皮革崩裂试验仪试验力的校准方法

正皮革崩裂试验仪的试验力(以下简称"皮革崩裂试验力")是该试验仪器的主要计量性能之一,由于目前没有专门校准皮革崩裂试验仪的相关计量技术规范,以及皮革崩裂试验仪结构条件限制了皮革崩裂试验力校准的可操作性,客观上造成一些使用单位和校准机构对该试验仪器是否需要校准或如何校准存在一定困惑。本文基于对皮革崩裂试验力校准技术的研究,介绍一种皮革崩裂试验力校准装置和校准方法,并通过分析评定其测量不确定度说明校准方法的适用性。由于皮革崩裂试验仪自身既不具备安装标准测     

不留痕试验仪校准方法

介绍了不留痕试验仪的组成及试验原理。根据GB/T 24129-2009,确立了不留痕试验仪校准的四项主要参数,并提出了各参数的校准方法。同时,对不留痕试验仪的试验总荷重、试验台往复运动频率这两项关键校准参数实测值的测量不确定度进行了评定。旨在解决我国目前尚无不留痕试验仪相关计量技术规范的情况下,不留痕试验仪的量值溯源问题,为各类计量技术机构开展不留痕试验仪的校准提供技术参考。     

变压器差动保护试验的优化算法

本文以P632型变压器差动继电器为例,分析其工作原理及计算公式,创新性地使用三相试验仪代替原有的六相试验仪进行试验,并利用EXCEL的函数计算功能,实现通过输入变压器数据和整定值,得到试验标准数据,完成差动保护计算。     

热稳定性试验仪校准方法的研究

热稳定性试验仪是当今检验部门以及化工产品生产企业广泛使用的试验仪器之一,并且在质检和生产中使用频率较高。为了确保热稳定性试验仪的量值准确可靠,本文详细介绍了热稳定性试验仪主要参数的校准方法,为热稳定性试验仪的校准工作提供了思路和可行方法。     

针焰试验仪校准方法的研究

针焰试验仪是当今质量检验部门以及化工产品生产企业广泛使用的试验仪器之一。为了确保针焰试验仪的量值准确可靠,为该仪器提供校准的依据,对针焰试验的校准方法进行了研究,并完成了《针焰试验仪》广西地方校准规范的起草准备工作。     

热收缩试验仪校准方法的研究

热收缩试验仪是当今检验部门以及化工产品生产企业广泛使用的试验仪器之一。它广泛应用于化工、药品、电子仪表等行业。为了确保热收缩试验仪的量值准确可靠,为该仪器提供校准的依据,对热收缩试验仪的校准方法进行了研究,并完成了《热收缩试验仪》广西地方校准规范的起草准备工作。     

砂当量试验仪校准结果不确定度评定

由安庆市计量测试所首次制定的《砂当量试验仪校准规范》已顺利通过安徽省质量技术监督局验收。该校准规范选用的计量标准器及校准方法科学、合理,具有很强的操作性。在校准规范编制过程中,参考了JJF1059. 1-2012《测量不确定度评定与表示》、JTGE42-2005《公路工程集料试验规程》、JTGB01-2014《公路工程技术标准》,对砂当量试验仪试筒刻度线、配重活塞质量、配重活塞底座直径、振荡器振荡频次、振荡器振荡时间校准结果进行评定,通过多次校准试验,验证其评定方法科学、合理,对砂当量试验仪校准有很强的指导意义。     

热延伸试验仪校准方法的研究

热延伸试验仪是当今检验部门以及化工产品生产企业广泛使用的试验仪器之一。它广泛应用于机械、国防工业、轻工电子、仪表等行业。为了确保热延伸试验仪的量值准确可靠,为该仪器提供校准的依据,对热延伸试验仪的校准方法进行了研究,并完成了《热延伸试验仪》广西地方校准规范的起草准备工作。     

单根绝缘电线电缆火焰垂直蔓延试验仪校准方法的研究

单根绝缘电线电缆火焰垂直蔓延试验仪是当今检验部门以及化工产品生产企业广泛使用的试验仪器之一。为了确保单根绝缘电线电缆火焰垂直蔓延试验仪的量值准确可靠,为该仪器提供校准的依据,对单根绝缘电线电缆火焰垂直蔓延试验仪的校准方法进行了研究。     

水平垂直燃烧试验仪校准方法的研究

水平垂直燃烧试验仪是当今质量检验部门以及化工产品生产企业广泛使用的试验仪器之一。为了确保水平垂直燃烧试验仪的量值准确可靠,为该仪器提供校准的依据,对水平垂直燃烧试验仪的校准方法进行研究,并完成了相应的《水平垂直燃烧试验仪》广西地方校准规范的起草准备工作。     

Field investigations of abrasion resistance

An extensive field investigation has been undertaken to assess the abrasion resistance of concrete floors in industrial premises. The performance was expressed in terms of the depth of wear produced by an accelerated abrasion machine, which simulated the damage mechanisms in a typical warehouse or factory. The results were used to compare site and laboratory practices, and this demonstrated that results obtained solely with laboratory methods may not be applicable to industrial concrete floor slabs. A comparison between the results obtained from the accelerated abrasion test and subjective assessments of service wear, showed a general agreement, and indicated that the apparatus provides a means for assessing the quality of concrete floor slabs in terms of abrasion resistance.     

铝合金表面耐磨复合膜的制备及其性能

针对在特殊场合对铝合金耐磨性、耐腐蚀性的高要求,结合铝合金阳极氧化工艺以及阳极氧化膜多孔的特点,在阳极氧化电解液中添加耐磨性物质n-SiC,使之进入到多孔铝合金阳极氧化膜中,达到提高耐磨性和耐腐蚀性的要求;运用正交试验法得到了添加n-SiC复合阳极氧化最佳工艺方案为:温度20℃,n-SiC添加量20mg/L,电流密度2A/dm2,氧化总时间40min。扫描电镜和X射线能谱分析结果证实n-SiC进入了氧化膜中;通过磨损试验机、盐雾腐蚀试验箱对复合阳极氧化膜的性能进行了检测,表明添加n-SiC可以提高复合阳极氧化膜的耐磨性。     

Development of an accelerated abrasion test apparatus with a standardized testing procedure

Depending on the nature of the working environment, the abrasive wear of concrete floor slabs can range from scratching or scuffing to impact and local crushing. To assess abrasion resistance it is, therefore, necessary to have a versatile apparatus. This investigation describes the development of a basic apparatus with three modes of action and a standardized testing procedure, for assessing the abrasion resistance of concrete slabs in the industrial environment. It consisted of a rotating plate carrying a total load of 65 kg so that it was sufficiently portable for both laboratory and site testing. Three different types of abrasion head—(a) revolving pads, (b) rolling wheels, (c) dressing wheels—could be fixed to the plate so that the effects of different modes of wear could be assessed. The abrasion resistance is expressed in terms of the depth of the groove produced by 15 min of abrasion. A laboratory programme was undertaken to assess the apparatus and test method. The factors examined included the methods of assessing the abrasive wear, the duration of the test, the minimum number of tests to reliably assess the abrasion resistance, the relative performance of the three types of test head and the mechanism(s) by which each head abraded the concrete surface. Consequently a standardized procedure was developed which was found to be sensitive to variations in surface conditions. This has the additional advantages of simulating service conditions and of being repeatable, easy to follow and with the cost and time of testing not being excessive.     

Experimental investigation of hardfaced martensitic steel under slurry abrasion conditions

Wear by slurry abrasion is a potential problem in engineering components subjected to particulate flow. The life of the components under slurry abrasive wear situations is primarily decided by operating conditions and the materials properties. Martensitic steels are widely used for abrasion resistant applications. The present work reports slurry abrasion response of hardfacing martensitic steel under a wide range of experimental conditions. The response data is generated using systematic and simultaneous variation of test parameters. The experiments were performed using silica sand slurry with different slurry concentration, particle size, sliding distance and load. The results of the investigation suggest that slurry concentration had relatively stronger effect than normal load. The wear volume loss exhibited an increasing trend with increasing severity of test parameters. An empirical equation is proposed to describe the interactive effect of the test parameters, abrasive particle properties and material property. SEM (Scanning Electron Microscope) studies revealed different morphology of the worn surfaces which was attributed to mild to severe slurry abrasion test conditions.     

Flexural fatigue and surface abrasion of Kevlar-29 and other high-modulus fibres

This investigation deals with some flexural fatigue and abrasion studies of Kevlar-29, glass and carbon fibres. The test methods included in the study are fatigue by pure flexing, buckling and rotation over a wire, and abrasion by rubbing against a rotating rod. Kevlar-29 fibres were found to perform well in these tests because they could survive the relatively high bending strains by yielding in axial compression. Carbon and glass fibres, although unable to survive at these high strains, did perform well when very low bending strains and tensions were used. Kevlar-29 fibres were found to be less abrasion-resistant than glass fibres, probably because of their low radial strength. The fracture morphologies of Kevlar-29 fibres in nearly all these tests showed axial splitting, confirming indications of low strength in the fibre perpendicular to its axis.     

喷磨试验仪法测定阳极氧化膜的平均耐磨性标准解析

喷磨试验仪法是阳极氧化膜耐磨性的测定方法之一,它可以测量阳极氧化膜的平均耐磨性,并进行分层检验。通过对比国内外和新旧版喷磨标准,讨论了GB/T 12967.1—2008标准修订过程中改进完善的几个方面。通过对取样和磨料等方面的修订,使新版标准具有更强的普遍适用性。     

Effect of rock properties on the Los Angeles abrasion and impact test characteristics of the aggregates

Aggregate is the most fundamental and widely used component of construction. It is used as an unbound material which constitutes about 100% of the volume of base courses, 95 to 93% of the volume of asphalt and about 85 to 75% of the volume of Portland cement concrete. Aggregate is exposed to a number of physical and chemically degrading forces during processing, transporting, and construction. As the main load carrying component of unbound and bituminous and Portland cement concretes, the aggregate must be clean, hard, sound, durable, resistant to abrasion, uniform in quality and free of any detrimental quantities of soft, friable, thin, elongated or laminated pieces, disintegrated material, alkali or other deleterious substance. For assesing the abrasion resistance of aggregates, the most common method is the Los Angeles abrasion and impact test (LAAI) which determines the relative competence or resistance to abrasion of the aggregates.In this study, four limestones, four travertines, three crystalline marbles and one andesite were tested to evaluate the correlations between the LAAI values and the physical properties covering bulk density, Schmidt hardness, shore hardness, P-wave velocity and mechanical properties such as uniaxial compressive strength, point load index, and indirect tensile strength of rocks. Since these properties are of great importance as a source of aggregates, tests on the rock can give an indication of the strength of the aggregates.The above rock properties were determined through standard testing methods in order to investigate the correlation between LAAI and each rock property by using regression analysis. A simple equation predicting the LAAI value based on each rock property was suggested. From the statistical tests, rock properties were found to be significant in estimating the LAAI values of rocks.     

研磨法检测煅烧氧化铝的原晶粒度

原晶粒度是煅烧氧化铝重要性能指标之一 ,借鉴美国铝业公司的研磨法 ,用BI XDC型美国粒度仪 ,对高温氧化铝的原晶粒度进行了测试 ,测试结果完全符合原晶粒度的定义 ,可直接应用于科研生产。     

Abrasion-induced microstructural changes and material removal mechanisms in squeeze-cast aluminium alloy-silicon carbide composites

An attempt has been made to understand wear-induced subsurface microstructural changes and material removal mechanisms in squeeze-cast BS LM11 alloy dispersed with 10 vol% SiC. Particles as well as fibres of SiC were separately dispersed in the alloy matrix to determine the influence of shape of the dispersoid on the abrasion behaviour of the latter. Abrasion tests were conducted on a standard rubber wheel abrasion test apparatus. Silica sand was used as the abrasive medium. Abrasive wear rates of the specimens were found to decrease gradually with the number of test intervals until a steady state value was attained. This was attributed to the protrusion of the reinforcement phase and abrasion-induced work hardening of the matrix in regions close to the abraded surface. The dispersoid/matrix interface as well as the shape of the dispersoid was found to influence the abrasion rate of the composites. A poor dispersoid/matrix interface led to higher rate of abrasion due to pull-out of the dispersoid. On the other hand, good bonding between the dispersoid and the matrix helped the dispersoid phase to be retained by the matrix, offering reduced rate of abrasion.     

Effect of cavity preparation method on microtensile bond strength of a self-etching primer vs phosphoric acid etchant to enamel

This study evaluated the effect of cavity preparation using air abrasion or carbide bur on bond strength to enamel treated with a self-etching primer (Tyrian SPE) or a phosphoric acid etchant. Twenty-four molars were divided into three groups: high-speed; standard handpiece (ST air abrasion) or supersonic handpiece (SP air abrasion) of the same air-abrasive system. The enamel surfaces were treated with one of the two etchants and the same adhesive agent One Step Plus, and then composite buildups were done with Filtek Z250. After 24 h at 37 °C, beams (0.8 mm²) were obtained and subjected to tensile stress in a universal testing machine (0.5 mm/min). The data were submitted to analysis of variance and Tukey’s test (P < 0.05). For the conditioning agents, it was observed that the specimens conditioned with phosphoric acid presented superior results than the specimens that used Tyrian SPE. For the preparation techniques, it was verified that the SP air abrasion groups showed the highest bond strengths and carbide-bur groups presented the lowest bond strengths when the specimens were conditioned with Tyrian SPE. It can be concluded that the influence of the cavity preparation method was dependent on the conditioning system used, only when using carbide-bur preparation technique.