Facilities
The Rock and Mineral Physics Lab at the University of Minnesota houses a range of equipment for performing rock deformation experiments at extreme conditions. Our primary apparatus are two gas-medium Paterson apparatus for high-temperature and high-pressure experiments. We also have equipment for high-temperature, room-pressure experiments and a variety of equipment for preparing samples for experiments and subsequent microstructural characterization.
In 2017, the Rock and Mineral Physics Lab relocated from Kohltoff Hall to join the School of Earth and Environmental Science as part of a major renovation of Tate Hall. Look through the media below to tour our equipment and new lab space.
Our group members also use equipment external to the Rock and Mineral Physics Lab, including electron microscopes at the Characterization Facility, Fourier-transform infrared spectroscopy, and the Deformation-DIA at Argonne National Lab.
Paterson Apparatus (PI-10)
PI-10 was the second Paterson apparatus to be installed in the Rock and Mineral Physics Lab and has been in operation since 2000. Similar to PI-3, confining pressures up to 300 MPa are generated by Argon gas. Temperatures up to 1250°C are generated by a furnace internal to the pressure vessel. A major benefit of this particular furnace design is the relatively small temperature gradient across the sample (~1°C over the entire sample length). A compensated actuator allows for axial compression and tension of samples that are on the order of 1 to 3 cm in length.
There are two primary features of PI-10 not available on PI-3. First, PI-10 is fitted with a torsion actuator to twist samples by applying a torque to the loading column. This capability allows very high shear strains to be achieved for investigating microstructural evolution. Torsion can also be combined with compression or extension to generate a wide range of stress states and deformation geometries. Second, PI-10 is fitted with a pore-pressure system, which allows the pore pressure within the sample to be monitored and modified.
Paterson Apparatus (PI-3)
PI-3 was one of the first three commercially made Paterson apparatus and has been the workhorse of our lab since it was first installed in the early 90's. Confining pressures up to 300 MPa are generated by Argon gas. Temperatures up to 1250°C are generated by a furnace internal to the pressure vessel. A major benefit of this particular furnace design is the relatively small temperature gradient across the sample (~1°C over the entire sample length). A compensated actuator allows for axial compression and extension of samples that are on the order of 1 to 3 cm in length.
Gas-Mixing Furnaces
The Rock and Mineral Physics Lab houses several gas-mixing furnaces for static experiments at high temperature and low pressure. Samples can be heated in a chemical environment set by flowing a controlled gas mixture over the sample or by drawing a vacuum on the furnace tube. These furnaces are used for a variety of annealing, sintering, and diffusion experiments, as well material preparation for sample synthesis.
Uniaxial Creep Rigs
The 1-atm creep rig is designed for constant load experiments on samples at high temperatures (up to 1500°C) in a controlled chemical environment. The chemical environment is set by flowing a controlled gas mixture over the sample. Constant loads are applied by dead loading a cantilevered weight pan. An axial extensometer allows precise measurement sample displacement, avoiding effects from apparatus compliance and thermal expansion. Samples can be deformed both in compression and in tension.
Sample Preparation and Characterization
Sample preparation before and after experiments is conducted within the Rock and Mineral Physics Lab. We house a range of machining, cutting, grinding, and polishing equipment used to prepare samples for deformation experiments and to prepare samples for subsequent characterization.
The Rock and Mineral Physics Lab also houses a range of visible light microscopes, including reflected light, transmitted light, and binocular stereoscopes. We generate publication quality images and analysis with a Zeiss AxioImager, which includes automated mosaic imaging of samples in reflected light with a three-axis motorized stage.