Radiant energy – Inspection of solids or liquids by charged particles – Analyte supports
Patent
1995-12-08
1997-02-25
Anderson, Bruce C.
Radiant energy
Inspection of solids or liquids by charged particles
Analyte supports
25044211, G01N 23225
Patent
active
056061684
DESCRIPTION:
BRIEF SUMMARY
This application is a 371 of PCT/FR94/00495, Apr. 24, 1994, published as WO94/25846, Nov. 10, 1994.
This invention concerns an in situ tensile testing machine designed to be integrated into the observation chamber of a scanning electron microscope (S.E.M.), and to receive a specimen interposed between two anchoring elements capable of allowing the sample to be brought under traction via its ends, in order to study its behaviour.
It concerns, for example, the carrying out of observations by scanning electron microscope to follow the chronology of events at the time of plastic deformation of materials (damage, location of deformations, etc.).
This allows observation on the microscopic scale of the appearance and evolution of slip lines, shear bands, interfacial decoherences, cracks, and even deformation heterogeneities in polycrystals.
The following experiments in particular make use of in situ tensile testing at ambient temperature:
1) the study of metallic matrix composites, particularly aluminium matrix composites and those reinforced with particles of silicon carbide (SiC), with emphasis on local damage mechanisms, especially at the matrix-SiC interface level;
2) the study of materials having very high mechanical characteristics prepared by powder metallurgy, with interest more particularly focused on the detrimental effects of exogenous inclusions, introduced during preparation;
3) the study of plastic deformation instabilities in shear bands in mono-, multi- and polycrystals.
4) the study of plastic deformation heterogeneities in polycrystals, in order to characterise the plastic deformation mechanisms of polycrystalline aggregates.
At the present time, traction machines producing high forces are bulky and do not therefore allow a material to be characterised during its deformation through its analysis by scanning electron microscope. Now, in view of that mentioned above, the scientific merits of such a characterisation are very obvious, notably for the study of certain "technological" materials, to test certain behavioural models under real conditions, or even to study deformation instabilities or heterogeneities.
Moreover, in situ devices currently available on the market cannot replace conventional machines, notably because of inferior mechanical rigidity, or a less efficient sample anchoring system, or less precise checking of the mechanical displacements of the traction heads leading to generally less accurate testing.
Moreover, these devices are heavy and bulky, requiring modifications of the access door to the chamber of the S.E.M., or may only be partly modular, with the specimen traction motor placed outside the chamber so as to avoid the effects of magnetic interference of the electronic beam, or they may not allow a sufficient nominal load to be imposed.
Furthermore, it is important to mention that the systems generally adopted to anchor the sample comprise either self-locking jaws, which are unable to guarantee automatic alignment or the absence of sliding of the sample in the heads, or the broaching of the sample in a clevis. Neither of these two systems allows the sample to be thermally insulated; tests at high temperature are therefore only possible on samples with a long useful length and small cross-section, in order to minimise heat conduction away from the heated useful zone towards the anchoring heads of the sample. These anchoring systems therefore present a major drawback for traction tests on solid samples at high temperatures, because of the excessive thermal conduction towards the fixing heads and frame of the machine; substantial heating power would be required to attain high temperatures (>600.degree. C.); in addition, during testing over a long period of time, the process would result in considerable heating of the fixing heads and the rest of the machine, which may in time cause irreversible deterioration of the machine's characteristics.
Thus, patent JP-A-03273134 describes a material testing machine comprising a scanning electron microscope. A sample is gripped between
REFERENCES:
patent: 3107522 (1963-10-01), Bonewits
patent: 3919558 (1975-11-01), Brouillette et al.
patent: 4548085 (1985-10-01), Grundy
patent: 4721000 (1988-01-01), Scanlon
patent: 4970895 (1990-11-01), Houghton
patent: 4996433 (1991-02-01), Jones et al.
patent: 5056372 (1991-10-01), Estano
patent: 5195379 (1993-03-01), Cussac et al.
patent: 5355683 (1994-10-01), Taylor
Patent Abstracts of Japan, vol. 16, No. 92 (P. 1321), dated Mar. 6, 1992, corresponding to Japanese Patent Publication No. 3-273134 (Shimadzu Corp.), dated Dec. 4, 1991 (English Language).
Patent Abstract of Japanese Patent Publication No. 58-218636 (Tokyo Shibaura Denki K.K.), published on Dec. 19, 1983 (English language).
Patent Abstracts of Japan, vol. 8, No. 72 (P-265), dated Apr. 4, 1984.
Patent Abstracts of Japan, vol. 16, No. 92 (P-1321), dated Mar. 6, 1992. International Search Report and Annex.
Chiron Remi
Fryet Jacques
Viaris De Lesegno Patrick
Anderson Bruce C.
Centre National de la Recherche Scientifique
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