EFFECT OF HOT ISOSTATIC PRESSING ON MECHANICAL PROPERTIES OF Fe41Cr15Mo14C15B6Y2Co7 BMG

2006 ◽  
Vol 20 (25n27) ◽  
pp. 3617-3622 ◽  
Author(s):  
QINGJUN CHEN ◽  
DELIANG ZHANG ◽  
JUN SHEN ◽  
HONGBO FAN ◽  
JIANFEI SUN ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Room Temperature ◽  
Hot Isostatic Pressing ◽  
Supercooled Liquid ◽  
Copper Mold ◽  
Porosity Level ◽  
Phase Form ◽  
Copper Mold Casting ◽  
Mold Casting ◽  
Microstructure Examination

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.

Structure and mechanical properties of Al–Mg alloys produced by copper mold casting

2010 ◽  
Vol 504 ◽  
pp. S483-S486 ◽  
Author(s):  
S. Scudino ◽  
M. Sakaliyska ◽  
K.B. Surreddi ◽  
F. Ali ◽  
J. Eckert
Keyword(s):  
Mechanical Properties ◽  
Mg Alloys ◽  
Copper Mold ◽  
Copper Mold Casting ◽  
Mold Casting ◽  
Al Mg Alloys

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 Minor Addition of Noble Elements on Microstructure and Mechanical Properties of Ti-Based Bulk Metallic Glasses

2011 ◽  
Vol 148-149 ◽  
pp. 241-244 ◽  
Author(s):  
Feng Xiang Qin ◽  
Guo Qiang Xie ◽  
Zhen Hua Dan ◽  
Akihisa Inoue
Keyword(s):  
Mechanical Properties ◽  
Plastic Strain ◽  
Shear Band ◽  
Metallic Glasses ◽  
Bulk Metallic Glasses ◽  
High Strength ◽  
Copper Mold ◽  
Copper Mold Casting ◽  
Minor Addition ◽  
Mold Casting

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.

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.

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.

Effects of Direct Thermal Method Processing Parameters on Mechanical Properties of Semisolid A6061 Feedstock

2021 ◽  
Vol 18 (1) ◽  
Author(s):  
M. F. M. Tajudin ◽  
A. H. Ahmad ◽  
M. M. Rashidi
Keyword(s):  
Mechanical Properties ◽  
Tensile Strength ◽  
Room Temperature ◽  
Processing Parameters ◽  
Holding Time ◽  
Thermal Method ◽  
Pouring Temperature ◽  
Porosity Level ◽  
Experimental Works ◽  
Temperature Water

This paper highlights the effects of pouring temperature and holding time on the mechanical properties of aluminium 6061 semisolid feedstock billets. The semisolid metal feedstock billets were prepared by a direct thermal method (DTM), in which the molten metal was poured into a cylindrical copper mould with a different combination of pouring temperature and holding time before it was solidified in room temperature water. The results show that the sample with pouring temperature slightly above aluminium 6061 liquidus temperature has the lowest porosity, thereby the highest mechanical properties value. The sample with a pouring temperature of 660 °C and holding time of 60 s has the density, tensile strength and hardness properties of 2.701 g/cm3, 146.797 MPa, and 86.5 HV, respectively. Meanwhile, the sample at a pouring temperature of 640 °C and holding time of 20 s has density, tensile strength and hardness properties of 2.527 g/cm3, 65.39 MPa, and 71.79 HV, respectively. The density and fractography tests were conducted to confirm the existence of porosity within the samples. The results from these experimental works suggested that the mechanical properties of DTM semisolid feedstock billet merely depended on processing parameters, which influenced the porosity level within the feedstock billet, thus directly affected their mechanical properties.

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