Advanced Materials Research Vols. 239-242

Abstract: Two identical zigzag-shapes and an aluminum zigzag shape foil were combined as a slice testing piece. Each of the pieces was connected with AC. 110 V and AC. 12 V. The result indicated that the piece, whose tooth was 10mm wide with intervals of 15 mm, displayed an electromagnetic shielding effectiveness (EMSE) of 30 mG with the load current of AC. 110 V. The EMSE of another piece, whose teeth wide was 5 mm with intervals of 10 mm, was 20 mG in the load current of AC. 12 V. This result proved that samples were with EMSE under the alternating current.

Abstract: Using the injection molding method, impact-resistant polypropylene (PP) and glass fibers (GF) with weight ratios of 5 wt%, 10 wt%, 15 wt%, 20 wt%, 25 wt% and 30 wt% were blended twice, completing high-impact PP/ GF composites. Next, the tensile strength test, flexural stress test and IZOD impact strength test measured the composites. According to the results, with an increase in glass fibers, the composites exhibited a greater tensile strength, which further reached to climax when the GF weight ratio was 25 wt%. However, tensile strength appeared inversely proportionate to the blending frequency. In addition, regardless of blending frequencies, the optimum flexural stress occurred when the GF weight ratio was 25 wt%; nevertheless, it started declining when the ratio was 30 wt%. Finally, indicated by IZOD impact test, the greater the GF weight ratio, the lower the impact strength the composites exited.

Abstract: In 2002, TC8-01 launched the CIECAM02 color appearance model and determined it as recommendation for industrial applications. In this paper, we review the situation and the latest theoretical research progress about CIECAM02 and discuss the main theoretical issues from three aspects , uniformity, model defects, prediction improvement, finally we analyze its shortcomings and put forward the problem to be solved and some research directions.

Abstract: By adding ZrO₂ and Y₂O₃ powder blend into the thermit, large bulk Al₂O₃/ZrO₂ (Y₂O₃) eutectics were prepared by combustion synthesis under high gravity, and the influences of high gravity on microstructures, crystal growth and properties of the materials were also discussed. The XRD patterns showed that the introduction of high gravity field did not change phase constitution of the ceramics, and the ceramic matrix was mainly composed of α-Al₂O₃, t-ZrO₂ and m-ZrO₂. SEM images and EDS analyses showed that with increasing high gravity level, the morphologies of the ceramic microstructures transformed from the cellular eutectics to the rod-shaped colonies, and volume fraction and aspect ratio of the rod-shaped colonies increased while the rod-shaped colonies were refined; as the high-gravity field was larger than 200g, the microstructures of composite ceramics developed as the randomly-orientated rod-shaped colonies with a symmetrical triangular dispersion of tetragonal ZrO₂ fibers of 300nm in the average diameter. Relative density, hardness, flexural strength and fracture toughness simultaneously reached the highest values of 98.6%, 18.6GPa, 1248MPa and 15.6MPa·m^1/2 as the maximum high-gravity level of 250g was achieved. The increases of relative density and hardness of the ceramics with the high-gravity level are attributed to the acceleration of gas-escape from ceramic melts and the elimination of shrinkage cavity in the ceramics. The increase in fracture toughness results from the enhancement of the coupled toughening mechanisms while the increase in flexural strength comes from the refinement of the microstructures, the decrease of critical defect size and the achievement of high fracture toughness.

Abstract: 70% Nylon 6 fiber and 30% low melting polyester fiber were manufactured into nonwoven fabrics, after which the nonwoven fabrics and Nylon 66 grids were needle-punched and heat-treated, forming the Nonwoven/ Nylon 66 grid composite fabrics. The optimum parameter for heat treatment was 150°C for 5 minutes, improving the mechanical property of the composite fabrics. Subsequently, with a fixed pick-up ratio of 200%, two waterborne PU resin (SE-5030 and SE-5070) with 0, 5, 10, 15, 20, and 25 wt% of cross-linking agent were used, offering the impregnation for Nonwoven/ Nylon 66 composite fabrics. After impregnation, the Nonwoven/ Nylon 66 grid composite fabrics were measured with drop tower stab testing, quasistatic stab testing and tensile strength testing. SE-5030 contributed greater tensile strength to the composite fabrics (1129.5 N in cross machine direction (CD) and of 816.4 N in machine direction(MD)); however, SE-5070 offered the composite fabrics the optimum stab-resistance strength of 69.9 N.

Abstract: Stainless steel (SS) blended yarns with electromagnetic interference (EMI) were made into woven fabrics, after which the fabrics were evaluated with electromagnetic shielding effectiveness (EMSE). Parameters of laminated angle and the lamination number layers affected the fabrics’ EMSE differently. In addition, density of unidirectional SS yarns affected EMSE in frequency range of 200 to 500 MHz , so as the density of cross SS yarns on a frequency over 1000 MHz.

Abstract: A series of novel copolymers poly (AOBDA-co-DNMMA)s containing 2-Allyloxy-N-benzyl- idene dodecylamine (AOBDA) and 1.4-dioxaspiro[4.4] nonane-2-methyl methacrylate (DNMMA) were synthesized. The copolymers could form stable condensed monolayer at air/water interface and be transformed onto solid substrates successively. Positive-tone patterns with the resolution of 0.75 μm of the copolymers Langmuir-Blodgett (LB) films with 40 layers were obtained by deep UV irradiation, followed by developing in acetone. The etched gold patterns with resolution of 0.75 μm were also obtained, showing that the copolymer has enough resistance to wet etching suitable for fabricating photomask. The mechanism of photolysis was also investigated by UV, IR and GPC.

Abstract: First-principles simulation was carried out to study the phase transformation of vanadium doped TiO₂ from anatase to rutile based on Ti5O10 cluster model. The Ti5O10 cluster models of anatase and rutile and corresponding V⁴⁺ isomorphous replaced cluster models were calculated to study the change of total energy, the ways of angular distortion, the change of frontier orbitals and the Ti⁴⁺ in the model preferentially substituted by V⁴⁺. The calculation results reflect that the V₂O₄ species, which has a rutile-like structure, can promote the phase transition from anatase to rutile. The single α electron in Ti4VO10 cluster model makes change to the frontier orbitals and the uneven contribution of electrons in valence shell may be the force driving the angular distortion in anatase lattice to rutile-like structure.

Abstract: Orthogonal tests are designed for hybrid fiber reinforced concrete. Bending toughness of hybrid fiber reinforced concrete, with the substrate intensity C30, the quantity of the volume for the steel fiber dosage 0~1.5% and polypropylene fiber dosage 0~0.3%, are studied. The results show that the hybrid fibers significantly improve the toughness of the concrete matrix. When the dosage reaches to a certain number, the affection of fiber toughness is decreased. Based on the test results the best dosage of hybrid fibers which is the steel fiber 1% mixed with 0.1% polypropylene fiber is recommended.

Abstract: Tool wear experiments in turning titanium alloy Ti6Al4V in the solution-treated and aged condition were carried out; the influence rules of cutting parameters such as cutting speed, feed rate and cutting depth on the tool life were obtained. Experimental formula of tool wear was regressed based on multi-variable linear regression analysis, it could predict tool life under certain conditions.