Applied Mechanics and Materials Vol. 686

Abstract: The properties of the heat-treatable aluminum alloys are enhanced by solution heat treatment and controlled ageing. The mechanical properties become stable with natural ageing at room temperature within a few days for some heat-treatable alloys, especially 2XXX series, considerable changes of the properties occur even after many years for some of them. Solution heat treatment of AA 2024 is very critical and sensible and therefore it should be carefully conducted. In this research, the effects of the solution temperature, soak time, quenching delay and heating rate of AA 2024 on the mechanical properties and the formability index (limiting dome height) were investigated in order to determine optimal solution heat treatment condition. Mechanical properties were determined and limiting dome heights of the formed parts were measured for all the situations and optimal solution heat treatment conditions were determined by using ANOVA method.

Abstract: In this study, the cutting performance of ceramic insert was investigated in terms of surface roughness and tool wear in turning of hardened PMD 23 powder metallurgical (PM) steel. The turning tests were performed with three different cutting speeds, feed rates and depth of cuts in dry cutting condition. Analysis of Variance (ANOVA) was performed in order to determining of the effect of cutting parameters on the average surface roughness (R_a). The experimental results and indicated that the feed rate was most significant parameter on changes in R_a. Furthermore, images of cutting insert used in turning tests were taken using Scanning Electron Microscope (SEM) for determining of the wear types and its mechanisms.

Abstract: Taking 7-APCA as raw materials, in a suitable solvent system, to get 7-APCA alkali solution with the alkali reaction. The paper takes p-hydroxyphenyl glycine dane salt as raw material, to made the corresponding reagent in phthalic anhydride. Forming DMF salt of cefprozil by reaction of 7-APCA alkaline solution and the mixed anhydride. The transformation of methanol, water, and water purification to get cefprozil monohydrate. The total yield was 63%. The chemical structure of cefprozil were confirmed by IR, 1h-nmr. Product quality in line with national pharmacopoeia requirements.

Abstract: Rapid prototyping technology can greatly improve the actual processing industrial prototype; this paper introduces the main principle, characteristics and technology of rapid prototype manufacturing. The current rapid prototype manufacturing products and production problems are analyzed. Because of the direct metal forming process have the characteristic of point by point, surfacing with stack molding manufacturing layer by layer, so it is suitable for complex shape parts two-dimensional or three-dimensional functionally gradient materials manufacturing.

Abstract: This paper designed and synthesized a series of different chain length of phthalonitrile-terminated oligo (phthalazinone imide), it has good water solubility, and can be under normal atmospheric pressure to form the s-triazine rings-containing thermosetting oligo (phthalazine imide). Compared with the traditional thermosetting resin, the resin has the advantages of high temperature resistance, high strength, flame retardant, resistance to chemical corrosion.

Abstract: This paper makes use of various synthetic methods and analysis techniques, from material preparation, structure characterization of the electrochemical performance, we systematic study lithium iron phosphate, preparation electrode materials with good performance. This paper mainly aims at the two fatal drawbacks restrict the performance of LiFePO₄ cathode material, namely, low electron conductivity and lithium ion diffusion rate low, take the material particle, particle deposition on the surface of carbon conductive layer and Mg²⁺ ion doping and other measures to modify it to explore, in order to improve the electrochemical performance of LiFePO₄ cathode material.

Abstract: This paper covers the safety requirements and inspection methods for insulating components used in electrical accessories by an analyzing the properties of the insulating components used in electrical accessories based on the standard of IEC 60884.

Abstract: This paper collected 18 soil samples in the Chin-sha River basin, and analyzed residues of organochlorine pesticides (OCPs) in soil using gas chromatographic method, revealing the organochlorine pesticide residues, the distribution and sources in the river basin. The results show that, the relatively high sampling residues of organochlorine pesticide distribute in the industrial area. The composition and characteristics of organic chlorine pesticide show that the organochlorine pesticide residues in soil mainly come from the historical use. Compared with the domestic similar research, residual organochlorine pesticides in Chin-sha River basin were lower.

Abstract: This paper introduces the method of porous ZnO microspheres by sodium citrate assisted hydrothermal synthesis with a mild, economy: first, basic synthesis globose precursor of Zinc Carbonate Hydroxide, then followed by thermal decompose the precursor to obtain porous Zinc Oxide microspheres. The morphology and structure of the precursor and synthesized porous microspheres were characterize by a series of methods, and did a series of experiments by changing dosage and reaction time of the sodium citrate and urea, finally the paper discussed the formation mechanism of porous ZnO microspheres.