SUN LilingInstitute of Metal Research
,
Chinese Academy of Sciences
,
Shenyang
,
ChinaWU QiShenyang College of Technology
,
Shenyang
,
ChinaZHANG Zhiya
,
HU ZhuangqiInstitute of Metal Research
,
Chinese Academy of Sciences
,
Shenyang
,
China
金属学报(英文版)
The effect of trace element B on microstructure of directionally solidified new type Co-base superalloy is studied systematically in this paper. It is found that the addition of B makes the incipient melting temperature of the alloy decline remarkably. Compared with the alloy having a boron content of 0.05 %, the incipient melting temperature of the alloy with 0.7 % B decreases by 197℃. The primary and secondary dendrite arm spacings increase and the volume fraction of interdendritic carbides with fine microstructure becomes bigger with the enhancement of boron content. When the alloy is with 0.7wt %B, M3B2 precipitates in the interdendrites.
关键词:
horon
,
null
,
null
,
null
ZHANG Haifeng
,
LIJie
,
SONG Qihong
,
HU ZhuangqiInstitute of Metal Research
,
Chinese Academy of Sciences
,
Shenyang
,
ChinaLI WenShenyang Institute of Technology
,
Shenyang. China Manuscript received 26 April
,
1994
金属学报(英文版)
Amorphous Ni-Pd-Si ribbons were partially crystallized by relaxation treatment then secondary amorphous Ni-Pd-Si alloy powder prepared by mechanical milling. The surface states of amorphous and crystalline Ni-Pd-Si powders were studied by XRD, TEM, AES and ESCA spectra. The catalytic activities of amorphous and crystalline powders in hydrogenation of styrene was measured.The result shows that the catalytic activity of amorphous Ni-Pd-Si powder was higher than that of crystalline one by 6 times in hydrogenation of styrene.
关键词:
Ni-Pd-Si alloy
,
null
,
null
LI Geping
,
LI Dong
,
LIU Yuyin
,
HU ZhuangqiInstitute of Metal Research
,
Chinese Academy of Sciences
,
Shenyang
,
China
金属学报(英文版)
For the as-cast Ti-55 alloy, the morphology of the alloy riser consists of coarse dendrite zone and equiaxial grain zone. The second phase particles are 2.0-25 um in diameter. Some particles appear at grain boundaries, the others precipitate within grains. The shapes of the particles are mainly ellipsoids, and a few kinds of short needle-like and block v morphologies. The Nd-rich phase particles are enriched in the liquid before the inter face and are engulfed along the solidification plane-front. Finally, bands of Nd-rich phase par-ticles form parallel to the advancing solidification plane-front.
关键词:
Ti-55 alloy
,
null
,
null
