NASA Logo

NTRS

NTRS - NASA Technical Reports Server

Collections About News Help Login
Back to Results
Advances in Non-contact Measurement of Creep PropertiesOur team has developed a novel approach to measuring creep at extremely high temperatures using electrostatic levitation (ESL). This method has been demonstrated on niobium up to 2300 C, while ESL has melted tungsten (3400 C). High-precision machined spheres of the sample are levitated in the NASA MSFC ESL, a national user facility, and heated with a laser. The laser is aligned off-center so that the absorbed photons transfer their momentum to the sample, causing it to rotate at up to 250,000+ RPM. The rapid rotation loads the sample through centripetal acceleration, causing it to deform. The deformation of the sample is captured on high-speed video, which is analyzed by machine-vision software from the University of Massachusetts. The deformations are compared to finite element models to determine the constitutive constants in the creep relation. Furthermore, the noncontact method exploits stress gradients within the sample to determine the stress exponent in a single test. This method was validated in collaboration with the University of Tennessee for niobium at 1985 C, with agreement within the uncertainty of the conventional measurements. A similar method is being employed on Ultra-High-Temperature ZrB2- SiC composites, which may see application in rocket nozzles and sharp leading edges for hypersonic vehicles.
Document ID
20090028680
Acquisition Source
Marshall Space Flight Center
Document Type
Conference Paper
Authors
Hyers, Robert W. (Massachusetts Univ. MA, United States)
Canepari, Stacy (Massachusetts Univ. MA, United States)
Rogers, Jan. R. (NASA Marshall Space Flight Center Huntsville, AL, United States)
Date Acquired
August 24, 2013
Publication Date
June 22, 2009
Subject Category
Composite Materials
Report/Patent Number
M09-0522
Meeting Information
Meeting: 2009 National Space and Missile Materials Symposium
Location: Henderson, NV
Country: United States
Start Date: June 22, 2009
End Date: June 26, 2009
Funding Number(s)
CONTRACT_GRANT: NNM04AA78G
CONTRACT_GRANT: NNM04AA19A
CONTRACT_GRANT: NGT8-52948
Distribution Limits
Public
Copyright
Public Use Permitted.

Related Records

There are no records associated with this record.
No Preview Available