scholarly journals Microstructure and Mechanical Properties of Cr, Mo, Fe, Ta Modified Pd-Ni-Cu-P Glassy Alloys Prepared by Copper-Mold Casting

2003 ◽  
Vol 44 (1) ◽  
pp. 188-196 ◽  
Author(s):  
Chaoli Ma ◽  
Akihisa Inoue
2010 ◽  
Vol 504 ◽  
pp. S483-S486 ◽  
Author(s):  
S. Scudino ◽  
M. Sakaliyska ◽  
K.B. Surreddi ◽  
F. Ali ◽  
J. Eckert

2009 ◽  
Vol 24 (9) ◽  
pp. 2935-2940 ◽  
Author(s):  
Wei Zhang ◽  
Qingsheng Zhang ◽  
Chunling Qin ◽  
Akihisa Inoue

New Cu-based bulk glassy alloys (BGAs) with high glass-forming ability (GFA) were synthesized in a Cu-Zr-Al-Ag system. As the compositions of Cu-Zr-Al-Ag alloys with lower Ag and Al content shifted to the Cu-rich range, the supercooled liquid region, reduced glass transition temperature, and γ value increased, leading to the improvement of GFA. The best GFA is located around Cu47Zr45Al5Ag3, which is close to eutectic. Fully glassy samples with diameters up to 15 mm were fabricated by copper mold casting. These Cu-based BGAs exhibit excellent mechanical properties under compression. A large Young's modulus of 104–111 GPa, high fracture strength of 1905–1942 MPa, and distinct plastic strain of 0.002–0.011 were obtained. Additionally, the BGAs also show good corrosion resistance in 1 N H2SO4 solution.


2011 ◽  
Vol 148-149 ◽  
pp. 241-244 ◽  
Author(s):  
Feng Xiang Qin ◽  
Guo Qiang Xie ◽  
Zhen Hua Dan ◽  
Akihisa Inoue

Ti-based bulk metallic glasses with minor addition of Ag, Au or Pt elements were prepared by copper mold casting. The Microstructure of the as-cast samples was examined by TEM. Nanoparticles identified as cubic Pd3Ti with crystal planes of (111), (200), (220) and (311) are observed in all the alloys modified by the minor addition of Ag, Au or Pt. The results revealed that the glassy/nanoparticle composited alloys exhibited high strength about 2000 MPa and plastic strain between 1.5-10% due to the inhibition of propagation of shear band.


2006 ◽  
Vol 20 (25n27) ◽  
pp. 3617-3622 ◽  
Author(s):  
QINGJUN CHEN ◽  
DELIANG ZHANG ◽  
JUN SHEN ◽  
HONGBO FAN ◽  
JIANFEI SUN ◽  
...  

Fe -based bulk amorphous rods of 3 mm in diameter and a composition of Fe 41 Cr 15 Mo 14 C 15 B 6 Y 2 Co 7 were produced by copper mold casting. The as-cast amorphous rods contain a small (2%) fraction of pores. To close the pores, samples cut from the amorphous rods were hot isostatically pressed (hipped) at 863 K, which is in the supercooled liquid temperature range between the glass transition temperature and the crystallization temperature of the amorphous phase, and under a pressure of 200 Mpa. Microstructure examination of the hipped samples shows that hipping results in an increase of the density of the samples from 7.9 g/cm3 to 8.0 g/cm3, and a decrease of the porosity level from 2% to 1%, and that a very small fraction of unknown crystalline phase form. As a result of these microstructure change caused by hipping, the average room temperature compressive fracture strength of the bulk metallic glass (BMG) decrease from 3500 Mpa to 3000 MPa, while the strain to fracture changes little from 1.5% to 1.4%. The mechanisms of the effect of hipping on microstructure and mechanical properties of the Fe -based BMG are discussed.


2007 ◽  
Vol 539-543 ◽  
pp. 2082-2087
Author(s):  
Bao Long Shen ◽  
Akihisa Inoue

Fe- and Co-based bulk glassy alloys (BGAs) with diameters up to 5 and 4 mm were formed respectively in (Fe,Co)-B-Si-Nb system by copper mold casting. The Fe-based glassy alloys in [(Fe1-xCox)0.75B0.2Si0.05]96Nb4 system exhibit saturation magnetization (Is) of 0.84-1.13 T and low coercive force (Hc) of 1.5-2.7 A/m. Its BGAs exhibit superhigh strength ( σ f) of 3900-4250 MPa, Young’s modulus (E) of 190-210 GPa, elastic strain (εe) of 0.02 and plastic strain (εp) of 0.0025. For the Co-based glassy alloys in [(Co1-xFex)0.75B0.2Si0.05]96Nb4 system, in addition to superhigh σ f of 3980-4170 MPa, they also exhibit excellent soft magnetic properties, i.e., Is of 0.71-0.97 T, Hc of 0.7-1.8 A/m, high effective permeability (μe) of 1.48-3.25×104 at 1 kHz under a field of 1 A/m, and extremely low saturation magnetostriction (λs) of 0.55-5.76×10-6.


2003 ◽  
Vol 18 (6) ◽  
pp. 1435-1440 ◽  
Author(s):  
Akihisa Inoue ◽  
Wei Zhang

New Cu-based bulk glassy alloys with large supercooled liquid regions and high mechanical strength were formed in Cu–Hf–Al ternary systems. The large supercooled liquid region exceeding 70 K was obtained in the composition range of 40 at.% Hf at 2.5% Al, 37.5–50% Hf at 5% Al, and 45% Hf at 7.5% Al. The largest supercooled liquid region ΔTx(= Tx – Tg) was 91 K for Cu50Hf45Al5 alloy, and the highest reduced glass-transition temperature was 0.63 for Cu50Hf42.5Al7.5 and Cu52.5Hf40Al7.5 alloys. The alloys with large ΔTx values above 50 K were formed into bulk glassy rods with diameters up to 3 mm by copper mold casting, and the glassy alloy rods exhibited high compressive fracture strength of 2260 to 2370 MPa and Young's modulus of 121 to 128 GPa combined with elastic elongation of 1.9% to 2.0% and plastic elongation of 0.2% to 0.6%. No bulk glassy alloys were formed in the Cu–Hf binary system by copper mold casting, and, hence, the addition of 2.5% to 7.5% Al to Cu–Hf alloys was very effective for increasing glass-forming ability as well as the stabilization of supercooled liquid. The effectiveness can be interpreted on the basis of the concept of the formation of a unique glassy structure in special multicomponent alloys with the three component rules.


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