Accession Number : AD0665701

Title :   EFFECT OF HYDROGEN ON ELECTRICAL RESISTANCE OF NIOBIUM,

Corporate Author : FOREIGN TECHNOLOGY DIV WRIGHT-PATTERSON AFB OHIO

Personal Author(s) : Pletenev,V. M.

Report Date : 23 AUG 1967

Pagination or Media Count : 10

Abstract : The effect of hydrogen on the resistivity of niobium has been investigated at 20--1000C. Hydrogen was introduced in niobium wires 1.5 mm in diameter and 1000 mm long in the amount of 0.002, 0.005, 0.01, 0.02, 0.05, 0.1 and 0.3% and the resistivity of niobium wire was determined at 20--800C and also at 500--1000C in hydrogen atmosphere under 650 mm Hg pressure. It was found that hydrogen increases the niobium resistivity, especially at temperatures up to 4000, when hydrogen content is raised from 0.01 to 0.02%. Although the mechanical properties of niobium and its alloys drop sharply at a hydrogen content of 0.02% (the elongation of niobium drops from 7--18% to 2--3%), microscopic examination revealed no structural changes. The resistivity of niobium with 0.1 and 0.3% hydrogen or that of pure niobium tested in hydrogen atmosphere under 650 mm Hg pressure increases substantially with increasing temperatures. This increase is the result of the decomposition of the secondary phase at the transition of hydrogen into solid solution. (Author)

Descriptors :   (*NIOBIUM ALLOYS, ELECTRICAL RESISTANCE), HYDROGEN, MECHANICAL PROPERTIES, WIRE, TANTALUM, MOLYBDENUM, TUNGSTEN, MICROSTRUCTURE, HEAT RESISTANT ALLOYS, HEAT RESISTANT METALS, MEASUREMENT, USSR

Subject Categories : Properties of Metals and Alloys

Distribution Statement : APPROVED FOR PUBLIC RELEASE