金属洛氏硬度计测量不确定度评定

通过金属洛氏硬度计测量的实例，表述并讨论金属洛氏硬度计测量不确定度的评定方法     

金属洛氏硬度计的测量不确定度分析

金属洛氏硬度计适用于各种金属材料的硬度测定。在使用过程当中，由于受各种因素的影响，硬度计难免会出现误差。文章根据金属洛氏硬度计检定规程的相关条件及规定，对金属洛氏硬度计其中的HR15N（T）标尺进行了相应的误差分析，以便实现对该装置的示值误差计算更加准确可靠。     

市场监管总局批准建立2项国家计量基准

<正>近日,市场监管总局陆续发布公告,批准建立“金属洛氏硬度副基准装置”“辐射热流基准装置”2项国家计量基准。金属洛氏硬度副基准装置“砸”金属知软硬,金属洛氏硬度副基准装置是国家硬度基准的重要组成部分,并作为基准装置的备份,可为工作级台式和携带式金属洛氏硬度计、硬度计压头等提供最高精度级别的参考源。     

浅析洛氏硬度计常见故障及调修

金属洛氏硬度计适用于各种金属材料的硬度测定,广泛应用于机械加工、五金、饮用水等行业。本文主要对洛氏硬度计的常见故障进行分析并调修。     

金属洛氏硬度计测量不确定度评定

本文介绍了金属洛氏硬度计的测量不确定度评定。     

金属洛氏硬度计常见故障和误差产生原因及排除方法

本文主要介绍了金属洛氏硬度计常见故障和误差产生原因及排除方法。     

金属洛氏硬度计的故障原因分析及排除方法

文章从专业角度分析金属洛氏硬度计在计量检定过程中,产生误差的原因,并给出排除误差的方法。     

金属洛氏硬度计示值误差测量不确定度评定报告

正一、概述1.测量方法依据JJG112-2013《金属洛氏硬度计检定规程》。2.环境条件温度:10℃~35℃,校准时周围环境应清洁、无振动、无腐蚀性气体。3.测量标准标准洛氏硬度块(均匀度:0.2HR~0.5HR,上级证书给出)。4.被测对象金属洛氏硬度计(最大允许示值误差:±1.5HR~±2.0HR)。     

浅谈JJG112-2013和ASTM E18-15中关于硬度计校准部分的分析比较

对美标ASTM E18-15《金属材料洛氏硬度标准试验方法》中关于硬度计的校准和JJG 112-2013《金属洛氏硬度计检定规程》进行了分析比较,阐述了两者之间存在的主要差异。     

金属洛氏硬度计测量不确定度评定

本文通过测量金属洛氏硬度计(以C标尺为例),分析不确定度来源,给出测量不确定度方法。     

热交换器的分类及优缺点分析

热交换器是将不同温度介质之间的热量通过热传导的形式,由高温介质传递给低温介质,使介质达到生产所需温度的工艺设备,也可作为一种节能设备使用.通过对不同热交换器的结构分析,总结不同热交换器的优缺点、适用环境,为生产工艺设计人员及设备制造单位在选择可降低能耗、提高效率的设备上提供参考.     

聚苯胺及其复合物的制备和结构及形貌分析

通过化学氧化法分别制备盐酸,盐酸和十二烷基苯磺酸,碳纳米管(MWNTs-COOH)掺杂的聚苯胺,利用红外光谱,紫外光谱,扫描电子显微镜和透射电子显微镜对所制备聚苯胺的结构和形貌进行分析。分析不同掺杂物对聚苯胺的结构和形貌的影响;同时研究了超声波作用对聚苯胺形貌以及聚苯胺包裹MWNTs-COOH情况的影响。     

Modelling and computation of curing and damage of thermosets

The curing of thermosets is a complex process involving the transition from a fluid into a (visco-) elastic solid. This phase transition comes along with an increase in stiffness and a volume shrinkage of the polymer. The latter may lead to severe residual strains and stresses, which in turn can cause damage in the final, usually quasi-brittle material. In this contribution a constitutive model is developed which takes into account the curing of a thermosetting material together with the process-induced damage as resulting from curing shrinkage. The curing of the material is governed by a phenomenological hypoelastic constitutive equation which includes temporal evolutions for stiffness and volume shrinkage. Thermal and viscous effects are neglected in the present study. An isotropic gradient-enhanced damage model is adapted to describe the damage evolution. The curing-damage model is implemented into a finite element code and numerical examples for thermosetting materials demonstrate that the proposed model is capable to predict cure-induced damage in thermosets.     

Thermodynamic similarity and prediction of the properties and characteristics of substances and processes

Principles of the theory of thermodynamic similarity are considered in application to all aggregate states of a substance, including phase transitions, and to the change in dissipative structures in open systems.Translated from Inzhenerno-Fizicheskii Zhurnal, Vol. 53, No. 5, pp. 709–716, November, 1987.     

Mechanisms of Corosion and Oxidation of Metals and Alloys

Selected topics in field of the study of the mechanisms of corrosion and of oxidation of metals or alloys are presented. The first part reports a new model for the mechanism of the breakaway oxidation of ferritic stainless steels in water vapour. The second part is devoted to the physico‐chemical aspects of oxidation and presents experimental methods useful in the kinetic modelling applied to two alloys, the zircalloy‐4 and an AlMg5 % in the liquid state. In the third part the physical and numerical modelling of the stress corrosion cracking behaviour in face‐centered cubic (fcc) alloys is detailed, which enables the study of the influence of macroscopic parameters (such as the temperature or hydrogen activity) on the fracture process.     

碳化硼陶瓷增韧补强和致密化研究现状及其展望

碳化硼陶瓷具有极高的硬度,然而其低韧性、低抗弯强度、难以致密化限制了它的广泛应用.已有一些研究集中于碳化硼陶瓷增韧补强和致密化,对这一方面国内外研究进展进行了归纳与评述,阐明各种增韧补强和致密化方法的优缺点,提出碳化硼陶瓷增韧补强和致密化研究值得发展的一些方向.     

Measurement and analysis of elastic and anelastic properties of alumina and silicon carbide

Measurements of dynamic Young's modulus, E, and damping as a function of temperature, T, were made for alumina and silicon carbide. The Young's modulus data were compared with some from the literature, and analysed in terms of a theoretical framework relating the Debye temperature, θD, with the elastic constants. For both materials this analysis yielded a ratio T₀/θ_D which was near 0.4, where T₀ is an empirical fitting constant for the plot of (E(0)−E)/T versus 1/T (E(0) is the value of E at 0 K). The analysis of the damping data in terms of an Arrhenius type dependence led to effective activation energies near kT, where k is Boltzmann's constant. This revised version was published online in November 2006 with corrections to the Cover Date.     

Preparation and characterization of phosphate and arsenate apatites of strontium and their solid solutions

Samples of phosphate and arsenate apatites of strontium and six of their solid solutions, spread over the entire compositional range, were prepared by a wet method. They were characterized by chemical, X-ray, electron microscopic and infrared analyses. The validity of Vegard's law established the homogeneity of the solid solutions.     

检定和校准证书的异同与应用

本文介绍了检定和校准以及证书的两点相同、五点不同之处,说明了对检定证书和校准证书的正确应用。