The aim of the submitted work is to study the relationship between the local deformation and the ... more The aim of the submitted work is to study the relationship between the local deformation and the indentation size effect (ISE). A local value of reduction of the area (Z) was used as the measure of the deformation. Applied loads in the micro-hardness test ranged between 0.09807 to 0.9807 N. The micro-hardness was measured on the cross section in the longitudinal axis of the fractured sample after the uniaxial tension test. The material of the sample was 99.5% aluminium. The influence of both load and deformation on the ISE was evaluated by the analysis of variance (ANOVA). The influence of the load was also evaluated by Meyer’s index n, PSR method, and Hays–Kendall approach. The influence of both factors on the measured value of micro-hardness and therefore on the ISE is statistically significant. The ISE is normal in the areas with high deformation, on the contrary, in areas with low deformation, it has a “reverse” character. The difference between load independent “true hardness” ...
This article deals with the design of appropriate measures that had to be taken for the implement... more This article deals with the design of appropriate measures that had to be taken for the implemented measurement system. The measurement result was significantly negatively affected by several factors. Forty-five samples of shafts used in the production of surgical drills were measured. Measurements were performed by metrological appraisers with a calibrated digital micrometer. Measurement and subsequent data processing revealed low process capability (CP and PP indices). A large portion of the shafts had an observed size below the lower specific limit (LSL). Therefore, it was necessary to take corrective action. This paper focuses on the corrective measures implemented in the measurement system. The micrometer met the requirements of the standard and was metrologically capable. The shafts were measured by eight metrological appraisers, so attention was focused on the potential impact of the metrological appraiser. The measured data were evaluated by uncertainty analysis, paired t-te...
The literature regarding the Reverse Indentation Size Effect (RISE) is scarce, the occurrence of ... more 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”, determine...
Industries demand that their products are high quality with the least number of defects due to th... more Industries demand that their products are high quality with the least number of defects due to the rapid improvement in manufacturing technology. Quality is a critical criterion for evaluation in manufacturing firms. The production of a final product that can meet customer requirements is essential in a sustainable supply chain system to reduce costs, increase productivity and provide high-quality products. The aim of the study is to identify the root cause of defects emerging in the production process of prestressed railway concrete sleepers. Ishikawa diagram and Pareto analysis were used to identify the root cause. The results showed that the cause of the faulty concrete sleeper is the breaking of the bolts, which are supplied by the external provider. Since the supplier refused to accept the complaint, chemical analysis and measuring of hardness and microhardness of bolts were realized. It showed that the hardness of the bolts does not achieve the values, which should be achieved...
The purpose of the paper was to evaluate the probability of the top event in the fluidity test by... more The purpose of the paper was to evaluate the probability of the top event in the fluidity test by Fault Tree Analysis (FTA). One of the important tests used in the foundry practice is the test of the fluidity. Fluidity is the ability of the molten metal to fill the cavity of the molds and create a cast. The AlSi10MgMn (EN 1706) alloy with 5 or 10.54 % of silica was the experimental material. The melted alloy was cast into "horizontal" three-channel mold to test its fluidity. The pouring temperatures were between 605 and 830 °C. In some cases, the experiment was not successful, for a some reasons. This fact led to a waste of time, energy, potential risk of accident, confusion among participants, especially "beginners" founders and became an impulse for the analysis of creation and possible events of fault for the fluidity test using the FTA. It has been found that for the probability of the top event in examined process was disproportionately high (0.29824). The M...
European Union legislation requires organizations to assess their processes in the context of ris... more European Union legislation requires organizations to assess their processes in the context of risk management. The main task of risk management is to manage all risks that can significantly affect the outcome of processes. The article is focused on risk evaluation in pressure leaching at elevated temperature using the method Fault Tree Analysis (FTA). The effectivity of pyrite and arsenic pyrite decomposition by oxidative pressure leaching is influenced by the duration of the process, by the temperature, concentration of the leaching solution and by a density of the slurry. It was found that, under equitable conditions, the arsenic pyrite decomposes more intensely than pyrite. Under laboratory conditions, leaching is performed in an autoclave. Due to the aggressive environment, increased pressure and temperature, process failure is possible. Its probability was calculated by FTA. It has been found that the probability of the top event in the examined process was disproportionately h...
The Vickers test is the standard method for measuring the hardness of metals, particularly those ... more The Vickers test is the standard method for measuring the hardness of metals, particularly those with extremely hard surfaces: the surface is subjected to a standard pressure for a standard length of time by means of a pyramid-shaped diamond with vertex angle 136°. The diagonal of the resulting indention is measured under a microscope. The Vickers testing method is the most accurate and sensitive hardness test method. It is unsuitable for inhomogeneous and coarse-grained materials. Thoroughly prepared surface before test is required. The Vickers test does not deteriorate the surface of final product as much as Brinell test.
The aim of submitted work is to search the softening and melting temperature of archeometallurgy ... more The aim of submitted work is to search the softening and melting temperature of archeometallurgy bloomery and blast furnace slag using high – temperature microscope. The high values of melting temperature of bloomery slag is a result of secondary oxidation of wustite in the chamber of a microscope. The melting temperature increases with an increase in SiO2 and decreases with increasing basicity of the slag.
The aim of this paper was to examine the surface tension of the melt mixture of salts NaCl and KC... more The aim of this paper was to examine the surface tension of the melt mixture of salts NaCl and KCl at temperatures 750, 800 and 850 °C by maximum bubble pressure method. Some difference between measured values of the surface tension as dependence on the method of calculation was observed. This difference results from the diameter of used capillary and does not depend on the temperature. The differences between experimentally measured values of surface tension and literary sources are trivial. The experimental results are in accordance with the literature data confirming unsuitability of maximum bubble pressure method for measurement of the melt density. The experimental result will be used as a base for the study of melt salts ternary systems. On the other side maximum bubble pressure method is the most suitable method for measurement of surface tension of melt salts, but it is unsuitable for measurement of the melt density.
Measurement system analysis (MSA) was used for estimation of hardness (HBS) measurement system ca... more Measurement system analysis (MSA) was used for estimation of hardness (HBS) measurement system capability. The time dependence of capability was evaluated. Experimental material Cu-Zn-Al cast alloy was used as shape memory alloy. The average and range method with 2 appraisers, 10 samples and 3 trials (indentations). was used to quantify repeatability (% EV), reproducibility (% AV) and part variation (% PV – variation between samples). The measurement was repeated 5 times in intervals of 7 days. As the values of %GRR are between 89.4% and 63.7% and values of “ndc” between 0.71 and 1.71 the used hardness measurement system is not capable and it depends heavily on the long-term variability.
A Brinell hardness tester with carbide and steel balls was calibrated and thereafter the hardness... more A Brinell hardness tester with carbide and steel balls was calibrated and thereafter the hardness of ten samples of steel STN 41 1600 was measured by four appraisers. The uncertainty of calibration and of the hardness measurement were calculated. The results obtained with carbide and steel balls were confronted using uncertainty analysis, measurement systems analysis (MSA), analysis of variance (ANOVA), unpaired t-test and Z-score. The calibrated hardness tester is not considered satisfactory because the values of relative expanded uncertainty of calibration (relative maximum permissible error) and maximum error exceed the values permitted by the standard for both balls. The statistically significant difference between the uncertainties and relative maximum error obtained by carbide and steel balls was not confirmed neither at calibration nor at measurement of steel sample hardness. Measurement system analysis confirmed some influence of used ball materials on the results of individ...
The objective of submitted work is to analyze the i nfluence of the load on the micro-hardness of... more The objective of submitted work is to analyze the i nfluence of the load on the micro-hardness of Cu, Al, Co, Ni, Fe, Zn and glass. The results were validated by Measurement Systems Analysis (MSA), Analysis of Variance (ANOVA) and Z-score. The relationship between the load and micro-hardness for measured materials can not be ex plained by Kick’s Law (the value of Meyer’s index “n” is different from 2). The micro-h ardness increases with increasing load up to 0.2942 N; the reverse ISE behavior with n >2 is typ ical for this load interval. The influence of the load on the micro-hardness is statistically sig nificant. The uncertainty decreases with increasing load and micro-hardness and of material. The capability of measurement process increases with increasing micro-hardness or Meyer’s index “n”. All results of Z-score are satisfactory.
Iron, often present in secondary material (scrap) forms brittle and hard needles in Al-Si alloys.... more Iron, often present in secondary material (scrap) forms brittle and hard needles in Al-Si alloys.These particles decrease the mechanical properties of castings. A reliable and economic method of iron elimination from aluminium alloys has not been well-known yet in metallurgical practice. The influence of nickel as an iron corrector (up to 0.7 %) and iron (up to 2.5 %) on the fluidity, microstructure and mechanical properties of the Al alloy with 9.75 % Si, 0.2 % Mg was evaluated. The presence of Ni results in shortening of the needles, but the segmentation of β needles was not observed. Improvement of mechanical properties was observed despite of low affecting of microstructure.
The objective of the article is to analyze results of indirect calibration of three microhardness... more The objective of the article is to analyze results of indirect calibration of three microhardness testers. The calibration was carried out by four ap praisers using three reference blocks. The results were evaluated according to standard STN EN ISO 6507-2:2005 and by uncertainty analysis, unpaired t-test, the Analysis of Variance (ANOVA) and Z-score. All calibrated testers do not satisfy the condition of resolution. Only 5 calibrations (13.9 %) meet the conditions of standard. According to Analysis of Variability (AN OVA), the influence of appraisers on the microhardness is significant, especially for “soft” reference block and for tester No. 1. Maximum number of statistically significant differe nces between mean microhardness, measured by one appraiser and specified microhardness of correspondent standard was obtained at calibration of tester No. 2 by t-test. Unsatisfa ctory or conditionally satisfactory values of zscore were observed at calibration of tester No. 3, but the values...
Deposits of old blast-furnace slag are an environmental problem. The slag’s hardness is an import... more Deposits of old blast-furnace slag are an environmental problem. The slag’s hardness is an important for calculation of the energy cost for crushing and grinding process. Due to its porosity, measurement of the (macro) hardness is. To adapt the dimensions of the indentations to the character of the slag, it is necessary to apply loads in the range of micro-hardness. The purpose of this paper is to evaluate the influence of load on the micro-hardness - the Indentation Size Effect (ISE) using Meyer’s, Hays-Kendall and PSR methods. ISE for all samples is “normal”, the slag’s basicity affects micro-hardness and ISE.
ABSTRACT The aim of the submitted work is to study the influence of applied loads (test forces) b... more ABSTRACT The aim of the submitted work is to study the influence of applied loads (test forces) between 0.09807 and 2.9421 N on the measured value of micro-hardness of sintered Fe/3.3 wt-%Cu + CnHm. The Indentation Size Effect (ISE), i.e. the influence of the load on the micro-hardness is expected. The results were evaluated by Meyer’s index n, t-test, and non-parametric tests. The applied load has a statistically significant influence on the type and size of the ISE. Tested sintered material shows ‘normal’ ISE with Meyer’s index n = 1.7588.
The aim of the submitted work is to study the relationship between the local deformation and the ... more The aim of the submitted work is to study the relationship between the local deformation and the indentation size effect (ISE). A local value of reduction of the area (Z) was used as the measure of the deformation. Applied loads in the micro-hardness test ranged between 0.09807 to 0.9807 N. The micro-hardness was measured on the cross section in the longitudinal axis of the fractured sample after the uniaxial tension test. The material of the sample was 99.5% aluminium. The influence of both load and deformation on the ISE was evaluated by the analysis of variance (ANOVA). The influence of the load was also evaluated by Meyer’s index n, PSR method, and Hays–Kendall approach. The influence of both factors on the measured value of micro-hardness and therefore on the ISE is statistically significant. The ISE is normal in the areas with high deformation, on the contrary, in areas with low deformation, it has a “reverse” character. The difference between load independent “true hardness” ...
This article deals with the design of appropriate measures that had to be taken for the implement... more This article deals with the design of appropriate measures that had to be taken for the implemented measurement system. The measurement result was significantly negatively affected by several factors. Forty-five samples of shafts used in the production of surgical drills were measured. Measurements were performed by metrological appraisers with a calibrated digital micrometer. Measurement and subsequent data processing revealed low process capability (CP and PP indices). A large portion of the shafts had an observed size below the lower specific limit (LSL). Therefore, it was necessary to take corrective action. This paper focuses on the corrective measures implemented in the measurement system. The micrometer met the requirements of the standard and was metrologically capable. The shafts were measured by eight metrological appraisers, so attention was focused on the potential impact of the metrological appraiser. The measured data were evaluated by uncertainty analysis, paired t-te...
The literature regarding the Reverse Indentation Size Effect (RISE) is scarce, the occurrence of ... more 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”, determine...
Industries demand that their products are high quality with the least number of defects due to th... more Industries demand that their products are high quality with the least number of defects due to the rapid improvement in manufacturing technology. Quality is a critical criterion for evaluation in manufacturing firms. The production of a final product that can meet customer requirements is essential in a sustainable supply chain system to reduce costs, increase productivity and provide high-quality products. The aim of the study is to identify the root cause of defects emerging in the production process of prestressed railway concrete sleepers. Ishikawa diagram and Pareto analysis were used to identify the root cause. The results showed that the cause of the faulty concrete sleeper is the breaking of the bolts, which are supplied by the external provider. Since the supplier refused to accept the complaint, chemical analysis and measuring of hardness and microhardness of bolts were realized. It showed that the hardness of the bolts does not achieve the values, which should be achieved...
The purpose of the paper was to evaluate the probability of the top event in the fluidity test by... more The purpose of the paper was to evaluate the probability of the top event in the fluidity test by Fault Tree Analysis (FTA). One of the important tests used in the foundry practice is the test of the fluidity. Fluidity is the ability of the molten metal to fill the cavity of the molds and create a cast. The AlSi10MgMn (EN 1706) alloy with 5 or 10.54 % of silica was the experimental material. The melted alloy was cast into "horizontal" three-channel mold to test its fluidity. The pouring temperatures were between 605 and 830 °C. In some cases, the experiment was not successful, for a some reasons. This fact led to a waste of time, energy, potential risk of accident, confusion among participants, especially "beginners" founders and became an impulse for the analysis of creation and possible events of fault for the fluidity test using the FTA. It has been found that for the probability of the top event in examined process was disproportionately high (0.29824). The M...
European Union legislation requires organizations to assess their processes in the context of ris... more European Union legislation requires organizations to assess their processes in the context of risk management. The main task of risk management is to manage all risks that can significantly affect the outcome of processes. The article is focused on risk evaluation in pressure leaching at elevated temperature using the method Fault Tree Analysis (FTA). The effectivity of pyrite and arsenic pyrite decomposition by oxidative pressure leaching is influenced by the duration of the process, by the temperature, concentration of the leaching solution and by a density of the slurry. It was found that, under equitable conditions, the arsenic pyrite decomposes more intensely than pyrite. Under laboratory conditions, leaching is performed in an autoclave. Due to the aggressive environment, increased pressure and temperature, process failure is possible. Its probability was calculated by FTA. It has been found that the probability of the top event in the examined process was disproportionately h...
The Vickers test is the standard method for measuring the hardness of metals, particularly those ... more The Vickers test is the standard method for measuring the hardness of metals, particularly those with extremely hard surfaces: the surface is subjected to a standard pressure for a standard length of time by means of a pyramid-shaped diamond with vertex angle 136°. The diagonal of the resulting indention is measured under a microscope. The Vickers testing method is the most accurate and sensitive hardness test method. It is unsuitable for inhomogeneous and coarse-grained materials. Thoroughly prepared surface before test is required. The Vickers test does not deteriorate the surface of final product as much as Brinell test.
The aim of submitted work is to search the softening and melting temperature of archeometallurgy ... more The aim of submitted work is to search the softening and melting temperature of archeometallurgy bloomery and blast furnace slag using high – temperature microscope. The high values of melting temperature of bloomery slag is a result of secondary oxidation of wustite in the chamber of a microscope. The melting temperature increases with an increase in SiO2 and decreases with increasing basicity of the slag.
The aim of this paper was to examine the surface tension of the melt mixture of salts NaCl and KC... more The aim of this paper was to examine the surface tension of the melt mixture of salts NaCl and KCl at temperatures 750, 800 and 850 °C by maximum bubble pressure method. Some difference between measured values of the surface tension as dependence on the method of calculation was observed. This difference results from the diameter of used capillary and does not depend on the temperature. The differences between experimentally measured values of surface tension and literary sources are trivial. The experimental results are in accordance with the literature data confirming unsuitability of maximum bubble pressure method for measurement of the melt density. The experimental result will be used as a base for the study of melt salts ternary systems. On the other side maximum bubble pressure method is the most suitable method for measurement of surface tension of melt salts, but it is unsuitable for measurement of the melt density.
Measurement system analysis (MSA) was used for estimation of hardness (HBS) measurement system ca... more Measurement system analysis (MSA) was used for estimation of hardness (HBS) measurement system capability. The time dependence of capability was evaluated. Experimental material Cu-Zn-Al cast alloy was used as shape memory alloy. The average and range method with 2 appraisers, 10 samples and 3 trials (indentations). was used to quantify repeatability (% EV), reproducibility (% AV) and part variation (% PV – variation between samples). The measurement was repeated 5 times in intervals of 7 days. As the values of %GRR are between 89.4% and 63.7% and values of “ndc” between 0.71 and 1.71 the used hardness measurement system is not capable and it depends heavily on the long-term variability.
A Brinell hardness tester with carbide and steel balls was calibrated and thereafter the hardness... more A Brinell hardness tester with carbide and steel balls was calibrated and thereafter the hardness of ten samples of steel STN 41 1600 was measured by four appraisers. The uncertainty of calibration and of the hardness measurement were calculated. The results obtained with carbide and steel balls were confronted using uncertainty analysis, measurement systems analysis (MSA), analysis of variance (ANOVA), unpaired t-test and Z-score. The calibrated hardness tester is not considered satisfactory because the values of relative expanded uncertainty of calibration (relative maximum permissible error) and maximum error exceed the values permitted by the standard for both balls. The statistically significant difference between the uncertainties and relative maximum error obtained by carbide and steel balls was not confirmed neither at calibration nor at measurement of steel sample hardness. Measurement system analysis confirmed some influence of used ball materials on the results of individ...
The objective of submitted work is to analyze the i nfluence of the load on the micro-hardness of... more The objective of submitted work is to analyze the i nfluence of the load on the micro-hardness of Cu, Al, Co, Ni, Fe, Zn and glass. The results were validated by Measurement Systems Analysis (MSA), Analysis of Variance (ANOVA) and Z-score. The relationship between the load and micro-hardness for measured materials can not be ex plained by Kick’s Law (the value of Meyer’s index “n” is different from 2). The micro-h ardness increases with increasing load up to 0.2942 N; the reverse ISE behavior with n >2 is typ ical for this load interval. The influence of the load on the micro-hardness is statistically sig nificant. The uncertainty decreases with increasing load and micro-hardness and of material. The capability of measurement process increases with increasing micro-hardness or Meyer’s index “n”. All results of Z-score are satisfactory.
Iron, often present in secondary material (scrap) forms brittle and hard needles in Al-Si alloys.... more Iron, often present in secondary material (scrap) forms brittle and hard needles in Al-Si alloys.These particles decrease the mechanical properties of castings. A reliable and economic method of iron elimination from aluminium alloys has not been well-known yet in metallurgical practice. The influence of nickel as an iron corrector (up to 0.7 %) and iron (up to 2.5 %) on the fluidity, microstructure and mechanical properties of the Al alloy with 9.75 % Si, 0.2 % Mg was evaluated. The presence of Ni results in shortening of the needles, but the segmentation of β needles was not observed. Improvement of mechanical properties was observed despite of low affecting of microstructure.
The objective of the article is to analyze results of indirect calibration of three microhardness... more The objective of the article is to analyze results of indirect calibration of three microhardness testers. The calibration was carried out by four ap praisers using three reference blocks. The results were evaluated according to standard STN EN ISO 6507-2:2005 and by uncertainty analysis, unpaired t-test, the Analysis of Variance (ANOVA) and Z-score. All calibrated testers do not satisfy the condition of resolution. Only 5 calibrations (13.9 %) meet the conditions of standard. According to Analysis of Variability (AN OVA), the influence of appraisers on the microhardness is significant, especially for “soft” reference block and for tester No. 1. Maximum number of statistically significant differe nces between mean microhardness, measured by one appraiser and specified microhardness of correspondent standard was obtained at calibration of tester No. 2 by t-test. Unsatisfa ctory or conditionally satisfactory values of zscore were observed at calibration of tester No. 3, but the values...
Deposits of old blast-furnace slag are an environmental problem. The slag’s hardness is an import... more Deposits of old blast-furnace slag are an environmental problem. The slag’s hardness is an important for calculation of the energy cost for crushing and grinding process. Due to its porosity, measurement of the (macro) hardness is. To adapt the dimensions of the indentations to the character of the slag, it is necessary to apply loads in the range of micro-hardness. The purpose of this paper is to evaluate the influence of load on the micro-hardness - the Indentation Size Effect (ISE) using Meyer’s, Hays-Kendall and PSR methods. ISE for all samples is “normal”, the slag’s basicity affects micro-hardness and ISE.
ABSTRACT The aim of the submitted work is to study the influence of applied loads (test forces) b... more ABSTRACT The aim of the submitted work is to study the influence of applied loads (test forces) between 0.09807 and 2.9421 N on the measured value of micro-hardness of sintered Fe/3.3 wt-%Cu + CnHm. The Indentation Size Effect (ISE), i.e. the influence of the load on the micro-hardness is expected. The results were evaluated by Meyer’s index n, t-test, and non-parametric tests. The applied load has a statistically significant influence on the type and size of the ISE. Tested sintered material shows ‘normal’ ISE with Meyer’s index n = 1.7588.
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