Effect of cold work on hydrogen absorption in Pd
Sakai Yuzuru; Watanabe Yasuyuki; Ohta Ken-ichiro; Kamiya Nobuyuki; Mori Kenya
Abstract:By using an electrolytic method palladium (Pd) specimens were loaded with hydrogen to investigate the effect of cold work on the hydrogen absorption property of Pd. In the successive experiments, it was clarified that the hydrogen content in the specimen remained almost constant or very slightly decreased with increasing the rate of cold work, which was contrary to the results obtained in another metals as Fe or Al. This result was interpreted as the difference of hydrogen absorption sites in metals. In Pd, hydrogen can be effectively stored in the interstitial positions of a normal lattice, which occasionally gives a quite high concentration ratio as almost n(H)/n(Pd) = 0.9 - 1.0, and lattice defects induced by cold work, which are considered as the main location of hydrogen absorption in Fe or Al, only play a subordinate role. The cold work gave damage to the normal lattice of Pd, which insignificantly contributed to the overall hydrogen absorption because the total cross sectional area of damaged lattice was relatively small. Key Words:material science, hydrogen absorption, palladium, cold work