Advanced Materials Research Vols. 239-242

Abstract: In this paper, pass schedule calculation method for single-stand reversing cold rolling mill is introduced. Newton－Rapshon method is used to solve non-linear equations composed of each pass loads according to equal power rolling strategy. After the thickness of each pass is calculated, rolling parameters of each pass is obtained by modification. Based on the method pass schedule calculation procedure is developed. The practical application shows that calculation result of program is close to the actual data, and the speed and stability of the procedure can meet the requirement of on-line process control, so it is suitable for the single-stand reversible cold rolling mill.

Abstract: Three new hypercrosslinked polymers were used as solid phase extraction packings to enrich Chlortetracycline (CTC) in water. Through the comparison, the NDS-1 column has higher performance than the other two, almost the same as commercial columns HLB on the enrichment of the Chlortetracycline.

Abstract: Plasma electrolytic oxidation (PEO) of an 6061 Al alloy was accomplished in an electrolyte with sodium hexametaphosphate (10 g/L) and sodium silicate (10 g/L) Coatings were produced at four different current densities (4, 6, 8 and 10 A/dm²). Phase composition, morphology and tribological characteristics of the coatings were studied by X-ray diffraction (XRD), scanning electron microscope (SEM) and ball-on-disk friction testing. The results show that among the four ceramic coatings which were produced under four current densities, the coating produced under the current density of 8 A/dm² got the lowest wear rate with the value of 4.5 × 10^-5 g/m.

Abstract: Influence of frictional wear characteristics of the cast iron-cast iron friction pair were investigated in the Self-repairing Additive with different concentration by using MMU-5G end-face friction and wear testing machine. The capability of generating self-repair coatings on the cast iron tribo-surface was verified in the Self-repairing Additive. The surface images of friction pair and their chemical composition were detected by using SEM and EDS. The result indicates different concentration has a great influence on frictional wear characteristics of friction pair in the Self-repairing Additive. In the self-repairing Additive, the Self-repair coatings are not formed on the cast-iron worn surface; self-repairing Additive has remarkable effect on antifriction and wearing of cast iron.

Abstract: At four different temperatures, by potentiodynamic polarization curve, the inhibiting effect of dicyclohexyl thiourea (DCTU) on the corrosion behavior of 304L stainless steel in 2 M hydrochloric acid solution was investigated. The result indicated that DCTU acted as an efficient anodic inhibitor for the corrosion of 304L SS. Excellent inhibition efficiency was evident in the acidic solution and found to vary with temperature and concentration of the inhibitor. The adsorption of this compound on the 304L SS surface was found to obey Temkeins adsorption isotherm and the inhibition was governed by chemisorption mechanism. The deduced thermodynamic parameters of adsorption revealed a strong interaction and spontaneous adsorption of DCTU on the metal surface.

Abstract: A new thermosetting boric acid ester modifier containing unsaturated bonds (abbreviated TBCE) was prepared. Structure, hydrolytic stability, curing properties and and thermal properties of the boric acid ester were studied by FT-IR, DSC and TGA. The result indicated that the obtained boric acid ester was soluble in most common solvents and was easily processed. The thermogravimetric analysis of silicon-containing arylacetylene resin modified by TBSE (abbreviated MSAR) showed that char yield at 800°C was 87% under nitrogen and 49% under air, and T_d5 (temperature of 5% weight loss) were 570°C and 580°C respectively.

Abstract: A novel series of Pyridinium salts with rhenium group attached to the alkyl side chain, viz. [C_nPy][ ReO₄] (where C_nPy is the N-alkyl- pyridine cation and C_n=(CH₂)_n-1CH₃, n = 2-6), have been synthesized and characterized. The physicolchemical properties of the ionic liquids have been determined and estimated. The influence on physicolchemical properties by molecular structure was discussed.

Abstract: In order to improve and simplify the process of electroless Ni-P plating on AZ91D magnesium alloy substrate, pretreatment process and deposite time were optimized by orthogonal test, the plating morphology were analysed using Quanta 200 type scanning electron microscope. The bond between the plating and aluminum substrate were evaluated using method of water quenching and alternating bending test. The results show that good coating can be obtained on AZ91D substrate under the condition of the acid electroless Ni-P plating solution with pickling time of 40-50s, activated time of 10 min. And the good bond between the coating and AZ91D substrate was obtained.

Abstract: An interpenetrating polymer network was formed by blending of PLLA and PEG cross-linked β-CD to improve the toughness of PLLA, and the mechanical properties of PLLA composites were studied using tensile test. The PLLA composite samples exhibited a single glass transition and their T_g values decreased with increasing PEG/β-CD content, indicating that PLLA and PEG/β-CD are miscible. The PLLA composite samples aged at room temperature achieved the highest fracture strain (about 235%), about 40 times that of the original PLLA sample, while the Young's modulus was not seriously hampered.

Abstract: La³⁺/halogen (F^-, Cl^- and Br^-) co-doped TiO₂ was synthesized by alkoxide hydrolysis method. The prepared La³⁺/halogen TiO₂ photocatalysts with anatase phases and rutile phases were characterized with XRD, EDS, TEM and surface area analytic technology. Methyl orange was used as model pollutants to evaluate its visible light photocatalytic activity. The results showed that the co-doping of La³⁺ and halogen ions improved the surface area of TiO₂. Compared with 450°C and 650°C, La³⁺/Cl^- and La³⁺/Br^- co-doped TiO₂ calcined at 550°C exhibited much higher photocatalytic activity. The optimal doping ratio of La³⁺/F^-, La³⁺/Cl^- and La³⁺/Br^- was 0.4, 0.6, and 0.5 ((wt%)/(wt%)), respectively. Moreover, the degradation ratio of methyl orange on La³⁺/halogen co-doped TiO₂ with the optimal ratio were all higher than the maximum degradation ratio on La³⁺, F^-, Cl^- and Br^- doped TiO₂ prepared by the same method.