K. Koyama et al., OBSERVATION OF IMPURITY HYDROGEN EVOLVED FROM ALUMINUM DURING DEFORMATION BY MEANS OF SILVER DECORATION TECHNIQUE, Nippon Kinzoku Gakkaishi, 62(8), 1998, pp. 742-747
Silver decoration technique was applied to high purity aluminum specim
ens with two impurity hydrogen levels to visualize the hydrogen atoms
evolved from the specimen during tensile deformation. The specimens we
re deformed by about 5% in the silver decoration solution of K[Ag(CN)(
2)]. A number of needle-shaped deposits indicating hydrogen evolution
were revealed along coarse slip lines produced by the deformation. The
deposits were identified by AES not as metallic silver but as AgCN cr
ystals. The amount of the deposits was affected significantly by the i
mpurity hydrogen content of the specimen and by pH and temperature of
the silver decoration solution, but not markedly by K[Ag(CN)(2)] conce
ntration in the solution. This new method using silver decoration tech
nique is a relatively simple and valuable tool for the study of hydrog
en embrittlement of metals and alloys.