The aim of the submitted work is to study the influence of applied loads ranging from 0.09807 N to 0.9807 N on measured values of micro-hardness of heat treated carbon steel. The influence of applied ...load on measured value of micro-hardness was evaluated by Meyer's index n, PSR method and by Analysis of Variance (ANOVA). The influence of the load on the measured value of micro-hardness is statistically significant and the relationship between applied load and micro-hardness manifests the moderate reverse ISE. As far as the relationship between measured hardness and load independent "true hardness", the best fit was obtained between HV0.05 and "true hardness" calculated using index a sub(2).
The Influence of the Load on the Hardness The objective of the submitted paper is to analyze the influence of the load on the calibration of micro-hardness and hardness testers. The results were ...validated by Measurement Systems Analysis (MSA), Analysis of Variance (ANOVA) and Z-score. The relationship between the load and micro-hardness in calibration of micro-hardness testers cannot be explained by Kick's Law (Meyer's index "n" is different from 2). The conditions of Kick's Law are satisfied at macro-hardness calibration, the values of "n" are close to 2, regardless of the applied load. The apparent micro-hardness increases with the increase of the load up to 30 g; the reverse indentation size effect (ISE) behavior is typical for this interval of the loads. The influence of the load on the measured micro-hardness is statistically significant for majority of calibrations.
The aim of the submitted work is to study the influence of applied loads ranging from 0.09807 to 0.9807 N on microhardness. Whereas standard reference block with defined specified hardness and its ...uncertainty was used as a specimen, individual measurement involved indirect calibration of tester. The measurement was repeated for estimation of the variability of results. The influence of applied load on the measured value of microhardness was evaluated by Meyer’s index
n
, PSR method and by analysis of variance and was different for individual “measurements” despite the identical specimen, method, equipment and appraiser. The uncertainty of measured values of the hardness partly obscures the occurrence and type of indentation size effect.
The object of submitted work is to analyze the influence of the rotation of the indenter (diamond pyramid) and test force on the result of Vickers hardness tester calibration using uncertainty ...analysis, Measurement systems analysis (MSA), analysis of variance (ANOVA) and Z-score. The rotation anmgle of indenter affects the values of hardness, repeatability rrel, maximal error Erel and relative expanded uncertainty Urel. The significance of the angle of indenter on the hardness and observed parameters of calibration no such as it of test force, but not negligible.
The results of the fluidity test obtained by computer simulations (software NovaFlow&Solid) and by the experiment were compared. The horizontal mold with three canals was an experimental device that ...provides true or real values of the fluidity. Al-Si alloy with Si content between 5 and 12 % wt. was an experimental material. The casting temperatures ranged between 605°C and 830°C and the casting velocity between 100 and 400 g s-1. Pursuant to close results between true tests of the fluidity in a horizontal three-channel mold and the results of computer simulation, the model was designed. Subsequently, the model was processed by multiple regression analysis. A calculated equation was verified by comparing with the results of true fluidity in conclusion. The difference is not statistically significant.
The literature regarding the Reverse Indentation Size Effect (RISE) is scarce, the occurrence of which is assumed for plastic materials, including metals. The content of this article is to study the ...relationship between applied load and measured values of the Vickers micro-hardness of 19 metals with different types of lattices, measured with a Hanemann tester. The values of the load ranged between 0.09807 N (10 g) and 0.9807 N (100 g). The size and character of the Indentation Size Effect (ISE) were evaluated by Meyer’s power law (index n), Proportional Specimen Resistance (PSR), and Hays—Kendall methods. Meyer’s index n ranged between 1.65 for Mo and 2.44 for Ni. A correlation was found between the micro-hardness and Meyer’s index for metals with FCC and HCP lattices. The measured value of Vickers micro-hardness is influenced by the size and nature of the ISE. If this is not taken into account, it may be misleading. For this reason, we recommend using the “true hardness”, determined by the presented method.
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