矿用高锰钢工件的爆炸硬化的研究

本文简单介绍了高锰钢所具有的冷加工特性,爆炸硬化技术的特点及其发展。较为详尽地阐述了塑性板状炸药的选用、煤炸硬化的工艺实施以及主要工艺参数的分析。     

低铝水泥耐火混凝土的硬化机理和性能

本文论述了耐火混凝土制备过程中，使用的某些复合结合体系硬化机理的特性，对使用或不使用添加剂的、水泥含量低的耐火混凝土的硬化机理和热处理性能进行了研究，概要地介绍了某些复合结合剂在生产水泥含量低的及超低的耐火混凝土中，与流化／扩散添加剂一起使用的潜在效果。     

高温地热井水泥水化硬化的研究

研究了由不同配比的高抗硫Ｇ级水泥与石英砂粉组成的高温地热井水泥在不同水热条件下的强度性能及其水化硬化过程，阐明了高温下硬化浆体水化产物的组成，形态，再结晶和水泥石显微结构及孔径分布是制约水泥石强度行为的有重要因素，为进一步改善和提高我国地热井水泥产品质量和耐热性能提供了理论依据。     

航天飞行器毁伤与防护的探索研究

针对航天飞行器的典型防护结构,介绍和总结了国内外开展超高速碰撞研究的历史和成果,提出急需开展研究的重点和方向,阐述了爆炸驱动加载、物理爆炸、自燃性金属材料等研究的主要内容和进展,同时说明这些研究在这个领域的重要性.     

低钙硅酸盐矿物碳化硬化性能研究进展EI北大核心CSCD

低钙硅酸盐矿物在一定湿度下能够与二氧化碳发生反应,反应产物能够迅速凝结、硬化形成致密的硬化体。为了更好地研究和利用低钙硅酸盐矿物的碳化硬化性能,综述了低钙硅酸盐矿物的碳化反应过程、碳化硬化机理等方面的研究进展。低钙硅酸盐矿物碳化形成的碳酸钙晶体和高度聚合的非晶态二氧化硅凝胶是硬化体强度增长的主要来源,并且低钙硅酸盐矿物组成、结构及其与胶凝性能的关系,碳化反应及硬化机理,碳化硬化体的结构和耐久性等方面需要进一步系统研究。     

电站锅炉金属材料的选择与使用

电站锅炉是受国家安全监察管理的具有爆炸危险性的特殊设备。锅炉金属材料的正确选择和使用,对确保电站锅炉的安全运行至关重要。错用钢材就相对增加了锅炉的潜在爆炸危险性。本文重点对电站锅炉金属材料的选择与使用进行分析探讨。     

呋喃树脂硬化反应的研究

采用红外光谱法等分析测试手段，研究了呋喃树脂硬化反应前后的结构变化，对目前铸造界比较倾向的呋喃环双键打开、直接加成的观点提出了疑问，并提出了呋喃破裂并进而聚合反应的新观点。     

树脂混练结修补料的高温流动性和硬化时间

本文叙述了在声转炉等冶炼用炉中，高温修补是提高炉子寿命的必要技术，报道研究了硬化快，发烟少树脂混炼的烧结修补料。     

非稳定结构矿物质的接触硬化性能

本文阐述了新奇的接触硬化工艺方法制备人造石的独特优点及其基本原理。作者们用动态水热合成方法制成了性能优异的以水化硅酸钙为主的接触硬化胶凝材料，研究了它们的强度与抗水性能，制成了立即抗压强度达８４Ｍｐａ的高强度接触经石材，以及金属与非机非金属接触经复合材料，讨论了接触经胶凝材料的发展前景。     

影响水泥—高钙灰硬化浆体膨胀性能因素分析

本文的研究是以实测获得的水泥－高钙灰体系浆体的各种性能数据为依据，经统计分析后，得拟合最优的表达水泥－高钙灰硬化浆体膨胀性能的指数关系。据此分析得出影响水泥－高钙灰硬化浆体膨胀性能的主要因素可归结为水泥的基础膨胀Ｐｕ值、高钙灰中游离氧化钙Ｆｆ值、高钙灰在混凝土中的参量以及表征膨胀敏感程度的Ｋ值，并初步探索改善水泥－高钙灰硬化浆体膨胀性能的途径和措施。     

Impact of impregnation with boron compounds on the surface hardness and abrasion resistance of some varnished woods

This study was performed to determine the impact of impregnation with boron compounds on the surface hardness and abrasion resistance of some varnished woods. For this purpose, test specimens prepared from Oriental beech, White oak, Scotch pine, and Uludag fir, which met the requirements of ASTM D 358, were impregnated according to ASTM D 1413‐99 with boric acid (Ba), borax (Bx), and boric acid + borax (Ba+Bx) by the vacuum technique. After impregnation, the surfaces are coated with synthetic (Sn), water‐borne (Wb) and acid hardening (Ah) varnishes in accordance with ASTM D 3023. the surface hardness of specimens after the varnishing process was determined in accordance with ASTM D 4366. The abrasion resistance of specimens after the varnishing process was determined in accordance with TS 4755. According to the wood type, impregnation material and varnish type, the surface hardness was the highest for Oriental beech impregnated with borax + boric acid and acid hardening varnish and the lowest for Uludag fir impregnated with borax + boric acid and synthetic varnish. According to the wood type, impregnation material and varnish type, the abrasion resistance was the highest for Oriental beech impregnated with borax + boric acid and acid hardening varnish and the lowest for Scotch pine impregnated with borax + boric acid and synthetic varnish. Those results should be taken into account for applications like parquet, flooring etc., where the surface hardness and abrasion resistance values are very important. © 2009 Wiley Periodicals, Inc. J Appl Polym Sci, 2009     

硬金镀层的研究进展

在电化学沉积金中添加微量的硬化剂钴或镍得到的硬化金通常具有较好的硬度、耐腐蚀性和耐磨性.硬化金被广泛应用为接触材料.介绍了对硬化金的电镀过程以及相应的镀层性质的研究.重点介绍了金的电化学还原机理、硬化剂的作用原理以及孔隙的形成和降低方法.最后介绍了新的电镀工艺和新合金以得到较小的孔隙率,从而可以减少金的用量,而不用牺牲...     

Nanoindentation of CVD diamond: comparison of an FE model with analytical and experimental data

This paper describes an experimental procedure for the determination of the hardness and the elastic modulus through nanoindentation of a CVD diamond coating using simple analytical formulae. Such tests, performed with a Berkovich indenter, were simulated by finite element analysis. Through the numerical analysis, it was possible to reproduce the load-penetration depth curves and thus, confirm the validity or correct the property calculations. Results show that the predicted property values can be affected by the assumed material strain hardening. By comparing the numerical values with the experimental results, it is possible to characterise, with sufficient accuracy, the material behaviour.     

Point Defect Hardening in MgO·3Al2O3

Vickers hardness in spinel increases by 23% after neutron irradiation to a fluence of 8.3 × 10²² n/m² at 100°C. Annealing at high temperatures above 100°C gradually decreases the hardness. Above 500°C, the hardness is reduced to almost the same value as that of unirradiated material. The hardness of spinel, irradiated at 470°C to a fluence of 2.4 × 10²⁴ n/m², is unchanged both after irradiation and after annealing up to 1000°C. The length change during annealing was also measured and is similar to the hardness change. Frank dislocation loops with a density of 3 × 10¹⁴/cm³ are induced by neutron irradiation at 470°C but they apparently do not affect the hardening in spinel. Thus, point defects are concluded to act as obstacles against dislocation movement. The yield stress measured at 1400°C is also unchanged after irradiation. It is believed that not only the point defects but also the loops are annihilated by annealing at 1400°C.     

Indentation of an oriented transparent polyamide

In this study, the effect of orientation on the indentation hardness and energy absorption of an oriented transparent Trogamid polyamide was investigated with a spherical indentation methodology. It was found that the orientation significantly improved the indentation hardness and energy absorbed by plastic deformation. From the indentation hardness measurement, the elastic modulus, yield stress, and strain hardening exponent were derived from both the elastic and plastic regions of the indentation load–displacement curves. The elastic modulus was found to remain the same with orientation; the yield stress and the strain hardening exponent increased with orientation. The increase in the strain hardening exponent was the primary reason for the improved indentation hardness and energy absorption in the oriented samples. The mechanical properties from indentation measurements were compared to values obtained from tension true stress/true strain measurements. Good agreement was observed between the results from the indentation and tension tests. The effect of temperature on the mechanical properties was also studied. It was found that the modulus and yield stress were higher at a lower temperature; however, the strain hardening exponent remained unaffected. © 2008 Wiley Periodicals, Inc. J Appl Polym Sci, 2009     

12Cr1MoV管道爆炸事故技术分析

通过宏观检查、化学成分分析、硬度测量、金相检查和焊接、热处理工艺分析,对一起管道爆炸事故的原因进行了分析,得出事故管道爆炸为典型的热处理工艺不当所致,焊缝中出现了高硬度板条状马氏体,导致调试过程中脆性开裂,发生爆炸.     

Predictive model for spherical indentation on elastoplastic nanocomposites: Loading and unloading behavior

The response of elastoplastic nanocomposites in contact with rigid indenter has a lot of importance in engineering applications such as material characterization, Young modulus, Poisson's ratio and strain hardening parameters. With the aim of presenting a predictive model for the loading and unloading response, the problem of contact between elastoplastic composites with stiff spherical indenter was simulated using 2D axisymmetric model implemented in ANSYS. Parametric studies were performed numerically to investigate effects of geometrical and material parameters on the behavior of nanocomposites. Based on the parametric study observation, a normalization procedure is presented to express the loading and unloading responses in a nondimensional form. Three equations were numerically derived by fitting the FE normalized data to predict the loading and unloading responses and the residual indentation depth after unloading for elastoplastic nanocomposite with wide range strain hardening exponent. The predictions of proposed equations were in excellent agreement with experimental results for Al-Al₂O₃ nanocomposites and also with other experiments available in the literature for nanocomposites and pure metals. Moreover, derived equations were exploited to predict the Rockwell hardness of nanocomposites.     

蒸汽冷凝水回用过滤技术探讨

在对蒸汽锅炉冷凝水回用状况的市场调查和新型过滤器研制的基础上,提出了一种新的工艺组合--高温烧结陶瓷过滤和脉冲式气水复合反冲洗工艺,用于去除蒸汽冷凝水中的铁,以提高冷凝水的品质,并使之达到回用标准.通过采用该工艺,解决了普通过滤器处理蒸汽冷凝水中存在的反洗用水量大、滤料板结和滤料产生溶出物等问题.     

脉冲电流密度对电沉积纳米晶镍织构和硬度的影响

采用脉冲电沉积法制备了韧性较好的纳米晶镍镀层。考察了脉冲峰值电流密度对纳米晶镍镀层织构和硬度的影响。结果表明,随着脉冲峰值电流密度的增加,Ni(111)晶面择优取向程度逐渐增强,晶粒显著减小,镀层的硬度逐渐增加。纳米晶镍镀层硬度与晶粒尺寸的关系符合经典的Hall—Petch效应。     

Impact of impregnation with boron compounds on the surface hardness of varnished wood

This study was performed to determine the impact of impregnation with boron compounds on the surface hardness of varnished wood materials. For this purpose, test specimens prepared from Oriental beech (Fagus orientalis Lipsky) and oak (Quercus petreae Lipsky), which met the requirements of ASTM D 358, were impregnated according to ASTM D 1413 with boric acid and borax by a vacuum technique. After impregnation, the surfaces were coated by cellulosic, synthetic, polyurethane, waterborne, acrylic, and acid hardening varnishes in accordance with ASTM D 3023. The surface hardness of the specimens after the varnishing process was determined in accordance with ASTM D 4366. According to the wood type, impregnation material, and varnish type, the surface hardness was highest for the oak impregnated with borax and acrylic varnish and lowest for the oak impregnated with borax and synthetic varnish. Therefore, impregnation with boron compounds showed an increasing impact on the surface hardness of the varnished wood. © 2007 Wiley Periodicals, Inc. J Appl Polym Sci 2007