rus
Issue #2/2021
А.S.Useinov, K.S.Kravchuk, Ye.V.Gladkih, S.V.Prokudin
Measurement of mechanical properties using instrumental indentation method in a large temperature range
Measurement of mechanical properties using instrumental indentation method in a large temperature range
DOI: 10.22184/1993-8578.2021.14.2.108.116
This paper presents a review of solutions for studying the physical and mechanical properties of materials by instrumental indentation method in a temperature region from -60 to +450 °C using "NanoScan-4D" series of hardness meters. Scientific timeliness is beyond dispute because the majority of professionals in materials science are trying to solve the problem of behavior of the materials in expanded conditions of operation. Reviewed are the peculiarities of additional modules used for measuring hardness at alternating temperature conditions and indicated the advantages and limits of the considered configurations. A special effort is made to comparison of measurement systems where uniform temperature is maintained both in a sample and instrument with the devices where a sample is heated only. Introduced are the examples of a wide range of materials studied in various temperature ranges. Besides, the temperature dependence of aluminium matrix composite materials hardness in the range from 20 to 350°С has been presented.
This paper presents a review of solutions for studying the physical and mechanical properties of materials by instrumental indentation method in a temperature region from -60 to +450 °C using "NanoScan-4D" series of hardness meters. Scientific timeliness is beyond dispute because the majority of professionals in materials science are trying to solve the problem of behavior of the materials in expanded conditions of operation. Reviewed are the peculiarities of additional modules used for measuring hardness at alternating temperature conditions and indicated the advantages and limits of the considered configurations. A special effort is made to comparison of measurement systems where uniform temperature is maintained both in a sample and instrument with the devices where a sample is heated only. Introduced are the examples of a wide range of materials studied in various temperature ranges. Besides, the temperature dependence of aluminium matrix composite materials hardness in the range from 20 to 350°С has been presented.
Теги: hardness indentation mechanical properties nanohardness meter индентирование механические свойства нанотвердометр твердость
MEASUREMENT OF MECHANICAL PROPERTIES USING INSTRUMENAL INDENTATION METHOD IN A LARGE TEMPERATURE RANGE
This paper presents a review of solutions for studying the physical and mechanical properties of materials by instrumental indentation method in a temperature region from –60 to +450 °C using "NanoScan-4D" series of hardness meters. Scientific timeliness is beyond dispute because the majority of professionals in materials science are trying to solve the problem of behavior of the materials in expanded conditions of operation. Reviewed are the peculiarities of additional modules used for measuring hardness at alternating temperature conditions and indicated the advantages and limits of the considered configurations. A special effort is made to comparison of measurement systems where uniform temperature is maintained both in a sample and instrument with the devices where a sample is heated only. Introduced are the examples of a wide range of materials studied in various temperature ranges. Besides, the temperature dependence of aluminium matrix composite materials hardness in the range from 20 to 350 °C has been presented.
А.S.Useinov*, Cand. of Sci. (Physics and Mathematics), First Deputy Director of FSBI TISNCM, (ORCID: 0000-0002-9937-0954), Troitsk, Russia, K.S.Kravchuk*, Cand. of Sci. (Physics and Mathematics), Researcher, Troitsk, Russia, Ye.V.Gladkih*, Junior Researcher, Troitsk, Russia, S.V.Prokudin*, Junior Researcher, Troitsk, Russia
DOI: 10.22184/1993-8578.2021.14.2.108.116
Получено: 29.03.2021 г.
INTRODUCTION
Nowadays, instrumental nanoindentation is one of the most popular nondestructive methods to determine mechanical properties of any materials. The great success of this method can be explained by ease of use in comparison with usual tension and compression tests which require thoroughly treated samples and large quantity of the materials to be tested [1]. One of the reasons of popularity of nanohardness testers is the possibility to automatically collect and analyse data. After installing a sample and choosing the test software the user will obtain statistically processed data collected from a large area in a definitely short period of time.
It is well-known that mechanical properties of many materials are strongly dependent on temperature. Therefore, the coatings and bulky materials properties for high-temperature applications should be studied at the temperatures most closely approximated to the operating conditions.
It makes nanoindentation at controlled temperature to be a relevant method for industrial applications because of the explicit form to demonstrate behavior of materials at operating temperatures and conditions. From the scientific point of view, nanoindentation at controlled temperature is interesting because a small quantity of materials allows of choosing microstructural formations of interest in the material studied by this method with higher accuracy. It allows of studying kinetic aspects of physics of the materials by a new method and in the materials wherein the use of conventional methods would be impossible.
From technical viewpoint, the high-temperature nanoindetation has developed especially in last two decades. The essential progress is in both the materials used for making heater elements and casings of heating devices and in the indentor materials, depending on the specific working medium. However, the main problem of measurements at high or low temperatures is temperature gradients within devices or in sample-indenter contact area that lead to temperature drifts which are significantly distorting the results and make the quantitative measurements impossible.
To reduce the temperature drift, use is made of the materials characterised by a small or almost zero thermal expansion coefficient, also, the measurement system is configured so that the relative thermal expansions of the construction compensate each other while preserving the indentor contact area with th sample in the zero displacement zone.
Temperature differences in a contact area can be minimized by special design of a heater when a sample and an indenter have the same temperature during the indenting process. This problem is solved in the various way by different manufacturers (Fig.1). One of the solutions is a synchronous heating of the indenter and a sample by independent electrical (Fig.1a) and laser (Fig.1b) heaters. The second way is to create a heater systems so as to create a uniformly heated volume where a sample and indenter are located (Fig.1c).
Both ways allow of making a system with minimum temperature drifts and instrumental noise. Serial instruments equipped with diamond indenters have sample heating temperature range up to 500 °C. However, a study of iron-contained compositions has a limit connected with a danger of indenter destruction because of carbide formation at the interaction of carbon and iron.
Variants of temperature measurement methods using "NanoScan"
Domestic nanohardness testers "NanoScan" are serial devices intended for measurements of the physical and mechanical properties of materials in linear micro- and nanometer length scale (Fig.2). "NanoScan" serial devices have a module concept. The basic module of "NanoScan" series measures mechanical properties by instrumental indentation method according to recommendations of ISO 14577 and GOST Р 8.748-2011 standards in the wide range of loads [2-4].
A device may have one, two or three measuring modules depending on dimensions of chosen platform. Moreover, available are the additional modules such as optical microscope, optical confocal profilometer, scanning probe microscope module or Vickers micro-hardness tester. A model of "NanoScan-4D" nanohardness tester is listed in the National Register of Measuring Equipment (see the Certificate of Attendance of Measuring Equipment RU.C.28.002.A No.
63952). A scanning probe microscope – nanohardness tester is listed in the National Register of Measuring Equipment (see the Pattern Approval Certificate Measuring Instruments RU.C.27.004.A No. 36630/1).
Depending on "NanoScan-4D" model, it may be equipped with additional modules such as lateral loading detector, specimen stage with heating of samples, etc.
"NanoScan-4D" series makes use of several approaches to measure the mechanical properties at various temperatures.
Usage of a climate chamber
A compact "NanoScan-4D" model can be installed as a unit into the "heat-cold-moisture" climate chamber. This model is highly reliable and can be operated in a temperature range from –60 to +100 °C. A control workstation and an electronic control unit are placed outside on the working desk, and a carrying frame with an indenter module is placed inside the chamber.
The advantage of that approach is a possibility to measure samples of a significantly larger scale (up to 100 × 100 × 50 mm). As an example, Fig.4 indicates testing data of rather worn out automobile tires. The real and supposed parts of a complex elastic module and tangent of mechanical losses in the frequency range from 0.1 to 50 Hz [5, 6] have been measured in the temperature range from –60 to +60 °C.
Built-in specimen stage with Peltier elements
A principle diagram of such design is indicated in Fig.5 [7]. The advantage of Peltier elements usage is a low response to heating and cooling processes, and, accordingly, a fast stabilisation of the operation mode. The disadvantage of this design is a small size of a study sample and relatively narrow temperature range (from 2 to 60°C). This module can be used to study polymer materials, for example, polycarbonate, ultra-high-molecular-weight polyethylene (UHMWPE) and there analogies.
High-temperature specimen stage
One more solution to enlarge operation possibilities of "NanoScan-4D" serial devices is a built-in high-temperature specimen stage to heat samples (Fig.6). This device is intended to operate with the relatively small samples (no more than 15 × 15 × 5 mm in size) in the temperature range from 20 to +450 °C. The device has the upper and lower heaters that provide the uniform heating up of the working chamber volume where the study sample and indenter are placed.
A special ceramic heater, thermal shield, double-sided water cooling system and precision thermal controlled system make it possible to minimize temperature drifts during the measurements. Figure 7 shows the temperature drift diagram measured at melted quartz sample indenting loaded with 50 mN at a temperature of 400 °C. After thermal stabilization of a specimen stage, a thermal drift during a contact between a sample and the indenter does not exceed 0.06 nm/sec at constant loading of the indenter with an accuracy of dF=1 µN.
As an example how this module is used, it is possible to demonstrate a dependence of the hardness of nanostructured aluminium matrix composite materials versus temperature: test No.1 – along the extrusion axis, test No.2 – in the perpendicular direction to the extrusion axis [8]. Measurements of hardness were performed by the instrumental indentation method according to recommendations of GOST Р 8.748-2011 (ISO 14577-1:2002).
CONCLUSIONS
This paper presents a review of the technical solutions which can be applied for measuring physical and mechanical properties of the materials by the instrumental indentation method in temperature range from -60 to +450 °C using "NanoScan-4D" series nanohardness instruments. There is a wide choice of the instrument modules depending on specific tasks to be accomplished (see Table 1).
ACKNOWLEDGEMENTS
The authors thank to Mr Reshetov V.N. for the active participation in discussion of a design and methods to carrying up the high-temperature measurements using "NanoScan" serial devices. The research was carried out with the financial support of the Ministry of Education and Science of Russian Federation in a frame of National Assignment for FSBI TISNCM. ■
Declaration of Competing Interest. The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper.
This paper presents a review of solutions for studying the physical and mechanical properties of materials by instrumental indentation method in a temperature region from –60 to +450 °C using "NanoScan-4D" series of hardness meters. Scientific timeliness is beyond dispute because the majority of professionals in materials science are trying to solve the problem of behavior of the materials in expanded conditions of operation. Reviewed are the peculiarities of additional modules used for measuring hardness at alternating temperature conditions and indicated the advantages and limits of the considered configurations. A special effort is made to comparison of measurement systems where uniform temperature is maintained both in a sample and instrument with the devices where a sample is heated only. Introduced are the examples of a wide range of materials studied in various temperature ranges. Besides, the temperature dependence of aluminium matrix composite materials hardness in the range from 20 to 350 °C has been presented.
А.S.Useinov*, Cand. of Sci. (Physics and Mathematics), First Deputy Director of FSBI TISNCM, (ORCID: 0000-0002-9937-0954), Troitsk, Russia, K.S.Kravchuk*, Cand. of Sci. (Physics and Mathematics), Researcher, Troitsk, Russia, Ye.V.Gladkih*, Junior Researcher, Troitsk, Russia, S.V.Prokudin*, Junior Researcher, Troitsk, Russia
DOI: 10.22184/1993-8578.2021.14.2.108.116
Получено: 29.03.2021 г.
INTRODUCTION
Nowadays, instrumental nanoindentation is one of the most popular nondestructive methods to determine mechanical properties of any materials. The great success of this method can be explained by ease of use in comparison with usual tension and compression tests which require thoroughly treated samples and large quantity of the materials to be tested [1]. One of the reasons of popularity of nanohardness testers is the possibility to automatically collect and analyse data. After installing a sample and choosing the test software the user will obtain statistically processed data collected from a large area in a definitely short period of time.
It is well-known that mechanical properties of many materials are strongly dependent on temperature. Therefore, the coatings and bulky materials properties for high-temperature applications should be studied at the temperatures most closely approximated to the operating conditions.
It makes nanoindentation at controlled temperature to be a relevant method for industrial applications because of the explicit form to demonstrate behavior of materials at operating temperatures and conditions. From the scientific point of view, nanoindentation at controlled temperature is interesting because a small quantity of materials allows of choosing microstructural formations of interest in the material studied by this method with higher accuracy. It allows of studying kinetic aspects of physics of the materials by a new method and in the materials wherein the use of conventional methods would be impossible.
From technical viewpoint, the high-temperature nanoindetation has developed especially in last two decades. The essential progress is in both the materials used for making heater elements and casings of heating devices and in the indentor materials, depending on the specific working medium. However, the main problem of measurements at high or low temperatures is temperature gradients within devices or in sample-indenter contact area that lead to temperature drifts which are significantly distorting the results and make the quantitative measurements impossible.
To reduce the temperature drift, use is made of the materials characterised by a small or almost zero thermal expansion coefficient, also, the measurement system is configured so that the relative thermal expansions of the construction compensate each other while preserving the indentor contact area with th sample in the zero displacement zone.
Temperature differences in a contact area can be minimized by special design of a heater when a sample and an indenter have the same temperature during the indenting process. This problem is solved in the various way by different manufacturers (Fig.1). One of the solutions is a synchronous heating of the indenter and a sample by independent electrical (Fig.1a) and laser (Fig.1b) heaters. The second way is to create a heater systems so as to create a uniformly heated volume where a sample and indenter are located (Fig.1c).
Both ways allow of making a system with minimum temperature drifts and instrumental noise. Serial instruments equipped with diamond indenters have sample heating temperature range up to 500 °C. However, a study of iron-contained compositions has a limit connected with a danger of indenter destruction because of carbide formation at the interaction of carbon and iron.
Variants of temperature measurement methods using "NanoScan"
Domestic nanohardness testers "NanoScan" are serial devices intended for measurements of the physical and mechanical properties of materials in linear micro- and nanometer length scale (Fig.2). "NanoScan" serial devices have a module concept. The basic module of "NanoScan" series measures mechanical properties by instrumental indentation method according to recommendations of ISO 14577 and GOST Р 8.748-2011 standards in the wide range of loads [2-4].
A device may have one, two or three measuring modules depending on dimensions of chosen platform. Moreover, available are the additional modules such as optical microscope, optical confocal profilometer, scanning probe microscope module or Vickers micro-hardness tester. A model of "NanoScan-4D" nanohardness tester is listed in the National Register of Measuring Equipment (see the Certificate of Attendance of Measuring Equipment RU.C.28.002.A No.
63952). A scanning probe microscope – nanohardness tester is listed in the National Register of Measuring Equipment (see the Pattern Approval Certificate Measuring Instruments RU.C.27.004.A No. 36630/1).
Depending on "NanoScan-4D" model, it may be equipped with additional modules such as lateral loading detector, specimen stage with heating of samples, etc.
"NanoScan-4D" series makes use of several approaches to measure the mechanical properties at various temperatures.
Usage of a climate chamber
A compact "NanoScan-4D" model can be installed as a unit into the "heat-cold-moisture" climate chamber. This model is highly reliable and can be operated in a temperature range from –60 to +100 °C. A control workstation and an electronic control unit are placed outside on the working desk, and a carrying frame with an indenter module is placed inside the chamber.
The advantage of that approach is a possibility to measure samples of a significantly larger scale (up to 100 × 100 × 50 mm). As an example, Fig.4 indicates testing data of rather worn out automobile tires. The real and supposed parts of a complex elastic module and tangent of mechanical losses in the frequency range from 0.1 to 50 Hz [5, 6] have been measured in the temperature range from –60 to +60 °C.
Built-in specimen stage with Peltier elements
A principle diagram of such design is indicated in Fig.5 [7]. The advantage of Peltier elements usage is a low response to heating and cooling processes, and, accordingly, a fast stabilisation of the operation mode. The disadvantage of this design is a small size of a study sample and relatively narrow temperature range (from 2 to 60°C). This module can be used to study polymer materials, for example, polycarbonate, ultra-high-molecular-weight polyethylene (UHMWPE) and there analogies.
High-temperature specimen stage
One more solution to enlarge operation possibilities of "NanoScan-4D" serial devices is a built-in high-temperature specimen stage to heat samples (Fig.6). This device is intended to operate with the relatively small samples (no more than 15 × 15 × 5 mm in size) in the temperature range from 20 to +450 °C. The device has the upper and lower heaters that provide the uniform heating up of the working chamber volume where the study sample and indenter are placed.
A special ceramic heater, thermal shield, double-sided water cooling system and precision thermal controlled system make it possible to minimize temperature drifts during the measurements. Figure 7 shows the temperature drift diagram measured at melted quartz sample indenting loaded with 50 mN at a temperature of 400 °C. After thermal stabilization of a specimen stage, a thermal drift during a contact between a sample and the indenter does not exceed 0.06 nm/sec at constant loading of the indenter with an accuracy of dF=1 µN.
As an example how this module is used, it is possible to demonstrate a dependence of the hardness of nanostructured aluminium matrix composite materials versus temperature: test No.1 – along the extrusion axis, test No.2 – in the perpendicular direction to the extrusion axis [8]. Measurements of hardness were performed by the instrumental indentation method according to recommendations of GOST Р 8.748-2011 (ISO 14577-1:2002).
CONCLUSIONS
This paper presents a review of the technical solutions which can be applied for measuring physical and mechanical properties of the materials by the instrumental indentation method in temperature range from -60 to +450 °C using "NanoScan-4D" series nanohardness instruments. There is a wide choice of the instrument modules depending on specific tasks to be accomplished (see Table 1).
ACKNOWLEDGEMENTS
The authors thank to Mr Reshetov V.N. for the active participation in discussion of a design and methods to carrying up the high-temperature measurements using "NanoScan" serial devices. The research was carried out with the financial support of the Ministry of Education and Science of Russian Federation in a frame of National Assignment for FSBI TISNCM. ■
Declaration of Competing Interest. The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper.
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