THE HYDROGEN-INDUCED STRUCTURAL RELAXATION AND CRYSTALLIZATION OBSERVED IN AMORPHOUS CU50ZR50 AND CU60ZR40

Hydrogen thermal desorption (HTD) from amorphous Cu50Zr50 and Cu60Zr40 was investigated for the hydrogen concentration C(H) ([H]/[metal]) below 40 at.%. For amorphous Cu50Zr50, the onset temperature T(X,S) of partial crystallization does not exhibit a decrease as a result of HTD, but hydrogen-induced structural relaxation (HISR) takes place. In the C(H) scale, HISR proceeds intermittently: HISR 1 proceeds below 650 K for C(H) beyond 6.5 at.%, HISR 2 at room temperature for C(H) beyond 25 at.%, and HISR 3 at room temperature for C(H beyond 32 at.%. On the contrary, for amorphous Cu60Zr40, T(X,S) decreases strongly with increasing C(H), where T(X,S) found to decrease linearly with C(H) remaining in a specimen at T(X,S). The site energy of hydrogen and the effect of hydrogen on the stability of these amorphous alloys are discussed.