of the component by bringing in process changes (i) adopting a two-step aging treatment in place of the normally used single step aging treatment (ii) adopting a lower artificial aging temperature (171°C) instead of the temperature normally used for artificial aging (188°C) while performing T61 treatment. In all cases Weibull analysis of fatigue test results was carried out. Weibull analysis of Ultimate Tensile Strength (UTS) values obtained after artificial aging at 171°C and 188°C was also carried out. Among the four variants of two-step aging treatment carried out, the one consisting of 100°C for 5 hours followed by 170°C for 5 hours was found to have the best characteristic fatigue life for the components. The modified T61 treatment where aging was carried out at 171°C instead of the normally used 188°C yielded better characteristic fatigue life as well as better Ultimate Tensile Strength (UTS).

Abstract: A series of experiments were carried out to investigate the effect of wollastonite and fly ash combination on the compressive strength, flexural strength, modulus of elasticity, coming off amount, loss percentage of dynamic elastic modulus as well as surface scaling of concrete. The studies show that the effect of mixing wollastonite and fly ash can reach excellent mechanical and durability performance. The effect of mixing wollastonite and fly ash improve the mechanical and durability is better than mixing fly ash alone. The concrete mixes containing wollastonite and fly ash indicated that wollastonite addition 15% was found advantageous in improving concrete quality.

Abstract: In the present study, corrosion and cathodic protection (CP) characteristics of concrete piles exposed to marine environments such as marine bridge columns or pier structures were evaluated under simulated conditions. The accelerated environmental tests were carried out at an elevated temperature (40°C) and a high chloride concentration (15%). The protection potential of CP systems with Zn-mesh sacrificial anodes applied to piles was inversely proportional to the water content in the concrete. When the CP system was applied after corrosion initiation and propagation (CProt), the protection current density was higher than when the CP system was applied at the beginning of structural construction (CPrev). However, the four-hour depolarization potential was higher in the latter case than in the former. In addition, it was found that even though the current density of the CPrev system was relatively lower than that of the CProt system, the CPrev system was also able to prevent corrosion. Consequently, both CProt and CPrev systems are very effective at preserving reinforced concrete structures, especially in marine environments.

Abstract: A new kind of Mg-12Li-3Gd-3Y-0.6Zr alloys was prepared in vacuum conditions with the protection of argon atmosphere. The effects of heat treatment on the microstructure and mechanical properties of Mg-12Li-3Gd-3Y-0.6Zr alloy were studied by optical microscopy, SEM, XRD and tensile test. The results show that the highest tensile strength of the alloy reaches 142MPa after aging treatment at 373K for 2h, and the best elongation of the alloy reaches 54% after solid solution and aging treatment at 673K for 2h + 373K for 2h. The X-ray analysis of the investigated alloy shows that the phase structure of the investigated alloy is β-Li, Mg₂Gd and Mg₂₄Y₅.

Abstract: s: The effects of homogenizing treatment and thermal process on microstructures and mechanical properties of Mg-12Li-0.5Al-1Zn alloy (LAZ1201) were studied. The results show that the grains of LAZ1201 alloy are refined evidently and the dynamic recrystallization happens during thermal process. The tensile strength and elongation of the as-cast LAZ1201 are 138MPa and 38%, respectively. In this paper, the best mechanical properties with a maximum tensile strength of 166 MPa and elongation of 50% were achieved by 30% rolling.

Abstract: Silicone rubber has excellent performance, such as cold resistance, heat resistance, ozone resistance, thermal properties and insulating properties and so on. However, silicone rubber is in the state of semi-liquids and it is very soft, so the mechanical properties of silicone rubber are very poor. In order to improve its availability of silicone rubber, short basalt fiber / silicone rubber composite materials were prepared by using short basalt fiber as reinforcement, and its mechanical properties and compatibility were studied. The best formulation of short basalt fiber / silicone rubber composite materials were determined by testing Shore A hardness, tensile strength and elongation at break, and the morphology structure and compatibility of short basalt fiber / silicone rubber composite materials were discussed by scanning electron microscope and infrared spectrum, prepare excellent performance of silicone rubber composite materials.