Influence of hydrogen on magnetic properties of soft magnetic amorphous alloys
The influence of electrolytic hydrogenation on the magnetic properties of three different kinds of amorphous alloys has been investigated. The alloys studied were Fe/sub 83.3/Si/sub 3.5/B/sub 11.2/C/sub 2/, Fe/sub 38/Ni/sub 38/Mo/sub 2/Si/sub 8/B/sub 14/, and (Co/sub 86/Fe/sub 5/Cr/sub 9/)/sub 75/Si/sub 10/B/sub 15/. The experimental results showed that after hydrogenation the samples became very brittle and the soft magnetic properties degraded dramatically, but saturation magnetization sigma /sub s/ and average hyperfine field increased markedly. As hydrogen evolved from the charged samples which were placed in air at room temperature, the magnetic properties, toughness, and average hyperfine field were gradually recovered. >
Influence of hydrogen on the magnetic properties of iron‐rich metallic glasses (invited)
Melt spun and sputtered amorphous alloys from the a FexM100−x series with M=Y or Zr can be electrolytically hydrogenated up to a maximum of about 3 hydrogens per M, while retaining their mechanical integrity. Hydrogen uptake has been monitored in situ during hydrogenation by following the increase in length of the melt‐spun ribbons. Values of up to 7% have been found, and the corresponding increase in volume per absorbed hydrogen is approximately 0.5 A3. Hydrogen diffusion constants have been estimated from the mechanical relaxation, and activation energies of order 0.4 eV have been deduced. The binding energy is about 1 eV per hydrogen. Desorption at elevated temperatures preceeds crystallization of the alloys studied, and the hydrogen‐loaded materials retain much of their charge at room temperature for periods of order one year. Iron‐rich yttrium alloys have a moment close to 2 μB/Fe, but they are asperomagnets, the iron moments freezing in a random noncollinear arrangement which possesses a net moment,...
Hydrogen embrittlement of construction materials
Hydrogen embrittlement (HE) is considered to be part of stress corrosion cracking (SCC) problem and as a phenomenon of its own. In the first part of the review the present day methods for an identification of the role of HE in SCC are discussed and a general approach for any construction material is proposed to solve this question. The second part is concerned with those aspects of the HE theory which; are still not clear (acoustic data, the disposition of the fracture zones by HE ahead of the crack tip, critical hydrogen concentration) and with some newly proposed experiments. 
 
 
 
Wasserstoffversprodung von Konstruktionswerkstoffen 
 
 
 
Die Wasserstoffversprodung wird sowohl als Teilaspekt der Spannungsriskorrosion als auch als eigenstandiges Phanomen betrachtet. Im ersten Teil der vorliegenden Ubersicht werden die Methoden erortert, die heute zur Klarung der Rolle von Wasserstoffversprodung bei der Spannungsriskorrosion benutzt werden. Dabei wird eine Betrachtungsweise eingefuhrt, die sich auf alle Werkstoffe anwenden last. Der zweite Teil behandelt diejenigen Aspekte der Versprodungstheorie, die bisher noch nicht geklart werden konnten, so z. B. die Ergebnisse der Schallemissionsanalyse, die Lage der durch Wasserstoffversprodung erzeugten Bruchzone vor der Risspitze oder die kritische Wasserstoffkonzentration; dabei werden einige in neuerer Zeit zur Klarung vorgeschlagene Untersuchungsmethoden behandelt.