1883 KB41 KB199920252013Karabay, Sedatletnik:59številka:7/8str. 451-461, SI 84ISSN:0039-2480COBISSID:13076507URN:URN:NBN:SI:doc-PHOGG1AYenAssociation of Mechanical Engineers and Technicians of Slovenia et al.Zveza strojnih inženirjev in tehnikov Slovenije et al.Strojniški vestnikAA6101 feedstockAlB modificationconductivityelektrična prevodnostlightning strikemodifikacija z AlB2optical ground wirepretrganje žicesamonosni optični kabel OPGWsurovec iz AA6101udar strelewire breakageModification of conductive material AA6101 of OPGW conductors against lightning strikes|In this article, failure in lightning tests and the overcoming of its destructive effects by improving the new generation of optical grounding wire (OPGW) are presented. The designed composite structure for transmission lines in Turkey is composed of six galvanized steel wires, one stainless steel tube with multiple glass fibres and 12 aluminium alloy AA6101 wires. Test samples from prototype OPGW successfully passed short circuit requirements but failed in tests of lightning strikes. Consequently, a material modification was applied by feeding 3% AlB2 master alloy as a 9.5 mm rod into molten metal in the tundish when the metal flows from the melting furnace to the vertical log casting mould. Logs cast from AA6101 are used to manufacture feedstock by means of extrusion press. Impaired electrical conductivity of the AA6101 due to the presence of heavy metal impurities such as Ti, Cr and V should be increased to pass the tests. Following this, the transition metals were transformed into insoluble borides from solution after inoculation with AlB2. As a result, the conductivity of wires drawn from feedstock produced by extrusion press with the modified AA6101 billets was increased from 52.5 to 57% IACS. Consequently, the modified OPGW with AlB2 satisfied the requirements of international standards related to lightning testsTEXTznanstveno časopisjejournalsSlovenian National E-content AggregatorNational and University Library of SloveniaUniverza v Ljubljani, Fakulteta za strojništvo