scholarly journals Structural and Mechanical Characteristics of Cu50Zr43Al7 Bulk Metallic Glass Fabricated by Selective Laser Melting

Materials ◽  
2019 ◽  
Vol 12 (5) ◽  
pp. 775 ◽  
Author(s):  
Xiaoyang Lu ◽  
Mussokulov Nursulton ◽  
Yulei Du ◽  
Wenhe Liao
Keyword(s):  
Metallic Glass ◽  
Bulk Metallic Glass ◽  
Selective Laser Melting ◽  
Structural Relaxation ◽  
Mechanical Characteristics ◽  
X Ray Diffraction ◽  
Laser Melting ◽  
Scanning Calorimetry ◽  
Mold Casting ◽  
Induced Changes

In this work, the structural and mechanical characteristics of Cu50Zr43Al7 bulk metallic glass (BMG) fabricated by selective laser melting (SLM) are studied and the impacts from the SLM process are clarified. Cu50Zr43Al7 alloy specimens were manufactured by the SLM method from corresponding gas-atomized amorphous powders. The as-built specimens were examined in terms of phase structure, morphologies, thermal properties and mechanical behavior. The x-ray diffraction and differential scanning calorimetry results showed that structural relaxation and partial crystallization co-exist in the as-fabricated Cu50Zr43Al7 glassy samples. The nano- and micro- hardness and the elastic modulus of the SLM-fabricated Cu50Zr43Al7 BMG were higher than CuZrAl ternary BMGs with similar compositions prepared by conventional mold casting, which can be attributed to the structural relaxation in the former sample. However, the macro compressive strength of the SLM-fabricated Cu50Zr43Al7 BMG was only 1044 MPa mainly due to its porosity. This work suggests that the SLM process induced changes in structural and mechanical properties are significant and cannot be neglected in the fabrication of BMGs.

Rapid Solidification and Laser Cladding of Gas Atomized Ni-Nb-Sn Bulk Metallic Glass

2017 ◽  
Vol 899 ◽  
pp. 311-316 ◽  
Author(s):  
F.L. Catto ◽  
A.H.G. Gabriel ◽  
C. Bolfarini ◽  
Claudio Shyinti Kiminami ◽  
Conrado Ramos Moreira Afonso
Keyword(s):  
Metallic Glass ◽  
Bulk Metallic Glass ◽  
Laser Cladding ◽  
Vickers Microhardness ◽  
Steel Substrate ◽  
Spray Forming ◽  
Glassy Matrix ◽  
X Ray Diffraction ◽  
Scanning Calorimetry ◽  
Mold Casting

Glassy overspray powders of Ni59Nb35Sn6 (at%) bulk metallic glass (BMG) obtained by spray forming were used in order to produce coatings on AISI 1020 mild steel substrate by laser cladding of the pre-placed powders. Different laser parameters, resulting in a variation of the power density, PD (J/mm2), were tested with a Yb fiber laser (up to 500 W). Gas atomized powders, suction cast sample trough copper mold casting and the laser clad tracks were characterized by scanning electron microscopy (SEM), X-ray diffraction (XRD), differential scanning calorimetry (DSC) and coatings were subjected to measurements of Vickers microhardness. Atomized powder obtained showed no crystalline phases formation up to 425 μm, indicating good glass forming ability (GFA) of Ni59Nb35Sn6 (at%) alloy. Microstructure characterization confirmed maximum glassy dimension of tc =1mm for the Ni59Nb35Sn6 (at%). Laser cladding track showed nanocrystalline phases embedded in a glassy matrix with Vickers microhardness ranging from 336 to 1184 HV.

scholarly journals EFFECT OF STRUCTURAL RELAXATION ON THE DEFORMATION BEHAVIOR OF A Zr64.13Cu15.75Ni10.12Al10 BULK METALLIC GLASS UNDER NANOINDENTATION

2010 ◽  
Vol 24 (15n16) ◽  
pp. 2320-2325 ◽  
Author(s):  
JIANSHENG GU ◽  
BINGCHEN WEI ◽  
TAIHUA ZHANG ◽  
YIHUI FENG ◽  
YANPING HU ◽  
...  
Keyword(s):  
Metallic Glass ◽  
Bulk Metallic Glass ◽  
Structural Relaxation ◽  
Deformation Behavior ◽  
Isothermal Annealing ◽  
Flow Behavior ◽  
Thermal And Mechanical Properties ◽  
Scanning Calorimetry ◽  
Obvious Effect ◽  
Dsc Curves

Structural relaxation by isothermal annealing below the glass transition temperature is conducted on a Zr 64.13 Cu 15.75 Ni 10.12 Al 10 bulk metallic glass. The effect of structural relaxation on thermal and mechanical properties was investigated by differential scanning calorimetry and instrumented nanoindentation. The recovery of the enthalpy in the DSC curves indicates that thermally unstable defects were annihilated through structural relaxation. During nanoindentation, the structural relaxation did not have a significant influence on the serrated plastic flow behavior. However, Structural relaxation shows an obvious effect in increasing both the hardness and elastic modulus, which is attributed to the annihilation of thermally unstable defects that resulted from the relaxation.

In situ high-energy x-ray diffraction observation of structural evolution in a Ti-based bulk metallic glass upon heating

2010 ◽  
Vol 25 (12) ◽  
pp. 2271-2277 ◽  
Author(s):  
N. Zheng ◽  
G. Wang ◽  
L.C. Zhang ◽  
M. Calin ◽  
M. Stoica ◽  
...  
Keyword(s):  
Metallic Glass ◽  
Bulk Metallic Glass ◽  
Free Volume ◽  
Structural Relaxation ◽  
Structural Evolution ◽  
High Energy ◽  
Rapid Quenching ◽  
X Ray Diffraction ◽  
X Ray

The structural evolution of the Ti40Zr10Cu34Pd14Sn2 bulk metallic glass (BMG) upon was investigated by means of in situ high-energy x-ray diffraction. The position, width, and intensity of the first peak in diffraction patterns are fitted through Voigt function below 800 K. All the peak position, width, and intensity values show a nearly linear increase with the increasing temperature to the onset temperature of structural relaxation, Tr = 510 K. However, these values start to deviate from the linear behavior between Tr and Tg (the glass transition temperature). The changes in free volume and the coefficient of volume thermal expansion prove that the aforementioned phenomenon is closely related to the structural relaxation releasing excess free volume arrested during rapid quenching of the BMG. Above 800 K, three crystallization events are detected and the first exothermic event is due to the formation of metastable nanocrystals.

Preparation of Zr60Ni21Al19 bulk metallic glass and compression behavior under high pressure

2008 ◽  
Vol 23 (9) ◽  
pp. 2346-2349 ◽  
Author(s):  
G. Li ◽  
Q. Jing ◽  
T. Xu ◽  
L. Huang ◽  
R.P. Liu ◽  
...  
Keyword(s):  
High Pressure ◽  
Metallic Glass ◽  
Bulk Metallic Glass ◽  
High Strength ◽  
Amorphous Structure ◽  
X Ray Diffraction ◽  
Compression Behavior ◽  
Copper Mold Casting ◽  
Mold Casting ◽  
Diamond Anvil

Zr60Ni21Al19 metallic glass rod, with a diameter of 8 mm, is manufactured by copper mold casting. The as-cast bulk metallic glass (BMG) exhibits nearly zero plastic strain, but a high strength of 1.88 GPa. The compression behavior of this new zirconium-base ternary BMG under high pressure at ambient temperature in a diamond-anvil cell instrument has been unraveled using energy dispersive x-ray diffraction with a synchrotron radiation source. The investigation shows that the amorphous structure of Zr60Ni21Al19 is stable under pressures up to 24.5 GPa at room temperature. According to the Bridgman equation of state, the bulk modulus B0 = 96 GPa has been obtained.

scholarly journals Development of process parameters for selective laser melting of a Zr-based bulk metallic glass

2020 ◽  
Vol 33 ◽  
pp. 101124 ◽  
Author(s):  
Jithin James Marattukalam ◽  
Victor Pacheco ◽  
Dennis Karlsson ◽  
Lars Riekehr ◽  
Johan Lindwall ◽  
...  
Keyword(s):  
Metallic Glass ◽  
Bulk Metallic Glass ◽  
Selective Laser Melting ◽  
Process Parameters ◽  
Laser Melting

Fabrication of Fe-based bulk metallic glass by selective laser melting: A parameter study

2015 ◽  
Vol 86 ◽  
pp. 703-708 ◽  
Author(s):  
Hyo Yun Jung ◽  
Su Ji Choi ◽  
Konda G. Prashanth ◽  
Mihai Stoica ◽  
Sergio Scudino ◽  
...  
Keyword(s):  
Metallic Glass ◽  
Bulk Metallic Glass ◽  
Selective Laser Melting ◽  
Parameter Study ◽  
Laser Melting

Structural Relaxation and Crystallization in a Pd40Cu30Ni10P20 Bulk Metallic Glass

2003 ◽  
Vol 806 ◽  
Author(s):  
R. Raghavan ◽  
U. Ramamurty ◽  
J. Basu ◽  
S. Ranganathan ◽  
N. Nishiyama
Keyword(s):  
Differential Scanning Calorimetry ◽  
Glass Transition ◽  
Metallic Glass ◽  
Bulk Metallic Glass ◽  
Structural Relaxation ◽  
Short Range ◽  
Annealing Temperature ◽  
Scanning Calorimetry ◽  
Short Range Ordering ◽  
The Stability

ABSTRACTThe stability of a Pd40Cu30Ni10P20 bulk metallic glass (BMG) against structural relaxation is investigated by isothermal and isochronal annealing heat treatments below and above its glass transition temperature, Tg, for varying periods. Differential scanning calorimetry (DSC) of the annealed samples shows an excess endotherm at Tg, irrespective of the annealing temperature. This recovery peak evolves exponentially with annealing time and is due to the destruction of anneal-induced compositional short range ordering. The alloy exhibits a high resistance to crystallization on annealing below Tg and complex Pd- and Ni-phosphides evolve on annealing above Tg.

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