Formation of Large Bulk [(Fe0.5Co0.5)0.75B0.20Si0.05]96Nb4 Glassy Alloy by Flux Melting and Water Quenching

2005 ◽  
Vol 903 ◽  
Author(s):  
Teruo Bitoh ◽  
Akihiro Makino ◽  
Akihisa Inoue ◽  
A. Lindsay Greer
Keyword(s):  
Glassy Alloy ◽  
Water Quenching ◽  
Maximum Diameter ◽  
Copper Mold ◽  
Glass Forming ◽  
Copper Mold Casting ◽  
Large Bulk ◽  
Nucleation Sites ◽  
Mold Casting ◽  
Molten Flux

AbstractThe large bulk glassy [(Fe0.5Co0.5)0.75B0.20Si0.05]96Nb4 alloy specimens with the diameters up to 7.7 mm have been prepared by water quenching the melt immersed in the molten flux of B2O3. The maximum diameter of the obtained specimens is approximately 1.5 times as large as the pre-vious result for copper mold casting should be cooled at the higher rate than the of water quenching. The flux melting improves the glass-forming ability by the elimination of oxides and other inclusion in the molten metal which act as heterogeneous nucleation sites for crystallization.

Soft Magnetic Bulk Glassy Alloy Synthesized by Flux Melting and Water Quenching

2007 ◽  
Vol 539-543 ◽  
pp. 1921-1925 ◽  
Author(s):  
Akihiro Makino ◽  
Teruo Bitoh ◽  
Akihisa Inoue ◽  
A. Lindsay Greer
Keyword(s):  
Cooling Rate ◽  
Glassy Alloy ◽  
Glass Forming Ability ◽  
Water Quenching ◽  
Soft Magnetic ◽  
Glass Forming ◽  
Large Bulk ◽  
Mold Casting ◽  
Molten Flux ◽  
Bulk Glassy Alloy

The flux treatment was applied to increase the glass-forming ability of a glassy [(Fe0.5Co0.5)0.75B0.20Si0.05]96Nb4 alloy. The large bulk glassy specimen with diameter of 7.7 mm was prepared by water quenching the melt immersed in the molten flux of B2O3. The diameter of the specimens is approximately 1.5 times as large as the previous result, even though the cooling rate of copper mold casting should be much higher than that of water quenching. The critical cooling rate for a glassy phase is 150 - 170 K/s, which is much slower than 500 K/s without the flux treatment. The flux treatment improves the glass-forming ability by cleaning the molten metal where heterogeneous nucleation is difficult to take place.

Formation and mechanical properties of Cu–Hf–Al bulk glassy alloys with a large supercooled liquid region of over 90 K

2003 ◽  
Vol 18 (6) ◽  
pp. 1435-1440 ◽  
Author(s):  
Akihisa Inoue ◽  
Wei Zhang
Keyword(s):  
Glassy Alloy ◽  
Ternary Systems ◽  
Supercooled Liquid ◽  
Supercooled Liquid Region ◽  
Liquid Region ◽  
Copper Mold ◽  
Glass Forming ◽  
Copper Mold Casting ◽  
Glassy Alloys ◽  
Mold Casting

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.

Formation of Mg–Cu–Ni–Ag–Zn–Y–Gd Bulk Glassy Alloy by Casting into Cone-shaped Copper Mold in Air Atmosphere

2005 ◽  
Vol 20 (6) ◽  
pp. 1465-1469 ◽  
Author(s):  
E.S. Park ◽  
D.H. Kim
Keyword(s):  
Glass Formation ◽  
Glassy Alloy ◽  
Compressive Loading ◽  
Maximum Diameter ◽  
Copper Mold ◽  
Casting Method ◽  
Glass Forming ◽  
Air Atmosphere ◽  
Mold Casting ◽  
Bulk Glassy Alloy

A new Mg–Cu–Ni–Ag–Zn–Y–Gd alloy with significantly improved glass forming ability (GFA) was developed in this work. Mg65Cu7.5Ni7.5Ag5Zn5Y5Gd5 bulk metallic glass (BMG) with a diameter of 14 mm was successfully fabricated by conventional copper mold casting method in air atmosphere. The critical cooling rate for glass formation was estimated to be about 20 K/s. When the maximum diameter for glass formation was compared with those previously reported for Mg-based alloys, the Mg65Cu7.5Ni7.5Ag5Zn5Y5Gd5 alloy showed the highest GFA. However, when the GFA was compared with those of Mg-TM-RE alloys (TM: Cu, Ni, Zn, and Ag; RE: Y and Gd), the significant improved GFA of the Mg–Cu–Ni–Zn–Ag–Y–Gd alloy cannot be properly represented by ΔTx, Trg, K, and γ parameters. In contrast to most of the Mg-based BMGs reported so far, the Mg65Cu7.5Ni7.5Ag5Zn5Y5Gd5 BMG exhibits yielding and plastic deformation during compressive loading.

Formation of Ca–Mg–Zn bulk glassy alloy by casting into cone-shaped copper mold

2004 ◽  
Vol 19 (3) ◽  
pp. 685-688 ◽  
Author(s):  
E.S. Park ◽  
D.H. Kim
Keyword(s):  
Glassy Alloy ◽  
Copper Mold ◽  
Casting Method ◽  
Glass Forming ◽  
Copper Mold Casting ◽  
Air Atmosphere ◽  
Mold Casting ◽  
Bulk Glassy Alloy ◽  
Zn Alloy ◽  
Zn Alloys

A new Ca–Mg–Zn alloys having significantly improved glass-forming ability (GFA) has been developed. The ternary Ca65Mg15Zn20 bulk metallic glass with diameter of at least 15 mm is successfully fabricated by conventional copper-mold casting method in air atmosphere. The critical cooling rate for glass formation in the cone-shaped copper mold is less than 20 K/s. When compared with the GFA of Ca–Mg–M (M: Cu, Ni, and Ag) alloys, the significantly improved GFA of the Ca–Mg–Zn alloy cannot be represented by ΔTx, Trg, K, and γ parameters.

Effects of C Addition on Glass-Forming in FeCPSiBMoMn Bulk Metallic with Good Soft-Magnetic Properties

2011 ◽  
Vol 399-401 ◽  
pp. 1012-1015
Author(s):  
Jian Peng Wu ◽  
Shan Dong Li ◽  
Mei Mei Liu ◽  
Xin Le Cai ◽  
Yi Hu ◽  
...  
Keyword(s):  
Magnetic Properties ◽  
Metallic Glasses ◽  
Low Cost ◽  
Glassy Alloy ◽  
Soft Magnetic Properties ◽  
Soft Magnetic ◽  
Casting Method ◽  
Glass Forming ◽  
Copper Mold Casting ◽  
Mold Casting

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.

Fabrication of Cu–Zr–Ag–Al glassy alloy samples with a diameter of 20 mm by water quenching

2008 ◽  
Vol 23 (5) ◽  
pp. 1452-1456 ◽  
Author(s):  
Wei Zhang ◽  
Qingsheng Zhang ◽  
Akihisa Inoue
Keyword(s):  
Glassy Alloy ◽  
Supercooled Liquid ◽  
Underlying Mechanism ◽  
Melting Behavior ◽  
Supercooled Liquid Region ◽  
Water Quenching ◽  
Liquid Region ◽  
Glass Forming ◽  
Glassy Alloys ◽  
Mold Casting

The melting behavior, thermal stability, and glass-forming ability (GFA) of Cu84−xZrxAg8Al8 (x = 42 to 50) glassy alloys were investigated. The alloy with x = 46 exhibits the highest reduced glass transition temperature (Trg). However, the best GFA was obtained for alloy with x = 48 corresponding to the largest supercooled liquid region (ΔTx) and a deep eutectic composition. At the best GFA composition, full glassy samples with diameters of over 20 mm could be fabricated by injection copper mold casting and water quenching without flux. The underlying mechanism of the unusual GFA of the alloy is discussed.

Understanding the Glass-forming Ability of Cu50Zr50 Alloys in Terms of a Metastable Eutectic

2005 ◽  
Vol 20 (9) ◽  
pp. 2307-2313 ◽  
Author(s):  
W.H. Wang ◽  
J.J. Lewandowski ◽  
A.L. Greer
Keyword(s):  
Metallic Glasses ◽  
Glass Formation ◽  
Composition Range ◽  
Intermetallic Phase ◽  
Glass Forming Ability ◽  
Copper Mold ◽  
Wide Composition Range ◽  
Glass Forming ◽  
Copper Mold Casting ◽  
Mold Casting

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.

Formation and properties of new Cu-based bulk glassy alloys with critical diameters up to 1.5 cm

2009 ◽  
Vol 24 (9) ◽  
pp. 2935-2940 ◽  
Author(s):  
Wei Zhang ◽  
Qingsheng Zhang ◽  
Chunling Qin ◽  
Akihisa Inoue
Keyword(s):  
Supercooled Liquid ◽  
Supercooled Liquid Region ◽  
Liquid Region ◽  
Copper Mold ◽  
High Fracture ◽  
Al Content ◽  
Glass Forming ◽  
Copper Mold Casting ◽  
Glassy Alloys ◽  
Mold Casting

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.

EFFECT OF COEXISTENCE OF SIMILAR ELEMENTS La AND Ce ON FORMATION OF (La-Ce)-Al-Cu BULK METALLIC GLASSES

2009 ◽  
Vol 23 (06n07) ◽  
pp. 1235-1240 ◽  
Author(s):  
QING YANG ◽  
SHUJIE PANG ◽  
RAN LI ◽  
TAO ZHANG
Keyword(s):  
Metallic Glasses ◽  
Electronic Structures ◽  
Bulk Metallic Glasses ◽  
Supercooled Liquid ◽  
Copper Mold ◽  
Atomic Size ◽  
Glass Forming ◽  
Copper Mold Casting ◽  
Mold Casting ◽  
Similar Elements

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.

Cu−Zr−Ti ternary bulk metallic glasses correlated with (L → Cu8Zr3 + Cu10Zr7) univariant eutectic reaction

2008 ◽  
Vol 23 (5) ◽  
pp. 1249-1257 ◽  
Author(s):  
Chun-Li Dai ◽  
Jing-Wei Deng ◽  
Ze-Xiu Zhang ◽  
Jian Xu
Keyword(s):  
Glass Transition ◽  
Metallic Glasses ◽  
Eutectic Reaction ◽  
Glass Forming Ability ◽  
Compositional Dependence ◽  
Copper Mold ◽  
Glass Forming ◽  
Copper Mold Casting ◽  
Mold Casting ◽  
Ti Content

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.

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