微裂纹

By the analysis of stress, crack characteristics, cross section metallography, scanning electrometry microscopy, energy spectrum micro-area as well as material quality of top hair clip pipe of Primary reformer, finds out the reason for top hair clip pipe cracking is stress corrosion cracking, and puts forward defending measures.

通过对一段转化炉上发夹管受力分析、裂纹特征、断面金相、电镜扫描、微区能谱、材质等分析，找出了上发夹管开裂的原因是应力腐蚀断裂，提出防护措施。

The deformation mechanism is mainly the single-slip and cross-ship, the fracture mechanism is mainly the congregation of transgranular micro-hole, and large uniform deformation occurred before tough fracture, and therefore, the ability of plastic deformation and the mechanical properties of the material were remarkably improved. These fully indicate that the new melt-treatment developed in this work is an effective and advanced technique, and further testify that the improvement of metallurgical quality of the material is the key to enhance its mechanical properties, especially its plastic deformation performance. The results of tensile and compression tests at elevated temperature also indicate that the suitable hot-working temperature range is 400～450℃. 4. A steady-state plastic flow exists during the plastic deformation of the aluminum sheet used for pressure can at elevated temperature. A hyperbolic sine relationship can be satisfied between the steady-state flow stress and strain rate by introducing an Arrhenius term which involves some thermal activation parameters, i.

压力罐用铝材中的主要冶金缺陷为Al〓O〓夹杂物、气孔及富Fe杂质相；高效熔体处理显著改善了材料的冶金缺陷的存在形态，使含杂量明显减少、夹杂物尺寸变细小且分布均匀，富Fe杂质相变为细小、分布均匀的团球状或短棒状的复杂化合物，同时也明显细化了结晶组织；此外，由于高效熔体处理有效地减少了材料中裂纹萌生源数量，因而改变了材料的塑性变形微观过程及断裂方式，主要以单滑移和交滑移进行塑性变形，断裂方式为穿晶微孔聚集型，韧性断裂前产生了大量的均匀变形，不易出现变形失稳，从而显著提高了罐用铝材的塑变能力和力学性能。

The micro-indentation results show that both theories for finite and infinitesimal deformation agree well with experimental data by suitably chosen material lengths. The results for fracture show that the difference between finite and infinitesimal deformation only exists in the vicinity very close to crack tip.

结果显示通过改变材料常数大变形和小变形都可以和微压痕实验结果吻合好，大小变形理论在断裂问题上的区别仅仅存在于非常靠近裂纹尖端处。

During the transition from tangential fretting to composite fretting, and to radial fretting, the decreasing of component of tangential fretting was accompanied with the increasing of component of radial fretting.

对复合微动的动力学特性、耗散能变化、损伤形貌、第三体行为、白层的形成和演变规律、裂纹的萌生与扩展，以及磨损与疲劳的竞争关系进行了细致研究。

The results show that, by the way of optimizing preparation condition, the spherical zirconia powders with suitable particle size distribution are prepared using chemical precipitation method. Using heterogeneous chemical precipitation coating technique, the sph, erical nickel coated zirconia powders are prepared and the heterogeneous nucleation can be done on the surface of spherical zirconia powders. The thickness of coated layer, homogeneous degree and crack of surface can be controlled by the way of controlling powder concentration, adding rate of reactants feeding and adding surface active agent.

研究表明，采用化学沉淀法，通过优化制备工艺条件，可以制备粒径分布较均匀的球形氧化锆粉体；利用非均相化学沉淀包裹技术制备的金属镍包裹氧化锆微球粉体，球形氧化锆颗粒表面作为异相成核的场所，通过控制颗粒浓度、加料速度以及添加表面活性剂等工艺条件，可以调控包裹层厚度、表面均匀度以及表面裂纹等。

The equilibrium phase particles that induce the sensitivity of the quenching are not the direct reason that causes the alloy fracture; the microzone of PFZ around particles limits crack extension and coordinates deformation, this causes the formation of the ductile tension fracture.

引起淬火敏感性的平衡相粒子，不是造成合金断裂的直接原因，粒子周围的无析出微区起到了限制裂纹扩展和协调变形的作用，是合金形成延性拉伸断口的原因。

By core observation and slite analysis, two types of fractures can be identified in reservoirs including macro-fractures and micro-fractures. Macro-fractures refer to tectonic fractures and stylolites, and micro-fractures mainly refer to grain breakage fractures and micro-tectonic fractures.

通过岩心观察、薄片分析等方法研究让纳若尔油田储集层裂缝发育特征，发现油田发育宏观裂缝和微观裂缝两种不同尺度的裂缝，宏观裂缝包括构造裂缝和缝合线，微观裂缝主要是颗粒破裂纹和构造微缝。

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 vein of the crackle is crab claw and cobweb,making the smooth,transparent glaze appear as if it has a thousand small fissures.

钧瓷开片裂纹之声，如铃如泉，虚妙清冷；如琴如涧，有幽邃玄微；不啻天籁，静夜闻之，令人浑然忘我。

The cross-tie fibrils in craze microstructure, the relations between the molecular weight, entanglement density and the craze fracture behavior and the interaction between craze and crack growth are extensively reviewed.

考虑银纹细观结构中横系的作用，对银纹结构模型、银纹微纤断裂判据、微纤断裂行为的分子量和缠结密度相关性以及银纹与裂纹相互作用等问题进行了较详细的综述。

According to the clear water experiment, aeration performance of the new equipment is good with high total oxygen transfer coefficient and oxygen utilization ratio.

曝气设备的动力效率在叶轮转速为120rpm～150rpm时取得最大值，此时氧利用率和充氧能力也具有较高值。

The environmental stability of that world - including its crushing pressures and icy darkness - means that some of its most famous inhabitants have survived for eons as evolutionary throwbacks, their bodies undergoing little change.

稳定的海底环境─包括能把人压扁的压力和冰冷的黑暗─意谓海底某些最知名的栖居生物已以演化返祖的样态活了万世，形体几无变化。