Corrosion behaviors of Cr2AlC/α-Al2O3 composites in 3.5 wt. % NaCl aqueous solution

Cr₂AlC and its composites containing α-Al₂O₃ (6.1 and 15.2 wt %) were prepared by hot pressing and their corrosion behaviors in air-saturated 3.5 wt % NaCl aqueous solution were investigated by electrochemical testing methods. It was revealed that the secondary phase of Al₂O₃ particles mainly distributed along grain boundaries of Cr₂AlC matrix. The potentiodynamic polarization measurements showed that the corrosion current densities of these Cr₂AlC composites were lower than that of the pure Cr₂AlC. The Aluminum in Cr₂AlC was prone to be attacked more easily. When immersed at open circuit potential (OCP), Al readily slipped out from Cr₂AlC matrix into NaCl solution in the form of dissoluble species. But in the case of polarization, regardless of potentiostatic polarization or potentiodynamic polarization, more de-intercalated Al, reacted with the electrolyte to form corrosion products of Al₂O₃ and/or AlOOH and deposited on the sample surface. For Cr₂AlC/α-Al₂O₃ composites, the presence of Al₂O₃ weakened the corrosion along grain boundaries by partly blocking the permeation of electrolyte and inhibiting the anodic dissolution process.     

Molten salt synthesis of MAX phases in the Ti-Al-C system

The molten salt method was used to synthesise the MAX phase compounds Ti₂AlC and Ti₃AlC₂ from elemental powders. Between 900–1000?°C, Ti₂AlC was formed alongside ancillary phases TiC and TiAl, which decreased in abundance with increasing synthesis temperature. Changing the stoichiometry and increasing the synthesis temperature to 1300?°C resulted in formation of Ti₃AlC₂ alongside Ti₂AlC and TiC. The type of salt flux used had little effect on the product formation. The reaction pathway for Ti₂AlC was determined to be the initial formation of TiC_1-x templating on the graphite and titanium aluminides.     

MAX3100在80C196串口扩展中的应用

介绍采用新型的UART器件MAX3100为Intel单片机80C196扩展串口，给出了硬件设计和软件编程，并对关键技术进行了说明。     

双电池系统电源选择器MAX1773/1773A

MAX1773／MAX1773A是用于双电池系统的电源选择器，它允许外部控制器去管理双电池组、适配器输入、电池充电器和系统负载所需的电源连接。文中介绍了MAX1773／1773A的特点、引脚功能、内部结构和工作原理，给出了MAX1773/MAX1773A的典型工作电路。     

16位A/D转换器MAX1166的原理及应用

MAX1166是美国MAXIM公司生产的逐次逼近型16位低功耗模数转换器 ,该转换器内带4.096V精密参考源 ,同时具有并行数据输出接口。文章介绍了该模数转换器的特性、功能及实际应用电路。     

16位串行模数转换器MAX1132的特性及应用

MAX1132是美国MAXIM公司生产的16位串行模数转换器，文章介绍了MAX1132的工作原理、接口特点及使用方法，给出了它在数据采集系统中的硬件电路和软件程序。     

闭路电视监控系统中矩阵控制器的设计

以 6 4× 16矩阵控制器为例 ,介绍了闭路电视监控系统中矩阵控制器的设计方法 ,矩阵控制器的主要功能 ,以及视频矩阵切换芯片MAX4 35 8的性能特点及使用方法 ,概括提出了在软、硬件设计时应注意的几个问题     

采用注视控制器实现复杂运动的仿真

注视控制器是3DS MAX软件的众多控件之一，它能使多个物体彼此间产生运动约束。通过使用注视控制器功能，笔者成功制作出八足爬壁式仿生机械昆虫的运动场景动画，并使该仿生机械昆虫各足的行走动作符合机械零件作平面复杂运动时所应遵守的正确运动规律。由此证明，3DS MAX软件注视控制器对正确模拟特殊机械装置的复杂运动可产生极大作用。     

基于MAX120的峰值电压检测及其与CPLD的接口

介绍了一种性能良好的A／D转换器MAX120，详细阐述了基于MAX120的数字式峰值电压检测器，并示出了其逻辑功能的Verjlog—HDL描述和与CPLD的接口电路，最后给出了在窄脉冲测试源作用下的实测结果。     

宽频带函数波形产生器的研制

本文介绍以ＭＡＸ０３８为基础而研制的宽频带函数波形产生器，它可以产生２￣２×＾７Ｈｚ频率范围的正弦波、三角波、锯齿波和矩形波以及与它们同步的ＴＴＬ脉冲信号。