9762 papers found
Center for Measurement Standards (CMS) had established a thin-film indentation testing system based on Akashi MZT-522. The electronic balance was made use of calibrating the testing force and the internal depth sensor was calibrated by laser hologauge. Five other uncertainty was also evaluated in the paper. Finally, the uncertainty of the thin-film indentation testing system reached a total of 5.02 %.
Rockwell hardness (HR) is a valuable and widely used indentation hardness test for evaluating mechanical properties of metallic materials. For the Rockwell scales that use a ball indenter, either a steel or tungsten carbide (WC) ball indenter is permitted to be used in the test method standards of ASTM International and International Organization for Standardization (ISO). However, significant differences occur in Rockwell hardness tests depending on whether a steel or WC ball is used. In this paper, finite element analysis (FEA) is used to simulate the HR indentation process. The effects of...
The paper describes calibration method of portable Brinell hardness testers, which have been manufactured for many years and used popularly in China, especially used in testing hardness of ferrous metals. A series of experiment have been done concerning hardness levels for calibration, thickness of hardness blocks, supports of the blocks, diameters of ball indenters and touch-method between the block and the support. Based on result obtained from tests mentioned above, it is given that specifications of portable Brinell hardness testers including indication error of 7%, repeatability of 4%,...
Hardness tests have always been important to conclude on specific mechanical properties of materials in a fast and economic manner, i.e. in a (quasi) non destructive test. This paper has its focus on the most recent test method, the dynamic rebound hardness test method after D. Leeb. The EQUOTIP, Leeb's original instrument, is fully discussed and newest improvements are presented. So far, PROCEQ SA, Swiss manufacturer of the instruments, maintained and protected the constancy of the L-Value over the last 30 years. Recent round robin results show the way, where standardization work can be...
This bilateral comparison in HRC between National Metrology Institute of Japan, (NMIJ) and National Institute of Metrology (Thailand), (NIMT) was done in order to establish the hardness scales of NIMT and confirm their accuracy, which was designated by NIMT ( 0.45 HRC). The hardness blocks of 20 HRC, 30 HRC, 40 HRC and 60 HRC, which all have uniformity within 0.1 HRC according to EN ISO 6508-3, were used in this comparison. They were measured by NMIJ and NIMT with different conditions in order to indicate the performance of machines and hardness scales. Agreement of machine performance is...
In the framework of the Working Group on Hardness (WGH) of the Consultative Committee for Mechanical Measurements (CCM) in the year 2003 the key comparison Vickers was finished. In the comparison the hardness laboratories of 10 national metrology institutes participated: IMGC (Italy), NIST (USA), INMETRO (Brazil), NIM (P.R. China), KRISS (Republic of Korea), NMIJ (Japan), CMI (Czech Republic), GUM (Poland), NPL (U.K.), and PTB (Germany) served as the pilot laboratory. The comparison of the Vickers primary hardness standard machines was carried out with three sets of hardness reference blocks...
In the early of 2003, the traceability system of the Rockwell hardness standard have been developed in Japan. The National Metrology Institute of Japan (NMIJ) started to provide the national primary hardness standards, one of which is the hardness reference blocks, and the other one is the accreditation of the Rockwell hardness tester. In this paper, we present the detail of uncertainty transfer between the NMIJ and the secondary standard laboratories.
The mechanical properties of adhesives are determined either from bulk material samples from adhesively bonded joints. For many years there has been controversy as to whether the mechanical properties obtained through testing bulk material are representative of the adhesive in its thin-film form. The use of adhesive bonding as a method of joining structural members in advanced structures is increasing. A major advantage of adhesive bonding is that it enables dissimilar materials to be joined and reduces the localized stresses encountered when using mechanical fastening such as bolts and...
Diamond indenters used in a Rockwell hardness tester can dramatically affect the performance of the test. For this reason, it is important to find a method that can characterise the indenter. Current methods of verifying diamond indenter geometry have failed to thoroughly predict the performance when in use in the Rockwell tester. The paper addresses a possible method to use depth data during the test to characterise the indenter.