轮胎用帘子布硬度浅析

汽车工业的快速发展,对轮胎的使用性能提出了更高的要求,特别是它的安全性、耐磨性等,因此国内外各大轮胎公司对轮胎帘子布的性能指标要求越来越严格,包括帘子布的捻度、强力、粘合力及硬度等指标。现仅对帘子布的硬度指标作一剖析。因为若帘子布的硬度太大,在轮胎的加工制造过     

二氧化碳除硬度工艺实践

为解决废水回用过程中因废水处理工艺产生的废水硬度较高，容易造成设备和管道结垢等问题，采用“氢氧化钠+二氧化碳”法除硬度工艺降低废水硬度。实践应用表明，该技术能有效地降低废水处理成本，减少二氧化碳排放量，实现废水循环回收利用，符合国家环保政策要求。“氢氧化钠+二氧化碳”法除硬度工艺操作简单，控制精细，自动化程度高，系统运行稳定，运行成本低，处理效果好，能够有效利用含CO₂的废气，且无结垢风险，处理后的水完全满足回用要求。     

镀层硬度的测定

硬度是材料的一种机械性能.在表面处理行业中,硬度是检验镀层或其它涂层质量的重要指标之一.介绍了硬度的定义、测定方法、特点及表示方法等.其中测试方法按施加试验力的方式分类介绍,在八种测试方法中侧重适用于镀层及涂层表面维氏硬度、努氏硬度和洛氏硬度的测定.     

低硬度的印刷胶辊的研制

胶辊是印刷机的重要部件,低硬度的印刷胶辊常用于传递油墨,通过胶辊将油墨传至印刷版上去,并且要求它能够抗耐亚麻仁油、煤油或机油等。尤其是凸版印刷用的胶辊要求硬度低,以便印刷的成品清晰。     

水性木器涂料的硬度问题

讨论了硬度的定义、水性木器涂料漆膜硬度的影响因素、硬度与抗划伤性和耐磨性的关系、水性木器涂料硬度的常用测量方法。强调了测量方法本身侧重点的不同造成测试结果的不可比性。对水性木器涂料硬度的要求应该根据涂料的实际用途而定，不必过分追求高硬度。     

水性木器涂料的硬度问题

讨论了硬度的定义、水性木器涂料涂膜硬度的影响因素、硬度与抗划伤性和耐磨性的关系、水性木器涂料硬度的常用测量方法。强调了测量方法本身侧重点的不同造成测试结果的不可比性。对水性木器涂料硬度的要求应该根据涂料的实际用途而定,不必过分追求高硬度。     

探究生活饮用水测定总硬度的影响条件

生活饮用水是否达标直接影响人体健康,《生活饮用水卫生标准》中明确规定了各项指标卫生要求,其中要求总硬度(以CaCO_3计,mg/L)限值为450 mg/L,但测量生活饮用水的总硬度时往往存在诸多影响因素,导致测量结果存在误差。因此,本文通过研究水样的pH值、水样温度、缓冲溶液加入量、反应时间的快慢、滴定速度、干扰物质等因素对测定水中总硬度结果准确度的影响,探究出生活饮用水测定总硬度的最佳条件为:p H=7左右的中性水溶液,测定温度为25～30℃,缓冲溶液的加入量为2.00 mL,加入缓冲溶液后1 min内进行测定。通过该条件对生活饮用水的总硬度进行测定,极大地提高了水中总硬度测定的准确性。     

陶瓷砖莫氏硬度检测方法探讨

详述评价陶瓷砖表面质量好坏的重要指标硬度—莫氏硬度检测方法,根据不同人员、对不同陶瓷砖的检测数据,分析检测结果差异原因、影响检测结果因素分析,最后提出对该项目检测方法标准化、规范化的建议。     

涂膜硬度试验的技术进展

涂料应用中，往往针对不同的目的与环境，对涂膜硬度提出不同的要求，而采用各种试验方法及配套仪器测定涂膜硬度，则是合理改良涂料配方，控制涂膜硬度，保证涂装质量的有效手段之一。专家刘振作先生在本文中阐述了涂膜硬度试验的物理概念及重要意义，介绍了目前国内外普遍采用的多项试验方法与测试仪器的技术特征，同时指出了涂膜硬度试验今后的技术发展趋势。     

涂膜硬度及其测定方法

简要介绍了国家相关标准中铅笔硬度、摆杆硬度、压痕试验、划痕试验规定的漆膜硬度测定方法及其注意事项。     

水质硬度测定用复合硬度指示剂的研究应用

研究配制了复合硬度指示剂。试验证明，用此指示剂及比色卡可简单迅速测定在0－0.05mmol/L范围内水样的硬度。经使用效果良好，有推广使用的可能。     

Measurement of hardness and friction properties of pencil leads for quantification of pencil hardness test

We have investigated the various properties of different types of pencil leads in order to quantify a pencil hardness test for reliability. The chemical composition and mechanical properties for different types of pencils (F, 2H, 4H, 6H and 8H) were measured using X-ray diffraction, nano-indentation and a tribometer. The values for nano-indentation hardness of the pencil leads are in the range of 0.3–0.8?GPa. A higher hardness grade in the pencil lead leads to a wider error range. The clay content of the lead seems to be proportional to the hardness of the pencil lead. Different crystalline phases in clays for each grade of pencil lead result in variations in the degree and distribution of the hardness. Consequently, the content of the crystalline phases in the clay affects deviations in the hardness.     

Comment on hardness definitions

The different definitions of hardness and elastic modulus as obtained using indentation with conical (also Vickers and Berkovich) or spherical indenters are compared and relationships that permit a conversion and an assessment of the differences are derived. A comparison to experimental data is given.     

Measurement of hardness on traditional ceramics

To reveal quantitatively the hardness of clayware and stoneware, Mohs, Vickers (micro and macro) and superficial Rockwell indentation measurements were applied to roofing tiles with different porosity. This work discusses the comparison of different indentation results, indentation size effect on porous clayware and the effect of microstructure on hardness of tiles. As a result, for Vickers indentation test, the critical indent load was found to 0.5 and 1 kg for soft and hard tiles, respectively, and indentation size/load effect (ISE) appeared clearly in hard tiles. The relationship between load (P) and indent size (d) on tiles was very close to a modified Myer’s law. The PSR (proportional specimen resistance) model gave P/d=0.67+0.02d, P/d=1.33+0.1d for soft and hard tiles, respectively. It was found that there were no difference in hardness of tiles mounted with epoxy or copper and as-received sample under superficial Rockwell indentation. These concepts on the harness evaluation of tiles would be applicable to other clayware.     

低硬度网球胶料的研制

通过研究硫化体系、补强体系和软化剂对以NR为主体材料的网球胶料性能的影响,实现低硬度优质网球胶料配方的优化设计。优化配方为NR 100,碳酸镁15,氧化锌5,硬脂酸1.5,芳烃油5,硫黄2.5,促进剂DM/D 0.75/0.3;采用优化配方制得的网球胶料性能良好,达到了设计要求。     

Consolidation behavior and hardness of P/M molybdenum

In this study, the consolidation behavior and hardness of commercially available molybdenum powder were investigated. In order to analyze the compaction response of the powder theoretically, an elastoplastic constitutive equation based on the yield function presented by Shima and Oyane was applied to predict the compact density under uniaxial pressure from 100 MPa to 700 MPa. The compacts were sintered at 1400-1600 °C for 20-60 min. The sintered density and grain size of molybdenum were increased with increasing the compacting pressure and processing temperature and time. The effect of the porosity and grain size on the hardness of the specimens was explained based on the modified plasticity theory of porous material and the Hall-Petch type equation.     

Scratch hardness and deformation maps for polycarbonate and polyethylene

This paper presents results obtained from the scratching of an ultrahigh molecular weight polyethylene (UHMWPE) and a polycarbonate (PC). The data are used to obtain various surface mechanical properties such as the hardness and also the prevailing deformation mechanisms. Scratch results are reported for the case of rigid conical indenters for various tip included angles, bulk temperatures, scratch velocities, and applied normal loads. Scanning electron microscopy (SEM) and laser profilometry data are used to study the surface deformation and damage mechanisms, and to assess the topography of the surfaces after scratching. Deformation maps are provided for these polymers under different experimental conditions, which describe the various deformation characteristics. In general, these polymers show both increasing and decreasing trends for the scratch hardness values with variation of cone angle, (4qW/ηd²; where W is the normal load, d the width of the residual scratch, and q is a characteristic contact parameter, which ranges between 1 and 2). The scratch velocity, which governs the imposed strain rate, imparts an increasing effect on the hardness values, whereas a higher bulk temperature of the material decreases the scratch hardness. The measured responses of the surface properties of these polymers are shown to greatly depend upon the kind of deformation mechanism prevalent during the scratching and associated material removal processes.