组分和烧结温度对铁基结合剂冲击韧性的影响

本文利用正交试验法研究了铁基结合剂中添加组分Cu,Ni,Sn-Zn,WC不同含量在不同烧结温度下对胎体冲击韧性的影响程度。实验结果表明:各组元的不同含量和烧结温度都对胎体冲击韧性有很大的影响,相对来说,烧结温度的影响要小一些。在所有胎体冲击韧性的数据中,最大值为配方9在730℃烧结下的4.75J/cm2,最小值为配方5在700℃烧结下的1.86J/cm2,它们相差达155%。此外,方差分析得出,每种组元在不同的烧结温度下对冲击韧性的影响趋势不一样。     

烧结工艺对铁基结合剂金刚石节块力学性能的影响

本文研究了热压烧结中烧结温度和烧结压力对铁基结合剂金刚石节块力学性能的影响.实验结果表明:烧结温度对金刚石节块的硬度和抗弯强度等力学性能影响显著;而烧结压力对金刚石节块的抗弯强度和硬度的影响小于温度对二者的影响;节块的应力-应变曲线具有陶瓷的特性.     

WC的添加量对铁基结合剂性能的影响

本文在铁基结合剂中加入0％、2．5％、5％、7．5％、10％的WC粉,采用热压烧结法制备出不同WC含量的铁：基结合剂节块．并对铁基结合剂节块的硬度、抗弯强度和耐磨性进行了测试。实验数据表明：随着WC粉的含量从0％增加到10％,铁基结合剂的硬度逐渐增加;抗弯强度与耐磨性也同时提高。但抗弯强度与耐磨性的提高与WC加入量并非呈简单的线性关系。     

制备工艺对金属结合剂胎体抗弯强度的影响

本文以铁基和铜基结合剂为原材料,研究其在不同的球磨时间和烧结温度下抗弯强度的变化。实验结果表明:球磨时间和烧结温度对铁基和铜基结合剂胎体的抗弯强度有很大的影响。对于铁基和铜基结合剂,当球磨时间为30 h时、烧结温度分别为760℃和720℃时,样品的最大抗弯强度值分别为457 MPa和644 MPa。     

表面镀覆对铁基结合剂金刚石节块性能的影响

将表面不同镀覆(未镀、镀Ni和镀Ti)金刚石加入到铁基结合剂中进行热压烧结得到铁基结合剂金刚石节块,测试了节块的硬度和抗弯强度,用扫描电子显微镜对节块断口的微观形貌进行观测,用能谱仪对金刚石表面和金刚石脱落坑的成分进行了分析。结果表明,与表面未镀金刚石相比,加入镀Ni和镀Ti的金刚石,对节块的硬度影响不大,洛氏硬度(HRB)分别为109.4、112.4和112.3;但能使节块的抗弯强度有一定的提高,其值分别为641、658和695 MPa。SEM和EDS分析表明,镀覆金刚石表面镀层能使金刚石与铁基结合剂的结合更紧密,更牢固。     

烧结工艺对金刚石串珠Cu基胎体性能的影响研究

文章主要讨论了烧结温度、烧结压强对Cu基胎体硬度、抗弯强度、应力应变曲线及串珠剥离强度等力学性能的影响,实验结果表明:烧结温度、烧结压强对Cu基胎体力学性能影响显著,烧结温度越高,试样块的硬度值随之增高,达到最高值后变平稳,抗弯强度不断的增高,应力应变曲线由脆性断裂向韧性断裂发展;烧结压强越高,试样块的硬度值、抗弯强度值都呈现相应的增加;最后研究了烧结温度对串珠剥离强度的影响,结果表明在较低的烧结温度下,串珠胎体与基体结合强度明显不足,出现大量的串珠剥离现象,影响烧结串珠胎体的正常使用。     

CeO2对铁基结合剂镀Ni金刚石节块性能的影响

本文研究了金刚石表面镀Ni层的形貌和不同含量CeO2的加入对铁基结合剂镀Ni金刚石节块性能的影响。结果表明:稀土CeO2的加入对铁基结合剂镀Ni金刚石节块的抗弯强度有一定的影响;当CeO2加入量为0.8%时,能得到最优的性能。     

素化金属结合剂金刚石工具初探

金属结合剂金刚石工具广泛应用于各种硬脆材料的磨削加工.为改善磨具的力学性能和加工性能,常用的金属结合剂中加入大量的合金元素如Ni、Co、Cu、Zn、Sn、Pb、Cr等.一方面提高了材料成本,另一方面在制造和使用过程中可能会造成一定程度的重金属污染.因此,文章提出一种成分简单的"素化"金属结合剂,探索了烧结工艺对结合剂微...     

不同气氛下预烧结对串珠胎体物理性能的影响初探

使用铁基金刚石串珠胎体结合剂,冷压成试验块冷压坯,在不同气氛保护下采用同一工艺进行预烧结,预烧结完成后与未经预烧结的标准试验块一起,使用同一工艺将冷压坯烧结成型,通过设备检测其相对致密度,以及HRB、抗弯强度等物理特性。根据结果得出:在不同气氛预烧结后,该铁基金刚石串珠胎体结合剂配方的抗弯强度有非常大的差别,HRB硬度变化不大,而抗弯强度与HRB硬度和相对致密度并没有很强的关联,还原气氛下进行预烧结对其抗弯性能有正面影响,并且可以提高其韧性。     

金属结合剂金刚石工具胎体耐磨性随烧结温度变化的研究

文章重点研究了一种铁基金属结合剂金刚石工具胎体耐磨性随烧结温度升高的变化规律.通过对胎体耐磨性、硬度、抗弯强度、抗冲击强度等一系列物理性能指标的测定,以及利用该胎体制成的锯片做对比试切试验结果分析,得出以下结论:(1)铁基结合剂胎体耐磨性随温度的升高呈现3个阶段的规律变化;(2)测定出了耐磨性最佳时烧结温度范围.将该项研究成果应用于生产中可以大幅度地降低金属结合剂金刚石工具的单位产出能耗,符合国家节能减排的经济增长方式.     

乙烯酮(双乙烯酮)下游产品废水的治理技术

乙烯酮(双乙烯酮)是十分重要的化工中间体,其下游产品较多。江苏某化工厂开发生产乙烯酮(双乙烯酮)下游产品三十多个,年生产规模三万多吨,是国内以乙烯酮(双乙烯酮)为中间体生产精细化学品的综合骨干企业。针对乙烯酮(双乙烯酮)下游产品废水特点,该厂结合企业实际,开展了产品优化,结构调整,清洁生产,资源循环利用,节水降耗等工作,从源头削减了污染物的生产。同时投资二千多万元新建预处理装置三套,6000m3/d废水生化处理装置一套,使全厂乙烯酮(双乙烯酮)下游产品的废水得到了有效的治理。     

几种乙炔加压设备性能的比较

阐述并比较了几种加压设备在乙炔加压清净过程中的性能和特点。     

三种煤样燃烧热的测定

本文通过三个厂家提供的三种煤样燃烧热的测定,由测定结果综合得出3号煤样燃烧最完全、燃烧热也最大,是三个煤样中最好的一种。     

Semi-empirical equation of state of metals. Equation of state of aluminum

A semi-empirical equation of state for metals is described. Its capabilities are demonstrated by the example of the equation of state for aluminum. New experimental data are presented on the location of the isentrope of aluminum for unloading from the state at p = 229.71 GPa on the shock adiabat to an aerogel (SiO₂) of density 0.08 g/cm³. __________ Translated from Fizika Goreniya i Vzryva, Vol. 44, No. 2, pp. 61–75, March–April, 2008.     

水泥水化热测定方法综述

水泥水化热是中、低热水泥和核电工程用水泥的一项关键的技术指标。全球范围内测定水泥水化热的方法有溶解法、直接法/半绝热法、等温传导量热法三种。本文总结了中、美、欧相关方法标准,对其测试原理、仪器设备、试验过程等方面进行了比对,并对其在领域的应用做了简单的概括。     

小议汽车涂装工艺设计对涂装成本的影响

论述了涂装工艺设计对涂装设备投资、涂装生产成本的影响。     

Calorimetric and Computational Study of Enthalpy of Formation of Diperoxide of Cyclohexanone

A thermochemical rather simple experimental technique is applied to determine the enthalpy of formation of Diperoxide of ciclohexanone. The study is complemented with suitable theoretical calculations at the semiempirical and ab initio levels. A particular satisfactory agreement between both ways is found for the ab initio calculation at the 6–311G basis This set level. Some possible extensions of the present procedure are pointed out.     

Measurement of the gradient of viscosity with composition of mixtures of non-ideal gases

A perturbation viscometer is a differential capillary viscometer that measures the logarithmic viscosity gradient of the viscosity-composition curve for gas mixtures. Measurements are made at different gas mixture compositions. Integration of the logarithmic viscosity gradients measured over the full composition range gives the mixture viscosity relative to the viscosity of one of the pure components of the gas mixture. This method is attractive because, for measurements of equal precision, integration of the gradients is potentially an order of magnitude more precise than measurement of the viscosities directly. It can also work at high and low temperatures and perhaps high pressures.The perturbation viscometer has been used to make measurements on ideal gas mixtures at ambient and elevated temperatures. The situation is more complicated when the gas mixtures are non-ideal. Extra effects due to density differences, molar volume change on mixing and differential thermal expansion may be measured in addition to the desired viscosity change producing systematic errors in the results. Thus, a more sophisticated apparatus is required. The standard perturbation viscometer has been modified to separate out the extra effects to permit measurement of the true change in viscosity. In addition, the theoretical operation of the modified apparatus has been revised to account for the design changes to permit calculation of the viscosity-composition profiles from the results.The apparatus has been tested using helium-HFC-125 mixtures and two new viscosity-composition profiles are presented for these mixtures at 23 and . Internal consistency tests have been used to confirm that the data produced are of high quality with an estimated uncertainty in the viscosity ratio data at of 0.9% and at of 1.5%.     

塔设备改造选型的分析

就当前扩产增容中塔设备设计和改造时板式塔和填料塔的选型问题加以分析。在评述目前国内常用的几种塔板和新型填料之后，着重介绍一种新型塔板（导向梯形浮阀塔板）和一种新型填料（波环填料——乾隆帕克）。     

Effect of degree of deacetylation of chitin on the properties of chitin crystallites

In the present article, chitin from crab shell was systematically deacetylated using a NaOH treatment with control of the reaction time. The degree of deacetylation, monitored using solid-state NMR, revealed that the reaction was pseudo-first order. Based on this, swollen and NaOH-saturated particles are proposed as the reaction system. The weight loss of the partially saponified and neutralized samples after HCl hydrolysis increased linearly with the degree of deacetylation. The crystallinity of the samples was found to increase after acid hydrolysis. According to conductimetric titration, the surface charge density of the crystallites, after acid hydrolysis, was found to increase with base treatment time. The effect of surface charge on the formation of a chiral nematic phase, due to the rodlike nature of the crystallites, was explored. These results show that because the contribution of charged particles to the ionic strength was significant the double layer compression was affected, especially since the surface charge density was close to the Manning limit. © 1997 John Wiley & Sons, Inc. J Appl Polym Sci 65:373–380, 1997