裂纹

Based on the work flow of charging equipment, three worst work conditions of the clack box were defined. Then, based on thermal-structure coupled theory, the thermal-structure coupled of the clack box which suffered from mechanical and temperature load was analyzed using the powerful software ANSYS. The clack box's temperature field and stress field as well as the stress spectrum of danger area in actual working condition were obtained. Finally, based on crack initiation and crack extension theory, the clack box's fatigue life was predicted.

摘 要：根据装料设备的工作流程，确定阀箱3种最不利的载荷工况；基于热－结构耦合理论并利用有限元分析软件ANSYS研究阀箱在温度载荷和机械载荷作用下的热－结构耦合问题，得到实际工况下阀箱的温度场、应力场以及危险部位的应力谱；依据裂纹萌生和扩展理论对阀箱进行疲劳寿命预测。

For different materials,the macrostructure of damage sites are dissimilar.The microstructure of damage sites were indicated as follows:the damages of granite and marble after being particle impacted were made up of damage of cleavage surfaces and crystal faces and spread of cracks along phase interface and pore space,which is harmful to mechanical property;while the damages of concrete and mortar were made up of cracks of transition zone and aggregates and plastic flow of C-S-H,which may cause more hidden danger to perma nence than to mechanical properties.

对四种材料损伤形貌的微观分析表明：花岗岩、大理石受颗粒冲击后产生的损伤主要为拉应力导致的解理面、晶面的破坏以及裂纹沿相界面和孔隙的扩展，对其力学性能有较大的危害；混凝土和砂浆的损伤由过渡区开裂、骨料破裂和C-S-H的塑性滑移共同构成，对耐久性造成的隐患远大于对力学性能的影响。

The test of coffin model thermal-fatigue in notched plate specimen of the4Cr5MoSiV1 steel has been made, by self-made testing machine of the highfrequency heating and the draught quenching.

利用自制的高频感应加热、吹风冷却式试验机，对4Cr5MoSiVl钢缺口板状试样进行了Coffin型热疲劳试验。记录了热循环次数、热疲劳裂纹长度、试样中热应力变化之间的关系。

The causes for inner transversal cracks of cold-drawing heavy wall pipe of 42MnMo7 steel were analyzed.

针对42MnMo7钢冷拔厚壁管存在内表面横裂纹问题，分析了其产生的原因。

The texture of the cold-rolled sheet composite consists of three weak components, i.e.

冷轧板抗拉强度的降低是轧制时产生的大量做裂纹所致。

The microstructure of the as-sprayed zirconia coatings was analyzed. The results show that the nanostructured zirconia coating is a typical lamellar structure composed of columnar grain about 100nm in diameter.

结果表明：纳米结构涂层是由直径为100nm左右的柱状晶粒组成的层状结构；涂层中存在大量的微裂纹和分布均匀的细小圆气孔。

In this project, the selection criteria of matrix and reinforcement for obtaining composites with high strength and toughness are determined. The as-cast and aged microstructures of composites reinforced with particles of different strength are observed, and their metallurgical conditions and stabilization mechanisms are analyzed. The aging precipitation behaviors and mechanisms are studied. Some characteristics of nano-materials (micro-distortion areas) are found in 150nm- Al2O3p/Al composites and their formation mechanisms are expatiated. The "flexible" restriction to the deformation of the matrix by low strength AlN particle is observed by in-situ TEM and SEM techniques, and the mechanisms of its resist on cracks propagation and its contribution to composite strength are revealed. The high temperature deformation behaviors of Al2O3p/Al composites are studied. A rare-earth coating is established on sub-micron Al2O3 particles, leading to an improvement in wettability between coated Al2O3 and liquid aluminum and a decrease in infiltration pressure. The strength and ductility of coated particles reinforced composite are also increased. The interfacial characteristics, bonding structures and their formation mechanisms are studied, and the crystal orientation relationships between reinforcement particles and aluminum matrix are investigated. Finally a lighter composite with better balance of strength and damping properties is reinforced with hollow ceramic microballoons of ultra-lower strength.

本项目发现了获得高强度和高韧性复合材料的基体、增强体选择依据；观察了各种强度质点增强复合材料的铸态和时效态微观组织，分析其微观结构形成的金属学条件及稳定性机理，研究了其时效析出规律和时效机制，发现了150nmAl2O3颗粒增强铝基复合材料基体中的纳米材料特征，并解释了其形成机理；利用TEM和SEM动态拉伸技术发现了低强度质点AlN颗粒对变形协调的&柔性强化&机制，揭示了其对裂纹扩展的阻碍作用和对复合材料高强度的贡献；研究了中强度质点的Al2O3颗粒增强铝基复合材料的高温变形行为，并对其进行了稀土界面层设计与制备，改善了颗粒与铝合金之间的界面润湿性，降低了复合材料铸造渗透压力，提高了复合材料的强、韧性；研究了多种复合材料界面结构及形成机理，确定了增强体与基体之间的界面结合机制，分析了复合材料界面处的晶体学位向关系；最后制备了含微孔的中空型陶瓷颗粒增强的特种复合材料，得到了强度和阻尼综合性能较好的轻质复合材料。

The research in hot cracking reguarity of directionally solidified Rene125 alloys proved again the theory about solidification contraction and its compensation.

对涡轮叶片材料Rene 125合金定向凝固热裂规律性的研究再一次验证了热裂纹形成的凝固收缩补偿理论。

The hot cracking theory about solidification contraction and its compensation was thoroughly proved through experiments carried out for Al-Cu alloys in semi-eontinutive directional solidification vaecume device.

根据热裂纹形成的凝固收缩补偿理论，定义了反映合金热裂倾向的不可补缩温度区间、热裂倾向系数、凝固末期收缩速率和不可补缩长度等指标。

Spreading cover on a stone material surface, not only is to cover the stone material hair side, hollow, crack and scratch, enhances the stone material glossiness, but also to protect the stone material from the water or other bad factors, like SO2 and so on noxious gas has corrosive nature to the stone material, thus to avoids or postpone stone material surface oxidation, so to have the protection function.

在石材表面涂覆一层遮盖品，不单纯是为了掩盖石材毛面，凹陷、裂纹和划痕，提高石材的光泽度，还可保护石材免受水或其他不良因素，如SO2等有害气体对石材的侵蚀作用，避免或延缓石材表面氧化作用的发生和发展，从而起到保护的作用。

He knows that he's one of the mostdominant players in the NBA right now.

我知道他现在是联盟里最有统治力的球员之一了。

Using analysis method of BCG , the dissertation analyzed the management of voluntary service organizations .

利用BCG分析方法对我国的志愿服务组织管理进行了分析。