面向对象的液压与气压回路工作原理仿真软件开发

详细介绍了用于液压与气压传动课程教学的“面向对象的液压与气压回路工作原理仿真软件”的开发，该软件采用VB6．0、AutoCAD及Microsoft Visio在Win2000操作系统上开发而成，采用了面向对象的建模技术，实现了液压与气压原理图的自动识别及工作原理仿真。     

扫描电镜在质量事故分析中的应用

应用扫描电镜断口分析、能谱定性分析、光学显微形貌测试等方法 ,针对公司重要产品因细小裂纹而连续四炉产品全部报废的重大质量事故 ,分析了引起报废裂纹缺陷的性质及产生原因。结果表明 :缺陷主要是大量集聚分布的脆性Al2 O3 夹杂及其裂纹 ,属原材料缺陷 ,是冶炼时氧化还原工艺控制不当 ,或加Al量不均匀所致。据此立即采用了相应调整和改进冶炼工艺措施 ,有效消除了原始缺陷 ,迅速提高了产品质量和效益。     

Influence of heat treatment on fracture and magnetic properties of radially oriented Sm2Co17 permanent magnets

The quenching, fracture and aging treatment of radially oriented Sm2Co17 ring magnets were investigated. The results indicate that the ring magnets have obvious anisotropy of thermal expansion, which easily leads to the splits of the magnets during quenching. The fracture is brittle cleavage fracture. The difference （Aa） of the expansion coefficient reaches the maximum value at 800-850 ℃. So, various quenching processes at different steps are adopted in order to reduce the splits. When the magnets are aged, 1：5 phase precipitates from the 2：17 matrix phase and forms a cellular microstructure with 2：17 phase. BHmax and JHc reach the maximum value 226 kJ/m^3 and 2 170 kA/m after being aged at 850 ℃ for 4 h and 8 h, respectively. The aging treatment at 850 ℃ has little influence on remanence（Br）, which can always keep a high value （≥1.0 T）. Through appropriate heat treatment, the ring magnets have uniform cellular microstructure and excellent magnetic properties： Br ≥ 1.0T, JHc ≥2 100 kA/m, BHmax ≥ 220 kJ/m^3.     

新型镍基粉末高温合金动态再结晶的数学模型

采用Gleeble 15 0 0热模拟试验机对新型镍基粉末高温合金在 10 70℃～ 1170℃ ,应变速率为 5× 10 - 4s- 1～2× 10 - 1s- 1的条件下进行了轴向压缩试验。通过加工硬化率和应变的关系曲线确定稳态应变εs,并绘制了该合金的动态再结晶图。结果表明 ,Zener Hollomon参数变化对动态再结晶的临界应变量影响较小 ,对稳态应变量影响较大 ,并建立了该合金的动态再结晶动力学模型和晶粒尺寸模型     

用攀枝花钛矿和云南钛矿冶炼钛渣工业试验研究

通过磁性测量和X-射线衍射研究了Gd2(Co，Al)17化合物的结构和磁晶各向异性。当x≤4时，样品具有菱方Th2znl7型结构，x=5时，具有六方CaCu5型结构。随着Al浓度增加，晶格常数和单胞体积单调增大，而居里温度和自发磁化强度近似线性地减小；在x≥l时，观察到Co亚点阵的磁晶各向异性变号，室温易磁化方向由易面转变为易轴，且易轴各向异性场和各向异性常数随Al原子浓度增加出现极大值；基于补偿温度(65K)下自由粉末颗粒的磁化曲线，导出了亚点阵间的分子场系数和Gd-co交换耦合常数，结果表明，Al原子对Gd-Co交换耦合作用的影响较小。根据Al原子在Co亚点阵4种晶位的择优占位，分析了磁晶各向异性的演变。     

Effects of CeO2 doping on the structure and properties of PSN-PZN-PMS-PZT piezoelectric ceramics

Quinary system piezoelectric ceramics PSN-PZN-PMS-PZT were prepared by using a two-step method. The effects of CeO2 doping on piezoelectric and dielectric properties of the system were investigated at morphotropic phase boundary （MPB）. The results reveal that the relative dielectric constant ε33^T｜ε0, the Curie temperature To, the piezoelectric constant d33, the mechanical quality factor Qm, and the electromechanical coupling coefficient Kp are changed with the increase of CeO2 content. On the other hand, the effects of CeO2 doping on the dielectric properties of PSN-PZN-PMS-PZT piezoelectric ceramics at high electric field are consistent with the change at weak electric field. The values of dielectric constant and dielectric loss are enhanced with the increasing of electric field.     

Synthesis of Ti3SiC2 by spark plasma sintering(SPS)of elemental powders

Ti3SiC2 materials have been fabricated by spark plasma sintering of the elemental powders with the addition of Al.At the heating rate of 80℃/min and under the pressure of 30MPa,the ideal synthesis temperature of Ti3SiC2 is in the range of 1150-1250℃.The addition of Al is in favor of the formation of Ti3SiC2.The synthesized compound has the molecular of Ti3Si0.8Al0.2C2 and lattice parameters of α=0.3069nm,c=1.7670nm.Its grain is plane-shape with a size of about 50μm in the elongated dimension.The prepared material has Vickers hardness of 3.5-5.5GPa(at 1N and 15s) and is as readily machinable as graphite‘s.     

K2O和Na2O对高Al2O3炉渣组元活度和MgO含量的影响

 随着高品位铁矿石消耗的加快,资源逐渐趋于贫化,钢铁企业可利用的铁矿石原料逐渐向中低品位原料转变,尤其是高铝铁矿,这类原料的使用无疑会增加高炉渣中Al₂O₃质量分数,影响高炉现有的操作制度。Al₂O₃质量分数为15%～17%的高炉渣,由于Al₂O₃含量高而使高炉渣的冶金性能变差,为了保证高炉渣的冶金性能,必须在其中添加8%左右的MgO。然而,Al₂O₃含量相似的浦项钢铁的高炉渣,其MgO质量分数仅为4%左右,高炉实现了高效、稳定、顺行。因此,从高炉CaO-SiO₂-Al₂O₃-MgO四元渣系的物理化学机理出发,研究了K₂O、Na₂O对高炉渣四元渣系CaO-SiO₂-Al₂O₃-MgO中各组元活度的影响;研究了“渣-气”平衡条件下渣中碱金属氧化物和气体中碱金属的关系;计算了K₂O、Na₂O和MgO对黏度的影响。结果显示,在考虑高炉渣CaO-SiO₂-Al₂O₃-MgO中各组元活度、碱金属在渣-气间的分布和炉渣黏度的情况下,当碱金属氧化物K₂O和Na₂O存在时,可以适当减小MgO含量,并可以保证高炉渣各组元活度及炉渣黏度基本不变。这不仅有助于减少高炉原料中添加含镁熔剂、提高原料品位、高效排碱、降低碱危害、减少碳排放、延长高炉寿命及降低成本,还能促进钢铁企业实现节能减排的目标。     

Pd^2＋离子对TiO2光催化薄膜化学稳定性的影响

采用Sol—Gel工艺在普通玻璃表面制备出均匀、透明的添加0．3％～0．5％贵金属Pd^2 的TiO2-SiO2复合薄膜。通过对薄膜的XRD，SEM表征及薄膜耐酸、碱化学稳定性的检测，结果表明，在TiO2—SiO2薄膜中添加Pd^2 ，增强了TiO2薄膜的光催化活性，由于Pd^2 所起到阻滞剂的作用，使晶粒尺寸减小，表面呈多孔合理结构，改善了TiO2薄膜的显微结构，使薄膜的化学稳定性得到明显的提高。     

离心成型法制备Al2O3/Ni功能梯度材料及性能表征

用离心成型法制备了Al2O3/Ni功能梯度材料,并研究了料浆调制工艺、制备参数和梯度材料的力学性能.结果表明,良好的料浆的最佳流动性配比为粘结剂(聚乙二醇)含量为2 mass%、固相含量为63 vol.%、球磨时间为36 h.经离心成型-真空烧结(1400℃,2 h)可获得致密、组元宏观连续过渡的Al2O3/Ni梯度材料.该复合材料孔隙率低,力学性能好,抗弯强度可达321 MPa.