TY - JOUR
T1 - Amorphization by mechanical alloying
T2 - The role of mixtures of intermetallics
AU - Lee, P. Y.
AU - Jang, J.
AU - Koch, C. C.
N1 - Funding Information:
The authors wish to thank S. A. Myers for assistancew ith the analytical TEM measurements.T his researchw as sponsored by the National Science Foundation under grant DMR-8318561.
PY - 1988/6
Y1 - 1988/6
N2 - This paper reports selected results of a continuing study of the systematics and mechanisms of amorphization by mechanical alloying of mixtures of intermetallic compound powders. Mechanical alloying was carried out on mixtures of "line" intermetallic compounds (i.e. those having a narrow range of homogeneity) in the following binary alloy systems: Cr-Ti, Mn-Ti, Cu-Ti, Fe-Ti, Co-Ti, Ni-Ti, Cu-Zr, Ni-Zr and Mn-Si. Amorphization by mechanical alloying was observed to be complete, to the resolution of X-ray diffraction, for intermetallic compound mixtures (e.g. NiZr2 + Ni11Zr9 → a-Ni40Zr60) in all the above systems except Cr-Ti, which exhibited partial amorphization, and Mn-Si, which showed no amorphization. The amorphization tendencies could not be predicted from calculated enthalpies of mixing for the amorphous alloys, all of which were negative, or from calculated differences in free energy between the amorphous phase and the mixture of equilibrium intermetallic compounds. Preliminary transmission electron microscopy studies of the evolution of the amorphous phase for the system NiZr2 + Ni11Zr9 → a-Ni40Zr60 revealed an amorphous halo-like region surrounding the transforming intermetallic particles in an amorphous matrix. Energy dispersive X-ray analysis measurements indicate that the halo-like region has a composition which falls between those of the intermetallic particle and the amorphous matrix.
AB - This paper reports selected results of a continuing study of the systematics and mechanisms of amorphization by mechanical alloying of mixtures of intermetallic compound powders. Mechanical alloying was carried out on mixtures of "line" intermetallic compounds (i.e. those having a narrow range of homogeneity) in the following binary alloy systems: Cr-Ti, Mn-Ti, Cu-Ti, Fe-Ti, Co-Ti, Ni-Ti, Cu-Zr, Ni-Zr and Mn-Si. Amorphization by mechanical alloying was observed to be complete, to the resolution of X-ray diffraction, for intermetallic compound mixtures (e.g. NiZr2 + Ni11Zr9 → a-Ni40Zr60) in all the above systems except Cr-Ti, which exhibited partial amorphization, and Mn-Si, which showed no amorphization. The amorphization tendencies could not be predicted from calculated enthalpies of mixing for the amorphous alloys, all of which were negative, or from calculated differences in free energy between the amorphous phase and the mixture of equilibrium intermetallic compounds. Preliminary transmission electron microscopy studies of the evolution of the amorphous phase for the system NiZr2 + Ni11Zr9 → a-Ni40Zr60 revealed an amorphous halo-like region surrounding the transforming intermetallic particles in an amorphous matrix. Energy dispersive X-ray analysis measurements indicate that the halo-like region has a composition which falls between those of the intermetallic particle and the amorphous matrix.
UR - http://www.scopus.com/inward/record.url?scp=0024017741&partnerID=8YFLogxK
U2 - 10.1016/0022-5088(88)90369-4
DO - 10.1016/0022-5088(88)90369-4
M3 - 期刊論文
AN - SCOPUS:0024017741
SN - 0022-5088
VL - 140
SP - 73
EP - 83
JO - Journal of The Less-Common Metals
JF - Journal of The Less-Common Metals
IS - C
ER -