采用化学成分、金相检测、涂层厚度、维氏硬度、能谱及XPS表面分析等方法,对304不锈钢零件表面TiAlCN涂层变色原因进行分析.304不锈钢零件表面TiAlCN涂层变色主要在孔区域,表面有约20 nm的界面层,界面层硬度偏低且涂层厚度不均匀,有脱落;同时涂层中钛原子有氧化、铝元素含量偏高、碳元素含量偏低,使膜层结合力下降,最终导致TiAlCN涂层表面脱碳氧化,从而出现发白、发紫现象.

采用扫描电镜观察、化学成分及金相检验等方法对高强度螺栓断裂的原因进行了分析.结果 表明,螺栓基材的芯部显微组织中含有一定量的贝氏体,降低了零件的强度,导致在承受外力作用时,过早在应力集中的螺栓头根部产生疲劳裂纹.在交变应力和腐蚀介质的共同作用下,造成疲劳裂纹不断向内扩展.当个别螺栓的有效承载截面减小至强度不足时引起断裂,剩余螺栓承受载荷加大,加速产生腐蚀疲劳断裂.

在建筑工程施工期间,经常会遇到对钢结构运行工况判断的状况,继而协助工程师能采用适宜的方法处理钢结构,而最常见的问题是对钢结构工作应力检测.文章主要阐述了有损与无损检测法的应用要点及技巧做出分析研究,并总结了钢铁结构件工作应力检测过程中的应注意的问题.希望与技术人员共同分享经验,促进用钢铁结构件在建筑工程施工进程中的有效发挥.

滑石瓷在高档餐具和无线电行业有很高的潜在价值,但是其烧结范围较窄,烧成操作困难.本文采用模压成型和常压烧结工艺制备三组不同配方的滑石瓷,对比研究这三组滑石瓷的性能和内部结构,分析添加剂氧化锌对拓宽滑石瓷烧结范围的作用.质量烧减率、烧成收缩等物理性能测试表明在相同的烧成制度下,添加氧化锌可减小滑石瓷性能的质量烧减率、烧成收缩;XRD分析和扫描电镜观察表明添加氧化锌可以减少滑石瓷的晶粒尺寸和气孔数量.因此,氧化锌可起到拓宽滑石瓷烧结范围、改善其性能的作用.

介绍了太阳能吸收涂层的评价方法,从提高吸收率、降低发射率、提高耐候性等角度综述了近年来使用涂料法、电镀法、氧化法、喷涂法、化学溶液法等典型非真空方法制备太阳能吸收涂层的研究成果。

Analysis was performed on the black spot on the surface of electroplated spanner,using metallography,SEM and EDS.The results showed that the reason of the appearance of black spot was because the plated layer was too thin which reduce the corrosion resistance and led to electrochemical corrosion and formed penetration hole.

Failure analysis was performed on a crane bearing by means of SEM,metallographic examination and hardness testing methods. It′s found that the premature crack of the bearing occurred because of too much reticular carbide presence in the balls of the bearing and the low hardness of both the balls and the bearing ring.

The springs of the water pumping valve fracture after 6 months′ service.The means,such as chemical composition analysis, metallography and scanning electron microscope etc,were used to analyse the reason of fracture.The result indicated that the corrosion fatigue fracture is the main reason of the spring fail.

在实际工业应用中,对不同的产品表面粗糙度有不同的要求,因此,在利用表面处理技术对产品进行表面处理时,其对产品表面粗糙度的影响成为必须考虑的因素.采用微弧氧化技术,以LY12铝合金为试验样品,通过改变不同的微弧氧化功率,制备相应的铝合金陶瓷膜,分别对陶瓷膜进行SEM分析及表面粗糙度测量,得出铝合金陶瓷膜表面粗糙度随微弧氧化功率的变化曲线,研究了氧化功率对铝合金陶瓷膜表面粗糙度的影响.结果表明:微弧氧化功率对铝合金陶瓷膜表面粗糙度的影响非常明显,随着微弧氧化功率的提高,陶瓷膜粗糙度随之增大.并从机理方面进一步做了分析.

The concept of oxidation power was introduced to reveal the action of energy during the micro-arc oxidation process. Thus micro-arc oxidation aluminum oxide coatings were prepared on LY12 Al alloy substrate at various process parameters using a pulse power supply. The thickness and hardness of the resulting ceramic coatings formed at fixed pulse width and frequency but varied duration and oxidation power were measured, and the changing tendencies of the thickness and hardness of the ceramic coatings with the process parameters were discussed. It was found that the hardness and thickness of the ceramic coatings tended to increase with increasing micro-arc oxidation power at fixed oxidation duration and area, while the thickness of the coating tended to increase with increasing micro-arc oxidation time and decrease with increasing workpiece area in case the other process parameters were kept constant.