电弧超声焊缝跟踪的试验研究

利用声发射探头接收的电弧超声信号进行焊缝跟踪检测。结果表明：对称位置接收到的声发射信号的相位差和幅值差可以作为电弧超声焊缝跟踪的依据。     

Formation and thermal stability of amorphous Ni-Mo-P alloys

The experimental researches on the chemical deposition of Ni-Mo-P amorphous alloys were carried out by adding Na2 MoO4 into acidic solutions. The optimum technology conditions were obtained by orthogonal design experiments. The structures and the relationship between compositions and their thermal stability were studied by energy spectrum (EC), scanning electron micrograph and X-ray diffraction spectrum. Compared with Ni-P amorphous alloys, the Ni-Mo-P amorphous alloys have high crystallization temperature and thermal stability, and the hardness reaches its peak when the annealing temperature is 500 ℃. With the increase of the heat treatment temperature, the surface morphology of the alloys changes.     

Preparation of modified LiMn2O4 by solid-state reaction

Modified lithium manganese oxides were prepared by solid-state reaction of LiMn2O4 and LiCoO2 as raw materials. A study was carried out by TG-DSC,XRD, DSC and electrochemical to analyse the reaction process and structural characterization of products. The results show that the LiMn2O4 reacts chemically with LiCoO2 at high temperature. All of Li and partial Co atoms can insert into the LiMn2O4 crystal lattice and a newly formed spinel phase-modified LiMn2O4 was obtained. The distribution of Co content is even in modified LiMN2O4 compound. The modified LiMn2O4 compound exhibits improved cycling stability at room and elevated temperature in comparison with the pure LiMn2O4.     

Mechanical properties and microstructure of Ti-6Al-4V compacts by metal injection molding

Ti-6Al-4V compacts were fabricated by metal injection molding(MIM). Influence of vacuum sintering time on mechanical properties and microstructure of the sintered compacts at 1 260 ℃ were investigated. The experimental results show that the compacts sintered at 1 260 ℃ for 3 -6 h, which was made from hydrogenation-dehydrogenation(HDH) powder(average particles size is 45 μm), have a relative density of 95.6%- 96.7%, ultimate tensile strength of 648 - 686MPa and 0.2% yield strength of 526 - 615MPa; but a lower elongation(＜4%) and that the compacts sintered at 1 260 ℃ for 2 - 6 h, which was made from 90% gas-atomized powder(average particles size is 32.5 μm) and 10 % HDH powder, have higher relative density(＞95 %), ultimate tensile strength of 800 -848MPa,0.2% yield strength of 712 - 762MPa and high elongation (7.4%- 9.5%). When the sintering time is increased,porosity decreases and microstructure of sintered products changes from equiaxed to typical Widmanstatten, the average sizes of prior β grains, α colonies and α phase thickness in the β grains increase accordingly. After HIP treatment,pores obviously become less, microstructure of alloy is refined and mechanical properties are greatly improved.     

高速压力机滑块液压过载保护结构设计与分析

介绍了高速压力机的一种滑块液压过载保护装置，并结合本厂高速压力机产品的开发实例，对装置结构进行了分析。     

Modification mechanism of cerium on the Al-18Si alloy

The effect of the rare earth cerium （Ce） on the hypereutectic Al-Si alloy under different casting states have been studied by optical microscope and quantitative image analysis. It is found that the size and the quantity of primary silicon in castings decrease with the increase of added Ce in the melt. Meanwhile primary silicon changes from branched shape to fine facetted shape. Although the modification on eutectic silicon in castings also improves with the increase of added Ce in the melt, the effect of modification on eutectic silicon away from primary silicon is more obvious than that on eutectic silicon close to primary silicon. The modification mechanism was analyzed in detail by means of scanning electron microscope equipped with energy dispersive analysis of X-ray and thermodynamics analysis, which included the analysis on the change in standard Gibbs energy of reaction and reaction equilibrium.     

基于柔性工程数据库的CAD与PDM系统集成方法研究

分析了信息集成的各种方式 ,研究了当前CAD与PDM系统集成过程中面临的实际问题 ,提出了以柔性工程数据库为基础的CAD与PDM系统集成的解决方法 ,并且描述了系统的框架结构。     

2A12铝合金φ550mm圆铸锭光亮晶粒的防止

2A12铝合金Φ550mm圆铸锭在挤压后，发现有光亮晶粒而导致挤压棒材报废。通过对铸锭光亮晶粒产生原因的分析，采取了防止其产生的措施，最终避免了光亮晶粒冶金缺陷。     

斜销抽芯式压铸模设计过程与技巧

为了提高斜销抽芯式压铸模设计的质量和效率，对传统的设计过程进行了优化。利用压铸模上主要零件的相互联系，从压铸模型腔人手，向外逐步设计。总装图中视图的设计顺序为：主剖视图、主视图、辅助剖视图、局部剖视图。然后设计辅助零件和全部零件上的细节。对各零件的设计要点和技巧也作了一定的介绍。经过实践检验，效果良好。     

3种分散剂对ITO浆料稳定性能的影响

选用3种分散剂(聚乙烯吡咯烷酮、柠檬酸三铵、β-丙氨酸),通过球磨分散法制备ITO浆料,通过考察球磨分散时间和分散剂量对ITO浆料稳定性能的影响,分析比较不同分散剂对浆料稳定性作用,并探究其分散机理。结果表明:3种分散剂分散机制均为静电和空间位阻稳定作用;在相对ITO粉体质量比为5%、最佳球磨分散时间为48 h时,在15 d内ITO浆料的RSH可维持在10%以内;3种分散剂对ITO浆料稳定性的影响由强至弱的顺序为:聚乙烯吡咯烷酮>β-丙氨酸>柠檬酸三铵,与其在溶液中酸碱性强弱顺序一致,其中聚乙烯吡咯烷酮的分散效果最好。