Mechanical Testing
Mechanical testing can be performed on any of several different types of load frames and/or creep frames, in order to meet the requirements of a particular test. The load frame types include: MTS axial (Figure 1), closed-loop, servo hydraulic test systems with load capacities ranging from 20 to 110 KiP's; one ATM axial-torsional (Figure 2), closed-loop, screw-driven test system which can simultaneously or independently apply axial and torsional loads up to 20 KIP tension/compression and 10K in-lbs, respectively. All of the load frames are completely automated with data acquisition, reduction and control software written specifically for tests typically associated with constitutive parameter evaluation and damage mechanics. In addition, three axial load frames are specifically equipped with alignment fixtures and hydraulic collet grips to precisely align the load train for ceramic specimens, as well as compression testing.

The lab is also equipped with creep frames of the direct load or lever arm type construction with a load capacity of 10 KIP's. Two of the creep frames are equipped with three zone clamshell style furnaces, capable of reaching a maximum temperature of 2,000°F, and compatible ATS LVDT indicating extensometry. The third creep frame is outfitted with a precision movement gripping system, typically used for moire interferometry studies.

Elevated Temperature Research
For elevated temperature research, the laboratory is appropriately equipped with furnaces, extensometry and temperature sensing/control devices, to suit a variety of isothermal, as well as transient temperature testing requirements. Test temperatures ranging from room temperature to 2,800°F can be accomplished using one of several different heating methods. The various types include: a Research Inc. 4KW quad elliptical quartz lamp oven; an MTS three zone resistive heating clamshell furnace (Figure 3); an MTS single zone, molybdenum disilicide, rapid resistive heating furnace; and two MTS environmental chambers. The lab also has a variety of extensometry for low to moderate temperatures, as well as temperatures in excess of 2800°F. Where applicable, these include: MTS tension/compression axial (models 632.41 and 632.59) and diametral (model 632.60) extensometers with a 1 inch gage capacity and ceramic and/or quartz extension rods; an MTS biaxial extensometer (model 632.85); and an assortment of MTS axial clip gages (models 632.11, 632.12, and 632.25) with gage capacities of 0.5 through 1 inch. Dual setpoint digital temperature controllers, with autotune PID control, can be used in conjunction with either an optical pyrometer or thermocouples in order to precisely meet the test temperature requirements. In addition, up to 32 temperature measurements, from intrinsically or contact mounted thermocouples, can be digitized via the low level data acquisition system and simply recorded or used to control other events in the test environment. A Testorr vacuum / inert gas furnace from Centorr (Figure 4) is mated to our 20 KIP MTS load frame, with the capability to be transferred to any other load frame. The temperature capability of this unit is in excess of 2000°C, and pressures lower than 1 x 10 6 Torr can be achieved. The furnace is compatible with argon, nitrogen and helium atmospheres.

Compaction, Sintering, Diffusion Bonding and Pressing of Metal and Ceramic Powders
Also located in the Material and Structures Laboratory is a facility for the compaction, sintering, diffusion bonding and pressing of metal and ceramic powders. Specifications of the major items of equipment in this laboratory are as follows: Hot Isostatic Press
(Figure 5): Asea Brown Bovari model QIC-3. Installed June, 1990. Maximum pressure: 30,000 psi. Maximum temperature of molebdenum furnace: 1450°C. Maximum temperature of graphite furnace: 2000°C. Dimensions of constant temperature zone: 10 cm diameter, 11 cm high. HIP temperature and pressure control and monitoring is programmable from a desktop workstation (IBM PC compatible). Cold Press: Hydraulic unit designed and fabricated by Dr. Pollock can be configured as a unidirectional or quasi-isostatic press. Maximum force: 10,000 lbs Maximum pressure: 25,000 psi. Uses interchangeable die bodies and rams. Accommodates articles up to 3 cm x 3cm x 10 cm in size, and is readily modified for larger work. Sintering Furnaces: Four furnaces
(Figure 6a & 6b) of various capacities can be programmed with multiple set points and all have inert atmosphere capability. Vacuum sintering is also done in the Centorr Vacuum Furnace.

Microstructural Analysis and Material Characterization
To ensure the highest quality metallagraphy, all required preparatory equipment is provided. This includes a Struers Secotom-10 automatic low-force diamond saw and a Struers automatic polisher with Multidoser diamond solution dispenser. (Figure 7) The lab is equiped with a Leica MEF4M metallograph, high resolution digital camera, Image-Pro imaging software, and a color laser printer for image analysis. (Figure 8) A Perkin Elmer Pyris 1 Differential Scanning Calorimeter is also utilized for measurement of transformation temperatures and latent heat associated with phase transformations. (Figure 9) The LaserMike is used to make highly accurate dimension measurements via a wide laser beam. The repeatability of this micrometer is 0.00002 in. This device has been retrofitted with a custom heating/cooling stage and is software controlled for completely autonomous testing and subsequent data acquisition. Current uses include the accurate measurement of material coefficients of thermal expansion. (Figure 10)

Pictures: 


Figure 1: MTS Axial



Figure 2: ATM axial-torsional



Figure 3: MTS Three Zone Resistive Clamshell Furnace



Figure 4: Testorr vacuum/inert gas furnace from Centorr 



Figure 5: Hot Isostatic Press  



Figure 6a: Box Furnace  



Figure 6b: Cylindrical Furnace  



Figure 7: Struers Sample Preparation



Figure 8: Leica MEF4M Metallograph  



Figure 9: Perkin Elmer Pyris 1 DSC  



Figure 10: Beta BenchMike 283 Laser Micrometer