Measuring and testing – Hardness – By penetrator or indentor
Patent
1989-03-15
1989-08-01
Levy, Stewart J.
Measuring and testing
Hardness
By penetrator or indentor
G01N 342
Patent
active
048523976
ABSTRACT:
Apparatus and methods for the in-field measurement of mechanical and physical properties of metallic structures. The apparatus is a Field Indentation Microprobe (FIM) using an indenter that is caused to contact and indent the structure using cyclically applied and released successive increasing loads at the same location. The load and penetration depth data during both cyclic loading and unloading are used to determine the flow properties and fracture toughness of the structure. An X-Y driven testing head supports a load cell which is connected to an indenter holder and the indenter. A displacement transducer is carried by the load cell to measure the depth of penetration of the indenter into the structure, and one or more ultrasonic transducers determine the physical phenomena such as crack size, material pile-up around indentation, and residual stress presence and orientation. A polishing tool is provided to prepare the surface of the structure prior to indentation. Also, a video camera is provided to view the surface, and to measure the final diameter of indentation. A data acquisition system and a computer appropriately programmed for automated testing and for acquiring and processing test data are used to provide the desired mechanical and physical property information. Accordingly, changes in local mechanical and physical properties of a structure, due to either normal service or damage, can be determined nondestructively in the field, and hence structural integrity can be evaluated.
REFERENCES:
patent: 2158008 (1939-05-01), Grant, Jr.
patent: 3822946 (1974-07-01), Rynkowski
patent: 3879982 (1975-04-01), Schmidt
patent: 4199976 (1980-04-01), Edward
patent: 4294118 (1981-10-01), Shiraiwa et al.
patent: 4331026 (1982-05-01), Howard et al.
patent: 4433582 (1984-02-01), Joosten
patent: 4437332 (1984-03-01), Pittaro
patent: 4621523 (1986-11-01), Shabel et al.
patent: 4635471 (1987-01-01), Rogers et al.
patent: 4671104 (1987-06-01), Fischer
patent: 4699000 (1987-10-01), Lashmore et al.
patent: 4764882 (1988-08-01), Braschel et al.
"The Use of Miniaturized Tests to Predict Flow Properties and Estimate Fracture Toughness in Deformed Steel Plates", by F. M. Haggag et al., ASM Proceedings of the Fracture-Mechanism Program of the International Conference and Exposition on Fatigue, Corrosition Cracking, Fracture Mechanics and Failure Analysis, 2-6 Dec. 1985, Salt Lake City, Utah, pp. 399-406.
"Determination of Luders Strains and Flow Properties from Hardness/Microhardness Tests", by F. M. Haggag and G. E. Lucas, Metallurgical Transactions A, vol. 14A, pp. 1607-1613.
Levy Stewart J.
Raevis Robert R.
LandOfFree
Field indentation microprobe for structural integrity evaluation does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Field indentation microprobe for structural integrity evaluation, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Field indentation microprobe for structural integrity evaluation will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-124079