Improved Synthesis of Bulk Metallic Glasses by Current-Assisted Copper Mold Casting

2010 ◽  
Vol 13 (1-2) ◽  
pp. 38-42 ◽  
Author(s):  
Mihai Stoica ◽  
Andràs Bàrdos ◽  
Stefan Roth ◽  
Lajos K. Varga ◽  
Ludwig Schultz ◽  
...  
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.


2009 ◽  
Vol 23 (06n07) ◽  
pp. 1235-1240 ◽  
Author(s):  
QING YANG ◽  
SHUJIE PANG ◽  
RAN LI ◽  
TAO ZHANG

Bulk metallic glasses (BMGs) in pseudo-ternary ( La - Ce )- Al - Cu system with high glass-forming ability (GFA) were synthesized based on the beneficial effect of the coexistence of similar elements La and Ce with similar atomic size and various valence electronic structures on GFA. With the coexistence of La and Ce in ( La x Ce 1- x )65 Al 10 Cu 25 system, bulk metallic glasses with diameters up to 12 mm can be produced by copper mold casting. Besides the high GFA, the ( La x Ce 1- x )65 Al 10 Cu 25 BMGs with x = 0.6 and 0.7 exhibit low glass transition temperature T g around 362 K and wide supercooled liquid regions ΔT x (ΔT x = T x - T g , where T x is the onset temperature of crystallization) of about 80 K. Compared with ternary La - Al - Cu and Ce - Al - Cu systems, significant improvement of GFA for the ( La - Ce )- Al - Cu system is caused by the coexistence of similar elements La and Ce , and the mechanism is discussed from a thermodynamic viewpoint.


2009 ◽  
Vol 24 (2) ◽  
pp. 316-323 ◽  
Author(s):  
C.L. Qin ◽  
W. Zhang ◽  
K. Asami ◽  
N. Ohtsu ◽  
A. Inoue

Bulk metallic glasses (BMGs) with high thermal stability and good corrosion resistance were synthesized in the (Cu0.6Hf0.25Ti0.15)100−x−yNiyNbx system by copper mold casting. The addition of Ni element causes an extension of a supercooled liquid region (ΔTx = Tx – Tg) from 60 K for Cu60Hf25Ti15 to 70 K for (Cu0.6Hf0.25Ti0.15)95Ni5. The simultaneous addition of Ni and Nb to the alloy is effective in improving synergistically the corrosion resistance in 1 N HCl, 3 mass% NaCl, and 1 N H2SO4 + 0.01 N NaCl solutions. The highly protective Hf-, Ti-, and Nb-enriched surface film is formed by the rapid initial preferential dissolution of Cu and Ni, which is responsible for the high corrosion resistance of the alloys in the solutions examined.


2005 ◽  
Vol 20 (9) ◽  
pp. 2307-2313 ◽  
Author(s):  
W.H. Wang ◽  
J.J. Lewandowski ◽  
A.L. Greer

Interest in finding binary alloys that can form bulk metallic glasses has stimulated recent work on the Cu–Zr system, which is known to show glass formation over a wide composition range. This work focuses on copper mold casting of Cu50Zr50 (at.%), and it is shown that fully amorphous rods up to 2-mm diameter can be obtained. The primary intermetallic phase competing with glass formation on cooling is identified, and the glass-forming ability is interpreted in terms of a metastable eutectic involving this phase. Minor additions of aluminum increase the glass-forming ability: with addition of 4 at.% Al to Cu50Zr50, rods of at least 5-mm diameter can be cast fully amorphous. The improvement of glass-forming ability is related to suppression of the primary intermetallic phase.


2008 ◽  
Vol 23 (5) ◽  
pp. 1249-1257 ◽  
Author(s):  
Chun-Li Dai ◽  
Jing-Wei Deng ◽  
Ze-Xiu Zhang ◽  
Jian Xu

Starting from Cu60Zr30Ti10, the compositional dependence of bulk metallic glass (BMG) formation was revisited in the Cu−Zr−Ti ternary system. It was revealed that the optimal BMG-forming composition is located at Cu60Zr33Ti7, for which a monolithic BMG rod 4 mm in diameter can be fabricated using copper mold casting. This composition is along, although slightly off, the univariant eutectic groove for the reaction (L → Cu8Zr3 + Cu10Zr7). With respect to the corresponding Cu−Zr binary alloys, Ti has a significant effect on further stabilizing the liquid, thus increasing the glass-forming ability. For the Cu60Zr40−yTiy (3 ⩽ y ⩽ 10) series BMGs, the glass transition temperature Tg decreased with increasing Ti content, at a rate of about 2.8 K/at.%. Among these BMGs, significant compositional dependence of compressive plasticity is not observed, irrespective of the Tg change. Cu60Zr33Ti7 glass exhibits maximum fracture strength around 2160 MPa.


2019 ◽  
Vol 56 (4) ◽  
pp. 700-704
Author(s):  
Carmen Opris ◽  
Cosmin Codrean ◽  
Dragos Buzdugan ◽  
Petru Hididis

Bulk metallic glasses (BMGs) represent a viable alternative for replacing classic materials used in medical devices. This paper presents the research conducted in order to obtain copper based BMGs using two different chemical compositions: Cu48Zr47Al5 and Cu45Zr45Al5Ag5. The samples were obtained by copper mold casting and their structure and properties were investigated using X-Ray diffraction (XRD), differential scanning calorimetry (DSC) and optical microscopy.


2015 ◽  
Vol 1114 ◽  
pp. 68-75
Author(s):  
Mariana Lucaci ◽  
Delia Patroi ◽  
Violeta Tsakiris ◽  
Magdalena Valentina Lungu ◽  
Eugen Manta ◽  
...  

Researches and developments were carried out for obtaining of bulk metallic glass (BMG) from the Fe-Cr-Ni-Si-B system. The used processing methods were copper mold casting and melt spinning method. The resulted materials are in form of sheets with sizes of 69.7 x 64 x 3/1.5 mm and of strips with thickness less than 50 microns, which were obtained by varying the melt spin technological parameters. The both processing variants are not suitable for obtaining such of alloy in bulk metallic glass form. Adding of zirconium to this alloy produces bulk metallic glasses only for the melt spin products. The DSC analysis emphases that the zirconium modified alloy processed by melt spinning method exhibits a high glass forming ability (GFA).


2002 ◽  
Vol 43 (9) ◽  
pp. 2357-2359 ◽  
Author(s):  
Liqun Ma ◽  
Limin Wang ◽  
Tao Zhang ◽  
Akihisa Inoue

2014 ◽  
Vol 783-786 ◽  
pp. 1895-1900 ◽  
Author(s):  
Teruo Bitoh

The effect of B2O3 fluxing on the glass-forming ability (GFA), the structure and the soft magnetic properties of Fe (-Co)-B-Si-Nb bulk metallic glasses (BMGs) has been investigated. The large Fe-Co-B-Si-Nb BMG specimens with diameters up to 7.7 mm, which is approximately 1.5 times as large as that of the maximum diameter of the copper mold cast one (= 5 mm), were prepared by the fluxing and water quenching. Thus the GFA of the Fe-Co-B-Si-Nb BMG are improved by the fluxing. It was confirmed that the soft magnetic properties of the Fe-Co-B-Si-Nb BMG are also improved by the fluxing. On the other hand, it was found for the Co-free Fe-B-Si-Nb BMG that the B2O3 fluxing promotes the precipitation of the α-Fe (-Si) and Fe2B phases in the central region of the specimens; i.e., the GFA of the Fe-B-Si-Nb BMG is decreased by the fluxing. The Fe-B-Si-Nb BMG specimens show a flat hysteresis loop, indicating a good linear relationship between the magnetic induction and the applied magnetic field. These results of the Fe-B-Si-Nb BMG show that it is possible to develop a new soft magnetic material that exhibits constant permeability, which is necessary for producing inductors and choke coils.


2011 ◽  
Vol 399-401 ◽  
pp. 1012-1015
Author(s):  
Jian Peng Wu ◽  
Shan Dong Li ◽  
Mei Mei Liu ◽  
Xin Le Cai ◽  
Yi Hu ◽  
...  

The effect of C substitution on the glass forming ability (GFA) and soft magnetic properties of Fe-based bulk metallic glasses (BMG) Fe79.4-xCxSi3.5B5.1P8.9Mo3Mn0.1(x = 4.2, 5.2, and 7.0) alloys have been investigated. It is revealed that fully glassy alloy rods with diameters up to 4 mm can be prepared by conventional copper mold casting method even using the low-cost industrial Fe-P master alloy. Properly substituting of Fe by C gives rise to an enhancement of GFA. Moreover, all the samples exhibit good soft magnetic properties with high saturation magnetization up to 1.16 T and low coercivity of 204 A/m.


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