汽车半轴的热挤压成形工艺

介绍了汽车半轴的热挤压成形新工艺及模具设计要点.     

Performances of electrically heated microgroove vaporizers

An electrically heated microgroove vaporizer was proposed. The vaporizer mainly comprised an outer tube, an inner tube and an electrical heater cartridge. Microgrooves were fabricated on the external surface of the inner tube by micro-cutting method, which formed the flow passage for fluid between the external surface of the inner tube and the internal surface of the outer tube. Experiments related to the temperature rise response of water and the thermal conversion efficiency of vaporizer were done to estimate the influences of microgroove＇s direction, feed flow rate and input voltage on the performances of the vaporizer. The results indicate that the microgroove＇s direction dominates the vaporizer performance at a lower input voltage. The longitudinal microgroove vaporizer exhibits the best performances for the temperature rise response of water and thermal conversion efficiency of vaporizer. For a moderate input voltage, the microgroove＇s direction and the feed flow rate of water together govern the vaporizer performances. The input voltage becomes the key influencing factor when the vaporizer works at a high input voltage, resulting in the similar performances of longitudinal, oblique and latitudinal microgroove vaporizers.     

Accu—Roll轧管机组主减速机输出轴联轴器大过盈量装配

介绍了采用油温加热装配工艺,实现Accu-Roll轧管机组主减速机输出轴联轴器大过盈量装配。     

铝电解用TiB_2阴极涂层固化、炭化的升温制度

采用DTG ,DDTA等热分析手段 ,研究了高温固化、炭化过程中 ,铝电解用TiB2 阴极涂层糊料的质量和能量的变化速率 ,制定了涂层的变速固化、炭化升温制度 ;在此基础上 ,研究了升温制度对TiB2 阴极涂层性能的影响。结果表明 :变速升温制度优于匀速升温制度 ,采用变速固化、炭化升温制度所制备的涂层形变小、无裂纹 ,其抗拉强度达 3.13MPa,电阻率为 2 3.2 μΩ·m ;而采用升温速度为 10 .3℃ /h的匀速固化、炭化升温制度制备的涂层形变大、裂纹多 ,抗拉强度小 (2 .6 9MPa) ,电阻率大 (2 8.6 μΩ·m)。     

Effects of temperature and blank holding force on biaxial forming behavior of aluminum sheet alloys

Biaxial forming behavior is investigated for three aluminum sheet alloys (Al 5182 containing 1% Mn (5182+Mn), Al 5754, and 6111-T4) using a heated die and punch in the warm forming temperature range of 200–350 °C. It is found that, while all three alloys exhibit significant improvement in their formability compared with that at room temperature, the non-heat-treatable alloys 5182 + Mn and 5754 give higher part depths than that of heat-treatable 6111-T4. The formability generally increases with decreasing BHP (BHP), but increasing the forming temperature and/or BHP minimizes the wrinkling tendency and improves the forming performance. The stretchability of the sheet alloys increase with increasing temperature and increasing BHP. For the alloys and forming conditions involved in the current study, the formability, measured in terms of part depth, comes mainly from the drawing of metal into the die cavity, although stretching effects do influence the overall forming behavior. The optimum formability is achieved by setting the die temperature 50 °C higher than the punch temperature to enhance the drawing component. Setting the die temperature higher than the punch temperature also improves the strain distribution in a part in such a manner that postpones necking and fracture by altering the location of greatest thinning.     

利用微波介电加热和微波干燥水解法制备TiO2微粒

利用微波介电加热和微波干燥条件下TiCl4直接水解的方法制备出平均尺寸为40m，粒径分布窄，均为球形且形态均一，团聚较少，金红石型的TiO2纳米粒子，其内部品粒平均大小为17nm。而传统加热和干燥条件下形成的纳米微粒平均为60nm，粒经大小不均一，形态较不规则，团聚严重。微波加热和干燥方法具有清洁、快速均匀高效、环境友好的优点，推广前景良好。TiCl4水解法经济便利，适于工业化生产。     

关于煤炭硫分分级的探讨

根据国家质量技术监督局的计划安排,国家标准GB／T15224－1994《煤炭质量分级》需要修订。本文主要讨论“煤炭硫分分级”方面的内容。     

自控温加热带的研制

研究了炭黑含量、辐照剂量以及体系共结晶性对以高密度聚乙烯/乙烯 丙烯酸乙烯酯共聚物为基材的自控温加热带电阻率及电热稳定性能的影响,以及加工条件和后处理工艺对材料电性能的影响。结果表明,50～80kGy的辐照剂量为本体系提供优异的电热稳定性,适当的加工及后处理工艺能大大改善该体系的导电性。     

6m大容积焦炉烘炉实践与体会

介绍了 6 m大容积焦炉由冷态到转入正常加热温度的烘炉操作过程中 ,按照一定的升温曲线 ,通过对焦炉热工和炉体膨胀的科学管理 ,确保新建焦炉顺利由冷态过渡到生产状态。     

渠首水位实时调控模型——以船行灌区一支渠为例

很多大中型灌区在输配水过程中存在水位衔接不当的问题,加之田面高程存在起伏,使得灌溉时往往存在部分田面不能上水或受淹等问题。本文提出了空间灌溉率的概念,并利用GIS的三维分析功能研究了其与渠道渠首水位之间的关系。分析表明,空间灌溉率与渠首水位之间的关系符合Logistic曲线;针对船行灌区一支渠,得到该Logistic曲线的参数,并确定了一支渠渠首和干渠渠首不同空间灌溉率所需的水位,为灌区水位实时调控提供基础数据。