Method for determining temperature of full polymorphous transformation of heat-resistant two-phase titanium alloys of (alpha+beta)-martensitic class
SUBSTANCE: method for determining temperature of full polymorphous transformation of heat-resistant two-phase titanium allows of (α+β)-martensitic class is proposed, which involves preliminary preparation of a specimen by means of multistage heat treatment of the latter, which is performed immediately in a differential thermal analysis (DTA) instrument in atmosphere of cleaned argon and its investigation using DTA method. Heating of the alloy specimen to single-phase β-area, supercooling below temperatures of active diffusional decay of β solid solution, short-term exposure and repeated heating to the single-phase area is performed. Fixation of dependence of a DTA signal on temperature and calculation of values of derivative of DTA signal on temperature is performed, and temperature of completion of full polymorphous transformation is determined as per maximum on the curve of the first derivative of DTA signal at repeated high-temperature heatinge.
EFFECT: improving determination accuracy of temperature of full polymorphous transformation in heat-resistant two-phase titanium alloys.
The invention relates to the field of research of processes of polymorphic transformations in metals and solid-phase metal alloys and can be used, for example, in the technical control of metallurgical plants producing titanium and alloys based on it.
The temperature of polymorphic transformation (temperature end of the polymorphic transformation temperature TPP) is the temperature above which the alloy structure is absent α-phase and the alloy consists of stable β-solid solution.
Modes of thermomechanical processing, namely, the heating temperature and deformation processing, industrial grades of alloys based on titanium have
where Tn- temperature/strain specific melting alloy;
TPPthe temperature of complete melting polymorphic transformation, changing within the brand alloy in a certain range;
N is the Offset from TPP. N does not depend on the chemical composition of the melt and within the brand alloy is constant.
Thus, to select a specific temperature heating/deformation of the alloy necessary information about TPPused for melting. In addition, in most cases, the overheating of the alloy above TPPthe final stages of processing is unacceptable as it results in the it to a significant growth of the original β-grains and deterioration of mechanical properties of the semi-finished product.
There is a method of determining the temperature of polymorphic transformation (TPP) titanium alloys by the method of trial sakaluk . The essence of this method consists in fixing the structure of the alloy after quenching with heating at successively higher temperatures in the region of the α+β→β transition.
This method is very time-consuming, requires making a large number of special designs, sophisticated laboratory equipment and, in addition, are not known with great precision, and high performance.
There is also known a method of determining the temperature TPPin two-phase titanium alloys, including heat samples for hardening to a predetermined temperature, determining their microstructure and identifying dependencies between the heating temperature for quenching and number of primary α-phase .
Using this method, you can determine the temperature TPPby quenching and study of the microstructure of a single sample, but the main disadvantages are that it is still very time consuming and not very accurate and high performance.
In addition, well-known simplified metallographic method for the determination of TPPbased on deep etching of the samples after quenching with different temperatures in the interval of occurrence of polymorphic transformation. At this surface the samples, hardened from the α+β region becomes opaque and after quenching from the β-region remains shiny .
The main disadvantage of this method is its applicability only to alloys (α+β)-class, and relatively low precision.
Sometimes applied the settlement method of determining TPP according to chemical analysis. For this purpose experimental dependences of TPPalloy on the concentration of alloying elements.
Also known a more General approach for the analytical determination of TPPmelting based on the concentration of alloying elements for industrial titanium alloys of any brand .
The disadvantages of calculation methods for the determination of TPPis the use of experimental correlation dependences, as well as the absence of common regression coefficients for all of the used alloying elements and impurities.
In addition, there is a method of determining the temperature TPPtwo-phase titanium alloys by fixing the temperature of the free deflection, which corresponds to TPPfixed sample under continuous heating contact method .
There is also known a method of determining the end temperature of the α+β→β transformation using the method of acoustic emission . The essence IU the ode is to measure the radiated acoustic emission and the analysis of its activity during continuous heating of the sample. The fixing temperature TPPproduced by abrupt reduction in the activity of acoustic emission.
Lack of data is the need to use equipment that is not produced commercially, which seriously reduces the possibility of using these methods in industry, in particular in the technical control of metallurgical industries, since it is difficult to ensure reproducibility and repeatability of results.
Also known application of the dilatometric method for determining the temperature of the end of the α+γ→γ transformation (AC3in steels, which is the analogue of temperature TPPin alloys based on titanium [6, 7].
The use of the dilatometric method for determining the temperature TPPtwo-phase titanium alloys is complicated by the low volume effect in the course of the α+β→β transformation.
Also known applications of the methods of differential thermal analysis and differential scanning calorimetry (DSC) to determine the end temperature of polymorphic transformation in alloys based on titanium [8, 9].
It is known [8...10] noted that when using thermal analysis techniques such as DTA and DSC, recorded in experiments curves continuous heating is strongly influenced by the original structure of the research is imago sample, in particular, the morphology of the α-phase in the alloy structure. In particular, if the structure of a large primary precipitates of α-solid solution instrumentally recorded temperature end of the α+β→β transformation is higher than the equilibrium TPPdetermined by metallographic techniques. Accordingly, for each melt of the alloy is necessary to use different heating rates in order instrumentally recorded temperature was correlated with temperature TPPdetermined by metallographic techniques trial sakaluk.
The technical task of the invention is to improve the accuracy and productivity of determining the temperature of polymorphic transformation of two-phase titanium alloys by the method of differential thermal analysis.
To solve this technical problem, a method for determining the temperature of complete polymorphous transformation of two-phase heat-resistant titanium alloys (α+β)-martensitic class, including preliminary training patterns of the alloy and its study by the method of differential thermal analysis (DTA) under continuous heating of the sample alloy and wherein the preliminary preparation of the structure is realized by means of multi-stage heat treatment of the sample that Provo is drawn directly into the device DTA in the atmosphere of purified argon, moreover, preliminary multistage thermal treatment includes rapid heating in single-phase β-region, subcooling temperatures below the active diffusion decay β-solid solution, short-term exposure and re-heating in single-phase region with a predetermined controlled speed, during which spend fixation according to the DTA-signal from the temperature and the calculation of values of the derivative DTA signal, and the temperature of the end of the full polymorphic transformation is determined by the maximum on the curve of the first derivative DTA signal at repeated high-temperature heating.
The invention is illustrated graphic materials, in which figure 1 shows a diagram of the temperature profile DTA experiments, figure 2 - microstructure of samples alloy VT3-1, quenched from different temperatures, figure 3, 4 - areas DTA-curves of repeated continuous high-temperature heating of the samples of the alloy VT3-1 and VTM and calculated according to the partial derivatives DTA signal from the temperature.
The order of operations in the specified way of determining the full temperature of polymorphic transformation alloy VT3-1 is as follows:
1. The sample melting alloy is placed into the measuring cell of the device DTA.
2. The heat chamber of the measuring device is filled with an inert atmosphere, the quality of the solid fuel which is used argon technical purity additionally purified by the adsorption method, moreover, in a heat chamber of the device during the whole experiment must be supported gauge pressure (relative to atmospheric) controlled atmosphere.
3. The sample of the alloy is heated in a single-phase β-region with the maximum sold used by the device speed.
4. The sample directly after heating pereohlajdenia up to temperatures of 600...650°C (below the interval of the high-temperature decomposition of β-solid solution most heat-resistant two-phase α+β alloys martensitic class) with the most-sold rate on your device differential thermal analysis.
5. The sample is aged at a temperature of hypothermia in a few minutes to equalize the temperature in his section.
6. After isothermal aging re-heating of the sample alloy in single-phase β-region with speed, selectable individually for each grade of alloy.
7. After the experiment is calculated partial derivate of the first order numerical method the original DTA-signal time.
8. The temperature of the end of polymorphic transformation after processing according to the specified mode is determined by the maximum on the curve private derivative of the first order.
This technical solution is confirmed investigated the s of the bottoms of two-phase titanium alloys martensitic class VTM and VT3-1.
Metallographic studies have established that the temperature TPPthe investigated melts (by the method of trial sakaluk) equal 973°C and 980°C for alloy VT3-1 and VTM respectively (figure 1). In the proposed method: TPPalloy VT3-1 is 977°C and 982°C for alloy VTM.
A sample of the alloy dimensions 3×3×3 mm (D×V×W) is placed in the measuring cell device DTA NETZSCH STA 449C Jupiter" (maximum speed of heating and cooling to 50°/min) and processed according to the mode, the circuit of which is shown in figure 1. When processing are recorded according to the DTA-signal from the temperature at various speeds and re-heating in single-phase β-region (3, 4).
After the experiment is performed numerical calculation of the partial derivate of the first order initial DTA-signal time and the build dependencies of the values derived from the current temperature.
The course polymorphic α+β→β transformation during heating takes place with absorption of energy (i.e., the polymorphic transformation process is endothermic) , therefore under continuous heating of the sample alloy on the DTA curve in the temperature range of polymorphic transformation is fixed endothermic effect. Thus, the dependences of the private values of the derivative DTA temperature in the temperature range downward in the Twi endothermic effect observed local maximum.
Joint analysis of the obtained dependences of the derivative DTA signal from the temperature shows that for alloy VT3-1, the rate of repeated high-temperature heating 20°/min provides the ability to define TPPwith an accuracy not lower than the accuracy of the method of trial sakaluk - 3. For alloy VTM - speed re-heating, provide the calculation of the TPPthe proposed method is 50°/min
Samples of alloy VT3-1 and VTM was placed in the measuring cell device simultaneous thermal analysis NETZSCH STA 449C Jupiter" and processed according to the mode, the circuit of which is shown in figure 1. When the treatment was carried out recording dependencies DTA signal from the temperature at various speeds and re-heating in single-phase β-region. After the experiment was conducted numerical calculation of the partial derivatives of the first order initial DTA-signal time and built according to the values derived from the current temperature (figure 3, 4) for all investigated heating rates. Through joint analysis of the obtained dependences of the derivative DTA signal from the temperature were selected speed reheating samples for the determination of TPPthe proposed method is 20°/min for alloy VT3-1, 50°/min for alloy VTM.
The proposed method of determining the temperature of polymorphic transformation in dujfasp the x titanium alloys can improve the accuracy of determining the end temperature of polymorphic transformation heat-resistant two-phase titanium alloys (α+β)-martensitic class.
Sources of information
1. Metallography of titanium alloys. Edited Anoshkina NF, Bochvar GA, Livanov, VA and other M, metallurgy, 1980, p.36.
2. Copyright certificate №394709, G01N 25/02, 1973, No. 34, p.142.
3. B.A. Kolachev, SHE Egorova, S. B. Belov. The relation of the temperature of the α+β→β transition of industrial titanium alloys and their chemical composition / Metallography and heat treatment of metals. 2008. No. 8 (638), p.10...14.
4. RF patent 2248539, G01K 9/00, G01N 25/02.
5. The invention application EN 2010134056, 13.08.2010.
6. Ryzhkov M.A., A.A. Popov, Methodological issues of building thermokinetic diagrams of transformation of undercooled austenite in low-alloy steels / metal Science and heat treatment of metals. No. 12 (666). 2010. p.37...41.
7. ASTM A 1033-04. Standard Practice for Quantitative Measurement and Reporting of Hypereutectoid Carbon and Low-Alloy Steel Phase Transformations. ASTM, 2004. 14 p.
8. TIAN Fei, ZENG Wei-dong, MA Xiong, SUN Yu, ZHOU Yi-gang. Measurement of beta transus temperature of BT25 titanium alloy by physical analysis and metal lographic observation methods / Transactions of Materials and Heat Treatment. 2011. Issue 5.
9. Carton M., Jacques, P., Clement N., Lecomte-Beckers J. Study of Transformations and Microstructural Modifications in Ti-LCB and Ti-555 Alloys Using Differential Scanning Calorimetry / Ti-2007 Science and Technology. 2007. pp.491...494.
10. A.I of Gadaev, A.G. Illarionov, A.A. Popov, M.A. Ryzhkov, E.V. Kolosova, M.A. Popov, PS Altman, NN. Bondaruk. Using the method of thermal analysis to determine the full temperature of polymorphic transformation of two-phase titanium alloy and the VA / Scientific and technical journal "Titan". 2010. No. 1. P.24-30.
11. Handbook of thermal analysis and calorimetry: Principles and Practice / Michael E. Brown. London: Chapman and Hall, V.2. 1998. - 725 p.
The method of determining the temperature of complete polymorphic transformation heat-resistant two-phase titanium alloys (α+β)-martensitic class, including preliminary training patterns of the alloy and its study by the method of differential thermal analysis (DTA) under continuous heating of the sample alloy, are cleansed by the fact that the preliminary preparation of the structure is realized by means of multi-stage heat treatment of the sample, which is carried out directly in the device DTA in the atmosphere of purified argon, and the preliminary multi-stage heat treatment includes rapid heating in single-phase β-region, subcooling temperatures below the active diffusion of the decay d-solid solution, short-term exposure and re-heating in single-phase region with predetermined controlled speed, which are fixed according to the DTA-signal from temperature and determine the value of the derivative DTA signal, and the temperature of the end of the full polymorphic transformation is determined by the maximum on the curve of the first derivative DTA signal at repeated high-temperature heating.
SUBSTANCE: oil sample is heated with one-time temperature control, the sample is continuously cooled with simultaneous measurement of shear stress. Chilling point is determined from temperature corresponding to the first abrupt increase in shear stress, and bulk freezing point is determined from temperature corresponding to the second abrupt increase in shear stress. The sample is heated to temperature of 60-80°C. Heating and temperature control of the sample is carried out while revolving the viscometer cylinder and the sample is cooled at a rate of 1-2°C per minute.
EFFECT: high information value and reliability of the analysis method.
FIELD: test engineering.
SUBSTANCE: body under study is brought into thermal contact with the reference body in the plane in which the local circular heater is located. At regular intervals of time the difference of values of the temperature between the heater and the point of plane of contact of the body under study and reference body is measured. The tests end up in excess of the specified value by the controlled dynamic parameter. The dependence of the current value of thermal activity on the temperature of the body under study is made. The structural transitions in polymeric materials are determined by the presence of peaks on dependence of the current value of the thermal activity on the temperature of the body under study.
EFFECT: improved method.
SUBSTANCE: method of determining volatility and heat of vaporisation of a mixture of liquid substances from the rate of evaporation from a flat surface involves establishing a correlation relationship between volatility values, calculated using known reference data, for individual liquid substances selected as calibration liquids, and the rate of evaporation thereof, determined based on data from thermogravimetric analysis carried out in isothermic conditions when an equilibrium state is achieved. The rate of evaporation of the analysed mixture is determined and the volatility value is found from the correlation relationship. The heat of vaporisation of the mixture of liquid substances in the analysed temperature range is determined using the relationship between the found volatility values and temperature. The value of the heat of vaporisation is determined from the value of the slope of a linear graph, the abscissa of which is the value of the inverse absolute temperature and the ordinate is the logarithm of the product of the experimentally determined volatility value and the absolute temperature value.
EFFECT: high reliability and objectivity of estimating volatility of not only individual liquids, but also mixtures thereof at different temperatures, broader functional capabilities of the method of determining volatility.
2 cl, 6 dwg
SUBSTANCE: method involves separate temperature control of cylindrical samples which make up a eutectic system, one of which has the analysed composition and the other is homogeneous, for example, consists of a pure substance. The samples are brought into contact at analysis temperature which is higher than the eutectic point, and the position of imaging point of the analysed alloy relative the solidus curve is determined from the state of the liquid layer formed between the samples.
EFFECT: invention enables more accurate plotting of a solidus curve on a phase diagram.
3 dwg, 1 tbl, 1 ex
SUBSTANCE: method of determining thermo-oxidative stability of lubricating materials involves heating the lubricating material in the presence of air and mixing. Oxidised lubricating material is then collected. Oxidation process parameters are then photometered and determined using graphical curves. Two samples of the lubricating material of constant weight are tested separately with and without a catalyst. While heating, the two samples of lubricating material of constant weight are tested successively with and without a catalyst, stirred while periodically varying testing temperature from temperature at the onset of oxidation and maximum temperature. Temperature is the lowered from maximum temperature to temperature at the onset of oxidation over a constant period of time. After each testing temperature, with and without a catalyst, the samples are weighed, the weight of the evaporated sample and evaporation number are then determined as a ratio of the weight of the evaporated sample to the weight of the remaining sample. By photometering, the light flux absorption factor with and without catalyst is determined, the thermo-oxidative stability factor is determined as a sum of light flux absorption factor and evaporation number. Further, the influence coefficient of the catalyst KVK on oxidative processes is determined using the formula KVK=KK/K, where KK and K are thermo-oxidative stability factors of samples of the lubricating material with and without catalyst, respectively. A curve of the influence coefficient of the catalyst on the oxidative processes versus the testing time is then plotted, and thermo-oxidative stability of the lubricating materials is then determined from values of the influence coefficent of the catalyst on the curve. If KVK>1, thermo-oxidative stability is falling, and if KVK<1 thermo-oxidative stability is increasing.
EFFECT: high information content of the method of determining thermo-oxidative stability of oxidation and evaporation processes during periodic variation of the testing temperature.
3 dwg, 1 tbl
SUBSTANCE: proposed method consists in measuring activity of acoustic emission signals emitted by tested specimen in heating. Polymorphic transformation temperature is defined as temperature corresponding to the moment of stepwise decrease in aforesaid activity.
EFFECT: higher accuracy and efficiency.
FIELD: instrument making.
SUBSTANCE: device for determining thermal stability of substances consists of cylindrical casing filled with warmth-keeping material, in which there coaxially placed is temperature-controlled metal cylinder with cavities made along its perimetre for arrangement of tightened reaction shells each of which is connected to pressure measurement and recording system. At that, each reaction shell is equipped with flame arrester and pneumatic drive connecting the reaction shell volume to pneumatic protector and precision temperature-compensated bipolar "pressure-voltage" converter which in its turn through multi-channel analogue-to-digital converter one of the inputs of which is connected to output of "atmospheric pressure-voltage" converter, is connected to pressure display and recording system. At that, in each pneumatic drive the provision is made for the tap which is equipped with valve connected to vacuum pump with automatic valve at the inlet, inert gas source and in-series connected pneumatic resistance and valve.
EFFECT: invention allows shortening the time and measurement period, calibration intervals, improves reliability at reducing overall dimensions and electric power consumption.
2 cl, 1 dwg
FIELD: instrument making.
SUBSTANCE: to investigate heat transfer in process of fluid metals cooling, a heat pipe is used, in which a heater of a heating zone is equipped with a controller and is arranged outside the pipe heating area. The heat pipe cooling area is made with a filling nozzle and a thermocouple arranged in it, and with cooling air. The cooling medium flow controller and the thermocouple for measurement of medium temperature are connected into the system of automatic control of the model operation. The device model is made with the scale M1=2÷5, where M1=la/lM, la - size of as-built heat pipe, lM - model size.
EFFECT: possibility to model cooling process.
SUBSTANCE: proposed vibro viscosimetric transducer reduces instability of amplitude and frequency of probe mechanical vibrations in analysing constant-viscosity fluids. Proposed transducer comprises probe mechanical current position pickup. Besides, it comprises mechanical vibration system rigidly coupled via rod with measuring spherical probe provided with thermocouple thermometre, and arranged on rigid base supporting electric exciter of mechanical oscillations of vibration system. Note here that said base is located inside outer temperature-controlled pickup casing and isolated thereof. Note also that mechanical vibration system is made up of two high-Q-factor vibration circuits rigidly fitted on the base to vibrate thereon, mainly, collinearly and linearly at close or equal resonance frequencies. Note here that exciter is arranged to interact only with vibrator provided with rod with measuring probe. Besides, mechanical vibration system represents a tuning fork with parallel operating and compensating vibrators.
EFFECT: reduced instability of amplitude and frequency of probe mechanical vibrations in analysing constant-viscosity fluids.
6 cl, 6 dwg
SUBSTANCE: signal simulator used is in form of at least micro-weighing chemically pure substances inside sealed cavities of a thermoacoustic waveguide rod (TAWR) with acoustic emission (AE) and temperature sensors, where the mass of said substances is determined with maximum accuracy and said substances have reversible anhysteretic temperature and energy of phase transitions (PT) of the first type (crystallisation/melting, evaporation/condensation), from which, in each cycle for heating and (or) cooling a sample in contact with the TAWR, by receiving AE signals of said PT and by simultaneously measuring contact temperature of the TAWR with the sample at PT points, temperature measurement channels and AE (sensors-amplifiers-converters) as a whole are checked and calibrated from temperature and energy characteristics of the PT of the first type of built-in thermodynamic acoustic-emission (TDAE) standards, by changing amplification coefficients or (and) threshold of sensitivity of measurement channels, or (and) amplitude-frequency characteristics (AFC) of temperature, electric and acoustic signal converters or (and) corresponding corrections when converting digital data to physical parameters. Possibility of TDAE standardisation is provided, which enables metrological support for thermal and (or) acoustic-emission analysis installations through dynamic and static inspection of their temperature and acoustic measurement channels.
EFFECT: increased reliability and accuracy of determining temperature and energy characteristics, stages for destruction of materials.
4 cl, 4 dwg
FIELD: investigating or analyzing materials.
SUBSTANCE: thermograph comprises differential thermocouple and aluminum thermal unit provided with two symmetrically arranged cylindrical holes for crucible with specimen and standard. The crucibles are made of cylinders with caps provided with copper pipes for hot junctions of Chromel-cupel thermocouples. The wires of the thermocouples are housed in the two-channel ceramic rods. The thermoelectric heating of the unit is provided with the use of temperature-sensitive resistor made of nichrome wire. The unit is mounted in the steel sealed housing with a lid and provided with a device for locking it inside the housing during cooling and heating.
EFFECT: simplified design and enhanced accuracy of measuring.
FIELD: polymorph processes in metals and electro-conducting materials.
SUBSTANCE: method of measuring temperature of polymorph transformation is based upon heating for hardening till temperature providing free sag of rigidly tight sample. The temperature should correspond to α→β polymorph transformation.
EFFECT: improved precision of measurement.
FIELD: measurement technology.
SUBSTANCE: device has trier provided with holder and measuring probe provided with thermocouple placed inside the trier. Thermocouple is used which has time constant less than 1,5 sec. Volume of part of thermocouple submerged into salt melt relates to volume of cup of the trier as (5x10-3-10-2):1. Precise value of temperature can be achieved as well as high degree of reproducibility.
EFFECT: improved precision; prolonged service life of thermocouple.
9 cl, 4 dwg
FIELD: test equipment.
SUBSTANCE: metal probe of vibration viscosimeter is disposed inside metal dish in tested fluid to make it thermally isolated from outer space. Viscosimeter is excited with preset frequency and with preset force. Temperature of the dish is changed monotonously and continuously to follow specified rule at speed to exceed speed of establishing processes of change in temperature of tested liquid inside the dish. Temperature of the probe is measured within whole preset range of changes in temperature of the dish as well as amplitude and/or phase and/or frequency of oscillations of the probe. Density, viscosity, thermal conductivity, heat capacity and thermal diffusivity of tested fluid are measured depending on fluid's temperature from the relation of heat diffusivity of fluid and from the relation of viscosimeter's probe forced oscillations. The main feature of the device realizing the method has to be the metal probe of viscosimeter made in form of copper ball or silver ball disposed in fluid for thermal insulation onto rod made of thermo-insulating material. Measuring converter of probe's temperature is made in form of thermocouple and built inside probe. Second measuring converter of probe's temperature, also made in form of thermocouple, is placed onto bottom of metal dish thermally insulated from environment.
EFFECT: improved efficiency of test.
10 cl, 5 dwg
FIELD: inspection of quality of oil products.
SUBSTANCE: permanent-weight lubricant is subject to heating in thermo-stable glass cup at three temperatures at least, which temperatures exceed that one of beginning of oxidation and then it is subject to mixing by glass mixer at constant speed during 12 hours or less. Samples for photometry are selected in equal time intervals. Factor of absorption of light flux by oxidized oil Ability to evaporation is measured by weighing sample before and after test. Graphical dependences of theses parameters are built relatively temperature of testing. Thermal-oxidative stability of lubricant is determined by critical temperature of service ability, by temperature of beginning of oxidation and by temperature of beginning of oxidation.
EFFECT: improved efficiency of measurement.
FIELD: investigating or analyzing materials.
SUBSTANCE: method comprises heating specimens to be analyzed with a rate of 10 deg/min, using standard initial polymineral clays, selecting temperature intervals 20-200°C, 600-800°C, and 20-100° C from the thermo-analytic curves of the standards, determining the reference values in the intervals, determining mass losses, and choosing maximum values of the mass losses in the intervals for the calculation of the fraction ration of clays.
EFFECT: enhanced accuracy of measurements.
6 dwg, 1 tbl, 6 ex
FIELD: measurement technology.
SUBSTANCE: method involves carrying out experimental temperature measurements of cooling liquid avalanche dissociation on hot surface under static conditions, without liquid flow being arisen.
EFFECT: simplified cooling liquid quality control process; reduced tested substance quantity in samples under test; personnel safety in carrying out tests.
FIELD: measuring technique.
SUBSTANCE: method comprises testing two samples of the lubricant of the same mass, the first sample being tested without catalyzer and the second sample being tested in the presence of catalyzer, determining transparency coefficient by means of photometric measurements, plotting time dependences of the transparency coefficient, and determining oxidation stability of the lubricant from the equation presented.
EFFECT: enhanced precision.
3 dwg, 1 tbl
FIELD: measuring technique.
SUBSTANCE: while warming sample up, average value of square of voltage of thermal electrical; fluctuations is measured at terminals of measuring converter. Maximal value, which corresponds to glass transition temperature, is measured, at which temperature the value of dielectric permeability is found and value of hardness coefficient is calculated. Method can be used for measurement of equilibrium hardness coefficient of polymer chains for polymers in unit.
EFFECT: improved precision of measurement.
1 dwg, 6 tbl
SUBSTANCE: method provides usage of temperature detectors to transform electric signal, and identification of type of phase transition. Electric Signal from temperature detector is corrected for value of electric signal which is generated by phase transition of material. Correcting electric signal is achieved by means of additional probe.
EFFECT: improved precision of measurement.
4 cl, 9 dwg