Fatigue Testing on Metals Under Different Temperature Influences
The Bulgarian Academy of Sciences is the leading scientific center of expertise in Bulgaria and has been around for more than 150 years. The center conducts research and training and is made up of 42 autonomous scientific units with a total of over 3000 scientists.
The test system in use
The Institute of Metallurgy, Equipment and Technologies with the Center for Hydro- and Aerodynamics and the Institute of Mechanics - partners from Bulgarian Academy of Sciences in the project to establish a National Center for Excellence in Mechatronics and Clean Technologies, purchased a flexibly designed machine configuration with a high-temperature furnace and temperature chamber in order to perform a wide variety of tests from various faculties (mechanical engineering, materials science, etc.). The optimal testing system for their needs was an HА250 servo-hydraulic testing machine. The laboratory team focuses on fatigue tests (tensile, compression and flexure tests) of flat and round specimens, as well as fracture mechanics tests on CT specimens. The generated measurement data is essential for research and is used for future publications. In addition, the machine will be used for industry contract testing.
The temperature chamber is attached to rails, which allows it to be moved into the test area as needed, to run tests in the range of -80 to +250 °C. Specimens are easily gripped via hydraulic body over wedge grips. For flexible conversion purposes, flexure and CT specimen grips can be directly adapted onto the hydraulic grips.
High-temperature load strings can be mounted in the test area to perform low cycle fatigue tests according to ASTM E606 on threaded-end specimens. In order to do this, the temperature chamber is moved to the rear, and the high-temperature furnace is swiveled in. The high-temperature furnace can reach temperatures up to approximately 1000 °C. This test is a slow and strain-controlled test that can run with triangular, trapezoidal or sinusoidal signal, and uses a high-temperature extensometer with ceramic sensors.
