微小电偶腐蚀电流的准确测定

为了更多地获得电偶腐蚀的信息并揭示其本质规律，提出了电偶腐蚀试验实时监测模型。通过选用不同设备对试样的电偶腐蚀微小电流的测量，结果发现：选用现成设备测量试样的电偶腐蚀微小电流时，测量电流波动非常大，噪声明显超过实际信号输入——电偶腐蚀电流。经自行开发研制的MCD01电偶腐蚀计可以准确的测量腐蚀电流，特别是微小电偶腐蚀电流。     

可转位刀片三维断屑槽CAT/CAD/CAM系统

给出了一个可转位刀片三维断屑槽测量、设计与制造的CAT／CAD／CAM系统，并对该开发系统各部分结构和功能进行了简介。     

30CrMnSiNi2A钢件镀硬铬的氢脆分析

本文叙述了用延迟破坏法试验超高强度钢(υb=1700MPa)不超过三次镀硬铬的氢脆情况。     

65Mn钢圆锯片等温处理工艺的探讨

比较了６５Ｍｎ等温处理和淬火回火处理后的硬度、韧性、抗弯性能和耐磨性。６５Ｍｎ钢圆锯片用等温处理取代现行的淬火回火处理，将会在提高锯片的内在质量和节能方面取得明显效益。     

铝废渣废灰的治理

本文分析了铝的生产过程和加工应用过程产生的铝渣铝灰对环境的威胁;从化学组成分析了铝渣铝灰作为再生资源的可能性;提出了综合利用铝渣铝灰的几条可能途径.     

The characteristics of a low-power-consumption plasma jet and ceramic coatings

The effects of the composition of plasma gases (Ar-N₂, Ar-H₂), arc current, and voltage on the temperature and velocity of a low-power (5 kW) plasma torch in the arc field free region has been investigated using an enthalpy probe. Coatings of Al₂O₃-13TiO₂ were deposited under different conditions. The results show that in the Ar-N₂ plasma, the enthalpy, temperature, and velocity change little with arc current and voltage when regulating the nitrogen proportion in the plasma gas. The hardness of the resulting coatings is 800 to 900 kg/mm² HV.300. For Ar-H₂ plasma, however, increases in the H₂ content in the mixture of the gases remarkably enhanced the velocity and heat transfer ability of the plasma jet, with the result that the coatings showed high hardness up to 1200 HV.     

Growth of Au nanocrystals on CdS nanorods

Nanorods of S²⁻ rich CdS were synthesized by a reaction of excess S versus Cd precursors in the presence of ethylene diamine. The photoluminescence (PL) emission from the S²⁻ rich CdS nanorods was broad with a peak at ∼710 nm, which was 40 nm longer in wavelength than the PL peak from Cd²⁺ rich CdS (∼670 nm) nanorods. The influence of surface electron or hole trap states on the luminescent pathway of CdS nanorods will be discussed to explain these shifts in wavelength. Nanocrystals of Au ∼2 nm in size were grown on S²⁻ rich surfaces of CdS nanorods. Significant luminescence quenching was observed from the Au nanocrystals on the CdS nanorods due to interfacial charge separation. Change separation by the Au nanocrystals on the CdS resulted in enhanced photocatalytic degradation of Procion red mix-5B (PRB) dye in an aqueous solution under UV light irradiation.     

共沉淀法制备SiC/YAG复合陶瓷粉体

采用共沉淀工艺方法制备SiC/YAG陶瓷复合粉体,分析pH值和洗涤剂对共沉淀浆料及复合陶瓷粉体分散性的影响,对比添加剂(Al2O3+Y2O3)和复合陶瓷粉体SiC/(Al2O3+Y2O3)在加热过程中YAG相的形成过程.得出制备该复合陶瓷粉体的溶胶体系适宜pH值为10左右,采用无水乙醇水洗;复合陶瓷粉体在加热过程中YAG相的形成是一个由Y4l2O9→YAlO3→YAG过渡的过程.     

Investigation into the thermo-viscoplastic finite element analysis of square die extrusion of square section with Lagrangian description

An analysis of three-dimensional hot extrusion through landless square dies is carried out as a nonsteady-state problem. In the problem, difficulties arise from the severe distortion and die interference of elements at the aperture rim of the die, even with a small punch travel. Finite element simulation is impossible without intermittent remeshing procedures. To overcome these difficulties, an automatic remeshing technique is proposed by employing a modular conceptual mesh structure. In the analysis of temperature distribution, conduction, convection and radiation are considered in connection with a deformation analysis of a visco-plastic material. The effect of the mesh structure on the present scheme as well as material properties and temperatures associated with punch travel is discussed. As an example, an extrusion of a square section is simulated. In order to confirm the present scheme, experiments are carved out using aluminium at the elevated temperature.     

An investigation of phase transformation behavior in sputter-deposited PtMn thin films

Sputter-deposited, equiatomic PtMn thin films have application in giant magnetoresistive spin valves, tunneling magnetoresistive spin valves, and magnetic random access memory. However, the as-deposited films are found to be a disordered A1 phase in a paramagnetic state rather than an antiferromagnetic phase with L1₀ structure, which is needed for device operation. Therefore, a postannealing step is required to induce the phase transformation from the asdeposited A1 face-centered-cubic phase to the antiferromagnetic L1₀ phase. The A1 to L1₀ metastable transformation was studied by x-ray diffraction and differential-scanning calorimetry. An exothermic transformation enthalpy of −12.1 kJ/mol of atoms was determined. The transformation kinetics were simulated using the Johnson-Mehl-Avrami analysis.