The linear thermal expansion coefficient of Inconel 617 alloy

The experimental results of a study of the thermal expansion of Inconel 617 alloy in the temperature range of 293.15-1460 K are presented. An anomalous change in the thermal expansion coefficient at high temperatures was detected. The initial data are obtained with an error within 3%. The approximation equations and the table of reference values for the temperature dependence of the volumetric properties are obtained.

Investigation of BaSO4-KPO3-Na2B4O7 Low-Melting Glass System as a Basis for Synthesis of a Glass-Solder Material

The possibility of using the compositions of BaSO4-KPO3-Na2B4O7 system as a glass-solder (frit) material was shown. A glass formation region has been established in BaSO4-KPO3-Na2B4O7 system which is located in the borate-phosphate part of the concentration triangle and occupies ~41% of the triangle area. The concentration dependences of linear thermal expansion coefficient (TCLE), the softening temperature and the glass transition temperature was determined and discussed. It is established that the glass formation region, the concentration dependences of TCLE and technological temperatures values are significantly closer to those for CaSO4-KPO3-Na2B4O7 system than for MgSO4-KPO3-Na2B4O7 system. That may point out at the similar effect barium sulphate and calcium sulphate doping in the sulphate-phosphate-borate systems.

Evaluation and analysis of the uncertainty measurement linear thermal expansion coefficient of ceramic brick

With the continuous and high-speed growth of economy, people's requirements on product quality are increasing year by year, including ceramic brick products, which, as a typical building materials product, are widely used in all kinds of buildings of different sizes. Quality of brick of pottery and porcelain products mainly in the form of through the examination and evaluation. The uncertainty of measurement as an important part of the test results, is an important parameter characterization of the reliability of the measurement result. Therefore, this paper, the source of uncertainty in linear thermal expansion coefficient measurement of ceramic brick is analyzed, using the measurement results and related data, and concludes that for the linear thermal expansion coefficient average of 0.016%. when the report 2 sample average, the expanded uncertainty U (A) = 1.48%, contains the factor k = 2.

Thermal Expansion of Triaxially Stressed Mudstone at Elevated Temperatures up to 400°C

In order to study the thermal deformation of the rock that surrounds underground engineering projects with elevated temperatures (e.g., underground coal gasification, coal in situ pyrolysis, in situ oil and gas extraction from oil shale, geothermal energy extraction from rock, among others), a servocontrolled machine (model IMT-HTP 100F) was used to examine the thermal expansion of triaxially stressed mudstone at temperature up to 400°C. Two distinct stages of thermal expansion were found at temperatures up to 400°C: very small thermal expansion below 50°C, followed by almost constant thermal expansion at 50–400°C. This linear thermal expansion coefficient of triaxially stressed mudstone did not increase in the range 50–400°C. The effect of the applied triaxial stress was on both close cracks and impeded grain expansion and the swelling of the rock. Mudstone had a larger linear thermal expansion coefficient than either sandstone or limestone, in that order. The potential energy theory was used to explain the intrinsic variation of thermal expansion of the different rock types.

Thermal Expansion of Composite System Epoxy Resin/Recycled Carbon Fibers

This experimental study deals with the problematics of thermal expansion α [10-6/K] of the composite systems based on recycled carbon fibres reinforced epoxy resin. The epoxy resin CHS – EPOXY 520 (EPOXY 15), cured with the hardener P11 (Districhem, s.r.o.), was chosen as a sample matrix. Recycled carbon fibres with a diameter of 7 μm and a length of 100 μm (Easy Composites Ltd.) were the filler. In the experiment, samples with the fulfilment of 10, 20, 40, 60, 80, 90 and 100 phr were prepared. The samples were being poured into silicone molds, cured at an overpressure of 0.7 MPa and a temperature of 23 ± 2 °C for 24 hours. A thermomechanical analyzer was used to determine the thermal expansion of composite systems. The addition of recycled carbon fibers to epoxy resin can reduce the coefficient of linear thermal expansion at 20°C in half, from the original α = 45 to 55 × 10-6/K for non-filled epoxy resin to α = 25 to 27 × 10-6/K for filled epoxy resin. Optimal filling is at the level of 40 phr, with higher filling there is no further reduction of the linear thermal expansion coefficient.