Alloy Solidification and Physical Metallurgy Laboratory
Gilman Hall 3304, 3308, 3312, 3284
R. E. Napolitano, Professor, Department of Materials Science and Engineering, Iowa State University
Principal Research Facilities in the ASPML
Melting, casting, and heat-treating – The ASPML includes a Blue-M top-loading electric melting furnace, capable of temperatures up to 1100°C for small alloy charges (e.g. 2 kg aluminum). Various crucibles and steel and copper molds are available.
Directional solidification – The ASPML includes a translating gradient-stage directional solidification system, generally capable of temperatures up to 1100°C and thermal gradients between 5 and 25°C/mm. The unit includes a resistance furnace with an internal booster heater, a water-cooled liquid metal (Ga-In-Sn) cooling chamber, a programmable high-resolution stepper-motor-controlled translation system (capable of 0.0001 to 500 mm/s translation), an atmosphere (vacuum/inert-gas) control system, and thermocouple-based instrumentation for temperature/gradient measurement.
Transparent material solidification– The ASPML includes facilities for in situ investigation of transparent materials (e.g. metallic analogs) under conditions of directional growth and uniform cooling. The lab includes facilities for purification of these by distillation and zone refining.
Arc melting/welding processing– The SPML includes a Miller-700 water-cooled gas-tungsten arc-welding (GTAW) unit with cold-crucible copper hearth accessories for melting and alloying small charges (up to ~200 g).
Electromagnetic levitation melting– Vacuum and inert gas EML melting capabilities allow container-less pressing of metallic alloys (and other conductive materials).
Heat treatment– The ASPML includes several high- and low-temperature programmable box furnaces for heat treating, with a fume hood for oil-quenching.
Microstructure analysis– The ASPML includes metallographic specimen preparation facilities for fine sectioning, fixed abrasive grinding, slurry-based polishing, and chemical etching. Metallographic analysis equipment includes an Olympus GX51 inverted stage optical microscope with an Olympus DP27 imaging system and Olympus Stream 2.3 software, along with several other upright stage and stereo-zoom microscopes.
Mechanical testing– Mechanical testing capabilities within the SPML include a Shimadzu AGX-Plus 50kN uniaxial load frame and a Shimadzu HMV-2 microhardness tester.
Metals fabrication– In addition to casting and welding facilities, machine shop facilities are maintained within the ASPML for general purpose tooling and fabrication. These include a horizontal band saw, a vertical drill press, lathe, and compound milling machine.
Additional Critical Facilities
In addition to the equipment within the ASPML, research activities rely on shared facilities at Iowa State University. Some of the critical shared instrument capabilities are described briefly below.
- FEI Inspect Scanning Electron Microscope – The FEI Inspect S is a field-emission SEM with secondary and backscattered electron detectors. Access is managed by the MSE Department Laboratory Coordinator at Iowa State University.
- FEI Teneo Scanning Electron Micoscope – The FEI Teneo is a field-emission SEM, equipped with Oxford EDS and EBSD capabilities for combined elemental and phase mapping and texture determination. Access is managed by the Sensitive Instruments Facility at the Iowa State University Applied Science Complex.
- FEI Titan Transmission Electron Microscope – The FEI Titan Themis 300 Cubed is an aberration-corrected (scanning) transmission electron microscope with monochromator, Super-X EDX detector, GIF quantum ER system and a Lorentz lens with biprism.This system provides atomic-level imaging capability (to ~0.07 nm resolution). Techniques include energy dispersive X-ray spectroscopy (EDS), electron energy loss spectroscopy (EELS), tomography, electron holography and Lorentz microscopy. (S)TEM hot stage operation can also provide in situobservation of structural and chemical aspects of transformations at the atomic level. Access is managed by the Sensitive Instruments Facility at the Iowa State University Applied Science Complex.
- Robo-Met.3D Three-dimensional analysis system – The Robo-Met.3D is a self-contained fully automated serial sectioning/polishing system for three-dimensional microstructural analysis. The instrument can be programmed to incrementally remove a predefined amount of material by executing a user-set polishing routine, followed by etching (for a pre-defined time), neutralizing, drying and transfer to an inverted optical microscope with a motorized stage. The process is carried out repetitively in a fully automated manner, compiling many 2D images, which are aligned and processed, using an integrated software package to render the structure in full 3D. Access is managed by the MSE Department Laboratory Coordinator at Iowa State University.
- TA Instruments Q2000 Differential Scanning Calorimeter – The Q2000 DSC is a research-grade thermal analysis instrument with excellent baseline flatness, precision, sensitivity, and resolution. Heating rates up to 200°C/min are attainable, and liquid nitrogen cooling provides an operating temperature range of -180 to 725° The instrument is housed in Hoover Hall, and access is managed through the MSE Department Laboratory Coordinator. Access is managed by the MSE Department Laboratory Coordinator at Iowa State University.
- Thermo Fischer FEI Helios NanoLab G3 UC – The Helios dual-beam focused-ion-beam (FIB) and electron-beam system is capable of performing analysis in normal scanning electron microscope mode as well as focused ion microscope mode. The FIB is capable of milling operations for preparing a pristine for other characterization techniques such as transmission electron microscopy (TEM). Access is managed by the Sensitive Instruments Facility at the Iowa State University Applied Science Complex.