Avtomaticheskaya Svarka (Automatic Welding), #1, 2019, pp. 11-17
On problem of contact resistance of different-sized surfaces
E.O. Paton Electric Welding Institute of the NAS of Ukraine, 11 Kazimir Malevich Str., 03150, Kyiv, Ukraine.
A theory of electric contacts assumes an experimentally-verified inverse proportionality of electric transient resistance from applied load. The paper shows that this condition is not fulfilled at small compression forces of different-sized contacts, which take place, in particular, in excitation of electric arc by contact or breakup of thin conductor. Measurements of electric resistance of near-contact area between thin (0.75 mm diameter) conductor and sheet of steels St37 (steel 10) and 1.4301 (08Kh18N10), brass CuZn37 (L63) and aluminum alloy AlMg3 (AMg3) showed that there is an increase of electric resistance due to elastic deformation of contact surface under effect of local loading in rise of forces to specific limits. Under experiment conditions a boundary force made 2-3 daN, depending on mechanical characteristics of metal. Out of these limits a generally accepted functional dependence becomes effective. 12 Ref., 1 Tabl., 8 Fig.
Keywords: transient electric resistance, electric contacts, elastic deformation, studs welding
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