Direct electroless Ni-P deposition on AM50 magnesium alloy from sulfate bath

A bright electroless Ni-P deposition on AM50 magnesium alloy in a sulfate plating bath was proposed by using direct plating process with non-chromate pretreatment. The electroless Ni-P plating on AM50 magnesium alloy has an admirable appearance and good adhesion. The results indicate that the electroless Ni-P deposition with non-chromate pretreatment has better adhesion than that of zinc immersion coating. Anodic polarization curves indicate that the electroless Ni-P deposition obtained from the sulfate bath has similar corrosion-resistance to that obtained from basic nickel carbonate bath. The deposition process generates less pollutant by a non-chromate plating bath and is suitable for the magnesium alloys manufacture because of its low cost. The hardness of the electroless Ni-P plated AM50 is about HV 720.6 and HV 969.7 after heat treatments at 180℃ for 2 h. The wear resistance of Ni-P plated magnesium alloy specimens is about 5 to 9 times as high as that of bare magnesium alloys.     

Effect of Reactor Ambient Pressure on the Morphology of Spray Dried Magnesium Sulphate Powders

The effect of reducing the reactor air pressure on the morphology of spray dried magnesium sulphate powders is investigated, experimentally. A reactor, capable of drying and pyrolyzing solution sprays at low pressures, is designed and manufactured. A vibrating mesh nebulizer is employed to generate the spray. Four different pressures, starting from 60 Torr to the atmospheric pressure, and two different reactor air temperatures of 130°C and 420°C, are considered. In addition, two different concentrations of magnesium sulphate solutions are tested. The results are explained based on the effect of reactor air pressure on the droplet evaporation rate.     

Studies on spray pyrolyzed molybdenum trioxide thin films

Semiconducting molybdenum trioxide thin films have been prepared by employing simple and inexpensive spray pyrolysis technique. Films are found to be polycrystalline in nature with hexagonal phase. Optical band gap energy (direct) and room temperature electrical resistivity are of the order of 2·9 eV and 10⁸ ohm-cm, respectively. These films exhibit cathodic electrochromism.     

半导体元件清洗技术浅谈

随着社会的进步和科学技术的迅猛发展,对洗净技术的要求也越来越高。清洗方式多种多样,但最主要的是突出在喷射清洗和超声波清洗两大方面,应用于全国各行各业,并且也得到了明显进步。     

锥形凸台成形的一种叠加滑移线场力学模型

分析了锥形凸台在不同体积成形工艺中的成形机理，基于模块化思想将锥形凸台的成形过程划分为挤压成形与角部充满两个特征时段；将上述两个特征时段的滑移线场力学模型有机联结，构建了锥形凸台成形过程的一种叠加滑移线场力学模型；介绍了叠加滑移线场力学模型的应力场与变形力的求解方法。该模型丰富了金属体积成形过程的特征单元库，可套用于局部成形的应力场与变形力求解，实现局部成形的模具优化设计。     

烧结机双层插板式卸灰阀的研制

烧结机双层卸灰阀由蘑菇头式改为电液推杆插板式，有效地解决了系统卸料及漏风问题，实现了控制自动化，提高了设备作业率，改善了岗位环境。     

轻质喷涂料的研制

研究了轻质骨料种类，加入量和添加剂等对轻质喷涂料技术及使用性能的影响。并将研制的轻质喷涂料成功地应用于武钢炼铁厂高炉管内壁的喷涂。     

Bruchanalyse an Hohlgläsern

Failure analysis of hollow glasses The failure analysis is very important to clarify damages of hollow glasses. Damages of glass bottle through over pressure are very often linked with damages to persons. This is the reason why the causal research is from particular importance. Different surface characteristics of glass fragments as well as the fracture pattern give hints to the direction of the crack, the stress just before breakage and the reason of stress. A reconstruction of the bottle is a further helpful instrument for cause studies. The difference of the various characteristics of the surface will be explained. Further on there will be discussed different reasons and mechanism of fracture.     

喷雾沉积快速凝固技术的发展与展望

喷雾沉积是制取大体积快凝材料的一种新工艺。本文综述了它的产生和发展，概述了其基本原理和过程控制。对该领域今后的发展动向，提出了一些新看法。     

定向凝固空心叶片制壳工艺的改进

分析了在先进发动机定向凝固空心叶片熔模精密铸造生产中出现两种缺陷的性质和产生原因，从壳型制造工艺方面提出了改进措施，提高了叶片合格率。