Advanced Materials Research Vols. 887-888

Abstract: In this research, a novel composite material is prepared by using light irradiation and thermal curing polymerization under a green production process. The methodology is to alter the composition of the materials, including amounts of hardener, monofunctional monomer, polyfunctional acrylic monomer and epoxy resin. The process is also accompanied with/without fiberglass. The new sample is processed by photo polymerization and heating hardening molding. The property of the novel material was investigated whether was influenced by doping fiberglass and hardener. The mechanical properties of the novel material were examined by using Izod impact test. Its morphology was observed by an optical microscopy. Experimental results showed that the fiberglass doping can increase the strength of resin but does not affect the light hardening reaction and the optical penetration. The research results concluded that a novel epoxy composite material can be synthesized under green production process and improve its toughness by means of photo polymerization and thermal curing dual polymerization.

Abstract: This study is to explore the mixture of the different amounts of nanopowders with different photopolymerizable monomer, polyfunctional monomer and acrylic epoxy resin to prepare novelty nanocomposite materials in green production process. The preparation of nanopowder enforced photopolymerizable resin substrate adopted green production process without solvent that its chemical properties, such asreaction rate, the effect of irradiation dose and operation time, can be controlled in the green production process to solve the underlying issues in applications. The thermal decomposition temperature, thermal expansion, the temperature of glass transition point and transmittance of the material can be measured by various testing methods. The results showed that the thermal decomposition temperature Td had a maximum increase of 17.18 °C. While the powder dosage was 3wt.%. The α₁ has a minimum value, which is 29.21% decrease than the original one, from TMA. These were concluded that a material with an appropriate amount of nanopowder can enhance the performanceof the photopolymerizable substrates to the preparation of novelty materials in green production process.

Abstract: For the further research of 3D tubular woven carbon fiber composite, a unit cell division method and a mechanical model were put forward to predict the engineering elastic constants. The model adopted raceway shape as the yarns cross-section, and prediction methods of volume fractions and elastic modulus were established based on the micro structure and geometric parameters of the yarn. Then the finite element method was used to analysis the mechanical behavior under the circumstances of axial-tensile load, and the stress state was revealed. The results shows that the predicted values using finite element method agree well with the theoretical calculation values, thus the model and analysis method of elastic constants is verified.

Abstract: The properties of CeO₂ -LaB₆/B₄C composite material prepared by hot pressed sintering method was tested, CeO₂ as a sintering aid for boron carbide is investigated in this paper. The study shows: the hardness of CeO₂ -LaB₆/B₄C composite increases with the content of CeO₂. The density, hardness, flexibility strength and the fracture toughness of LaB₆/B₄C composites is greatly improved compared by CeO₂ additive. When the content of the CeO₂ is 1wt%, LaB₆/B₄C composite has its the best mechanical properties. The density reaches its supreme value of 2.676 g/cm³, the hardness reaches its supreme value of 39.19 GPa, the flexibility strength reaches its supreme value of 354.15 MPa and the fracture toughness reaches its supreme value of 5.15 MPa.m^1/2. In conclusion, the density, hardness and flexibility strength of LaB₆/B₄C composite is improved by CeO₂ additive. However,it gives little effect on fracture toughness of LaB₆/B₄C composite. The main fracture way of CeO₂-LaB₆/B₄C composite material is intercrystalline rupture, while the transcrystalline rupture is minor.

Abstract: The development of materials with high damping and energy absorption properties in the form of bulk materials or coatings is today a target for designing components and structures with improved durability and survivability to serve in fields such as aeronautical, mechanical, civil and environmental engineering. This paper presents the results of the dynamic mechanical characterization conducted on reinforced polyurea composites. The mechanical properties of two types of composite materials utilizing the polyurea elastomer as a matrix are compared with those of the pure polymer. The composite materials show a substantial increase of the damping ability. Such materials can be produced in the form of coatings and successfully applied for maximizing the damping of mechanical and structural vibrations or for limiting the damage effects of impact events on structures and components.

Abstract: Lanthanum-copper Composite Oxide Compounds were prepared from lanthanum chloride (LaCl₃) and copper chloride (CuCl₂), and used sodium hydroxide (NaOH) as precipitating agent. The research results showed that: the best preparation condition, which is the copper content3%;water bath temperature,70°C; agitation time,2 hours; calcination temperature,400°C; calcination time,1hour.The adsorption capacity of adsorbent was 63.88mg/g in this state. Analysis results indicate that Copper-doped crystal form dense granule in favour of phosphate adsorption .And La₂O₃ is very important on removing the phosphate.

Abstract: This paper prepared Cu-ZrO₂ composite by a modified internal oxidation in order to improve the high temperature strength of resistance Spot-welding electrode. The results showed that with the increasing of the cold deformation, Hardness increased while electrical conductivity decreases. Hardness reached 100HV and electrical conductivity was up to 86%IACS after cold drawn in 56%. With the increasing of annealing temperature and annealing time, Hardness of the composite decreased more slowly compared with the conventional Cu-Cr-Zr alloy and was higher than that of the Cu-Cr-Zr alloy after annealed above 700°C for 2h and at 600°C for 5h , which was attributed to the dispersion strengthening effect of the Zirconia particles. Thus, the Cu-ZrO₂ composite has good high-temperature stability and can be used for the electrode

Abstract: Steel-polyurethane tube can be widely used in civil engineering. In this paper, 6 axial compression specimens test was carried out on steel-polyurethane tube, the results showed that the deformation of steel - polyurethane composite tube (SPCT) appears the bow drum, the bonding performance between polyurethane and steel is so good that the peeling did not occur. From the load displacement curve and test process, it can be gotten that specimen curve was generally composed of elastic, elastic-plastic, descent and strengthening phases, and it indicated that SPCT has sound ductility and strength reserve to resist dynamic loads.

Abstract: The present paper has discussed the growth inhibition role of silicon additions in Copper / Aluminum composite interface compounds. With different Si content of the aluminum composite sample after the comparison group, and interface with metallographic microscopy and by scanning electron microscopy analysis carried out and found that the Si incorporation can significantly inhibit the Copper / Aluminum interface compounds generated.