Advanced Materials Research Vols. 631-632

Abstract: Transient liquid-phase(TLP) bonding of SiC particle reinforced aluminum matrix composite(SiCp/Al MMCs) ,using Cu film, Cu foil, Ni foil and Cu/Ni/Cu multilayer foil interlayer, was investigated. The effect of surface status, interlayer species and bolding time on bonding microstructure and properties were also estimated by metallographic microscope, scanning electron microscopy (SEM), X ray diffraction and tensile testing machine. The results show that adding holding time can improve shear strength of joint. Better strength of joint can be obtained due to without the effect of oxide with Cu film as interlayer, when bonding at 853K for 120min under 2MPa pressure, the shear strength of bonded joints can obtain 169.1MPa, about 81.7 percentage of the strength of base material. Best strength of joint can be obtained with Cu/Ni/Cu multilayer foil as interlayer, when bonding at 923K for 120min under 2MPa pressure, the of bonded joints can obtain 189.6MPa, about 84.6 percentage of the strength of base material.

Abstract: Load sharing metal lined composite pressure vessel(COPV) enables significant safety and reliability over those vessels with non-load-sharing metallic or non-metallic liners, The key technical challenge in developing these vessels will be to calculate the optimized liner thickness and liner elastic strain. This paper presents techniques developed at Lanzhou Institute of Physics(LIP) for the design of elastically operating metal liner COPV in terms of NET theory which modified by LIP. Five metal materials are discussed and analytical techniques for determining liner thickness are presented, selection of materials for maximizing performance and minimizing weight is discussed. L490A-COPV development is introduced, performance factor is improved from 23 Km to 29.5Km.

Abstract: It was compared AH36 opened plate using new techology with original plates using conventional method in the mechanical properties. Results showed: the mechanical properties of AH36 opened plate and plates of original plate are the same at the classification plate. The transverse tensile stength and yield strength of AH36 opened plate have an advantage over it’s longitudinal. The transverse elongation of AH36 opened plate and original plates are below the longitudinal. It is different the mechanical properties that is made of the deformation variance of AH36 opened plate and original plates in the transverse and the longitudinal.

Abstract: Solidification behavior of LaFe_13-xSi_x alloys was investigated using rapidly quenching and. Phase formation and structure in rapidly quenched LaFe_13-xSi_x alloys has been investigated by means of power X-ray diffraction analysis (XRD) and scanning electron microscopy (SEM). The results have shown that 1:13 phase is a peritectic phase. The solidification behavior of LaFe13-xSix alloys depend on x, cooling rate. Under small undercooling, the 1:13 phase is difficult to formed with x=0.5 to 3.0. The α-(Fe,Si) phase and the 1:2:2 phase is mainly phase in the microstructure of alloy with low and high Si contents, respectively. Under higher cooling rate, the microstructure of compositions with x≥1.5 occurs the 1:13 phase. The α-(Fe,Si) phase and the 1:13 phase is mainly phase in the microstructure of alloy with low and high Si contents, respectively. The microstructure of compositions with x=2.5 to 3.0 are mainly phase which is primary phase. The results were discussed with respect to the effect of cooling rate.

Abstract: This paper describes a composite pressure vessel(COPV) development program which have been finished by Lanzhou Institute of Physics (LIP). In order to dramatically improve reliability and safety of COPV applied in military aircraft, this COPV(L376-COPV) design relies partly on the heritage of mature technologies and was developed in combination with existing and new technologies, Unlike traditional COPV, the impact resistant capability from high energy bullet of L376-COPV is improved greatly by liner material heart treatment and T800/K49 fiber hybrids over-wrap. L376-COPV design, analysis, manufacturing, testing and results was introduced.

Abstract: Particle size distribution (PSD) of a nanodiamond powder in a high concentration suspension was measured by a new dynamic light scattering (DLS) technique based on the Doppler frequency shifting effect. Influence of dispersing pre-treatment, distribution bases and materials’ properties on DLS results was analyzed, and PSD results were validated by TEM analysis. It was found that the optimized ultrasonic dispersing time of the diamond powder in a sodium hexametaphosphate (SHP) solution was about 5 minutes. And median sizes of the nanodiamond powder were 115.6 nm, 53.0 nm and 32.6 nm, based on light intensity, volume and number respectively. PSD results of the nanodiamond based on number accorded well with results from TEM analysis. And PSD results were affected hardly by refractive indices of the diamond and the dispersing medium, while they were affected markedly by viscosity of the medium. It is concluded that this new DLS technique could measure PSD of the nanodiamond powder in high concentration suspensions which has been dispersed properly.

Abstract: We reported on a convenient route to synthesize rhombohedra boron nitride (r-BN) micro-rod using urea (CO(NH₂)₂) and sodium borohydride (NaBH₄) through thermal treatment at 1300 °C. The structure, morphology, and chemical composition of the obtained samples were characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM). In order to determine the phase composition and abundance of the as-synthsized simples, Rietveld refinement has been performed to analyze the XRD data using the Rietan-2000 program. The results show that the abundance of r-BN is about 90.6 wt % and h-BN is 9.4 wt % deduced from Reitveld refinement.

Abstract: In this paper, two kinds of adhesives were introduced into the treatment on polyester fabrics, and all achieved after calendered conjointly with TPU. Then the standing against of water was investigated too.

Abstract: Polymer microcapsules have important application in the fields of biochemistry and materials science owing to their unique structures and functions. Poly(styrene-methyl methacrylate) (PS-co-PMMA) microcapsules were prepared through sonochemical method. The results reveal that it is difficult to form a microcapsule structure from neat styrene (St). However, MMA can improve the interface condition for its higher hydrophilicity. Therefore, it is easier to form hollow structure because polymer microcapsules have a lower interface free energy per unit area. FTIR results confirm that polymer microcapsules have both the typical peaks of PS and PMMA. The results of dynamic light scattering (DLS) and TEM show that PS-co-PMMA microcapsules are uniform in size(about 100 nm in diameter and 20~25 nm in shell thickness).

Abstract: Effect of the energy density on the composition, morphology and deposition rate of the bioglass thin films deposited by pulsed laser was studied by energy dispersive spectroscopy (EDS), scanning electron microscopy (SEM), X-ray diffraction (XRD) and crystal lattice monitor. There is slight compositional difference between the film and the target at lower energy density. Morphology of the films is compact with the particles on the surface of them. Structure of the films is amorphous glass and the size of the particles increases with the energy density. Deposition rate increases with the energy density and the energy density threshold of the film growth is about 2.5J/cm².