新型陶瓷刀具的发展与应用

回顾了陶瓷刀具的发展简况及其意义,重点介绍了Si3N4基和TiCN基复合陶瓷刀具的研制、性能和应用.复合Si3N4陶瓷刀具有较高的耐磨性和抗冲击性,特别适合于各类铸铁件的粗精加工,也能进行铣削、刨削等冲击力很大的加工,其切削效率可提高3～10倍;复合TiCN金属陶瓷刀具具有很高的硬度和耐磨性,特别适合于各类高硬高强钢(如淬硬钢等)的加工,可对高硬材料实现"以车代磨"干切削,免除退火工艺和冷却液,大幅度提高生产效率.新型复合陶瓷刀具已经在我国冶金、水泵、矿山机械、轴承、滚珠丝杠、汽车、军工等十几个行业得到应用.     

热处理对AlN·Al_3Ti/ZL101原位复合材料力学性能的影响

研究了不同热处理制度对AlN.Al3Ti/ZL101原位复合材料力学性能的影响。结果表明,该复合材料中增强相尺寸为亚微米级,最佳的热处理制度为:530℃×5h固溶,60～80℃水中淬火,160℃×14h时效。在最佳热处理制度下,复合材料的抗拉强度、硬度、伸长率分别为345MPa、108HB和3.5%,均较铸态有较大幅度提高。     

耐磨低合金铸钢的研制

加入稀土合金及多种合金元素研制的耐磨合金铸钢,经过热处理工艺后,硬度和韧度高,耐磨性能好,成本低,在中、低冲击功工况下是高锰钢和高铬钢的理想替代材料.     

钛合金的表面渗氧强化研究进展

一种简单而有效的被称之为钛合金表面渗氧强化处理的技术在最近几年得到发展。介绍了渗氧强化机理及几种渗氧强化处理技术,包括氧扩散（OD）、热氧化（TO）等离子体渗氧和激光渗氧;最后对渗氧强化处理的前景作了展望。     

铝板热轧机的液压AGC控制

介绍了铝板热轧机液压AGC系统的控制原理,以及AGC的几种控制方式。     

Effects of Sc and Mn on microstructures and mechanical properties of Mg-Gd alloy

Two alloys of Mg-12.4Gd and Mg-12.5Gd-0.8Sc-1.4Mn were prepared. Hot extrusion and T5 heat treatment were conducted, and then the mechanical properties of the two alloys were tested at room and high temperatures. The effects of Sc, Mn on the microstructures of Mg-12.4Gd were investigated by optical microscopy, scanning electron microscopy and transmission electron microscopy. The results demonstrate that after hot-extrusion the alloying with Sc, Mn can efficaciously refine the grains of Mg-12.4Gd alloy; and increase the elongation at room and high temperatures after T5 heat treatment. But the strength at high temperature is not obviously improved.     

某发动机高压二级涡轮叶片断裂失效分析

某发动机在试车时高压二级涡轮叶片全部断裂.本文对叶片断口特征、高压二级涡轮外环内壁的损伤情况进行了观察,对叶片的显微组织进行了检查,分析了断裂性质和形成原因.结果表明,高压二级涡轮叶片的断裂为过载断裂,叶片的断裂与材质或加工无关.叶片的断裂是由于叶片与涡轮外环发生了严重摩擦所致.导致叶片与外环发生严重摩擦的原因可能是叶片承受了短时超温,导致叶片发生高温伸长.同时,短时超温导致的叶片高温强度下降对断裂也起到了一定的促进作用.     

Preparation of flee-standing diamond films for high frequency SAW devices

Free-standing diamond films were prepared by hot filament chemical vapor deposition （HFCVD） method under different conditions. Inter-digital transducers （IDTs） were formed on the nucleation sides of free-standing diamond films by photolithography technique. Then piezoelectric ZnO films were deposited by radio-frequency（RF） reactive magnetron sputtering to obtain the ZnO/diamond film structures. Surface morphologies of the nucleation sides and the IDTs were characterized by means of scanning electron microscopy （SEM）, atomic force microscope （AFM） and optical microscopy. The results indicate that the surfaces of nucleation sides are very smooth and the IDTs are of high quality without discontinuity and short circuit phenomenon. Raman spectra show the sharp diamond feature peak at about 1 334 cmI and the small amount of non-diamond carbon in the nucleation side. X-ray diffraction （XRD） patterns of the structure of ZnO/diamond films show a strong diffraction peak of ZnO （002）, which indicates that as-sputtered ZnO films are highly c-axis oriented.     

碳酸钙的等离子体表面改性

利用等离子体对碳酸钙粉体填料进行表面处理是新发展的一种填料改性技术.从等离子体表面改性机理、等离子体改性碳酸钙的特性及应用等方面进行了详细的论述.     

原位增强体Al3Ti形成热力学及合金元素对其形貌影响

通过热力学方法分析了Al3Ti生成反应进行的可能性,探讨了Al3Ti/ZL101原位复合材料中增强相Al3Ti的形成机制,确定了增强相Al3Ti的存在及合金元素对形成亚微米尺寸增强相的影响,测定了原位复合材料的常温力学性能.研究结果表明:原位生成Al3Ti反应自发进行的趋势很大;增强相Al3Ti的形貌和尺寸受合成反应所选原材料的影响,只有在合金元素硅存在的条件下,才能产生尺寸在0.5μm左右的增强相Al3Ti;原位复合材料的常温力学性能较基体都有一定程度的提高.