Influence of mechanically milled powder and high pressure on spark plasma sintering of Mg–Cu–Gd metallic glasses

Metallic glass powder of the composition Al86Ni6Y4.5Co2La1.5was consolidated into 10 mm diameter samples by spark plasma sintering (SPS) at different temperatures under an applied pressure of 200 MPa or 600 MPa. The heating rate and isothermal holding time were fixed at 40°C/min and 2 min, respectively. Fully dense bulk metallic glasses (BMGs) free of particle-particle interface oxides and nano-crystallization were fabricated under 600 MPa. In contrast, residual oxides were detected at particle-particle interfaces (enriched in both Al and O) when fabricated under a pressure of 200 MPa, indicating the incomplete removal of the oxide surface layers during SPS at a low pressure. Transmission electron microscopy (TEM) revealed noticeable nano-crystallization of face-centered cubic (fcc) Al close to such interfaces. Applying a high pressure played a key role in facilitating the removal of the oxide surface layers and therefore full densification of the Al86Ni6Y4.5Co2La1.5metallic glass powder without nano-crystallization. It is proposed that applied high pressure, as an external force, assisted in the breakdown of surface oxide layers that enveloped the powder particles in the early stage of sintering. This, together with the electrical discharge during SPS, may have benefitted the viscous flow of metallic glasses during sintering.

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Processing of Hf based bulk metallic glasses through Spark Plasma Sintering (SPS) process

Journal of Alloys and Compounds ◽

10.1016/j.jallcom.2021.160057 ◽

2021 ◽

pp. 160057

Author(s):

N. Saijyothi ◽

D. Arvindha Babu ◽

B. Srinivasarao ◽

Bhaskar Majumdar

Keyword(s):

Spark Plasma Sintering ◽

Metallic Glasses ◽

Bulk Metallic Glasses ◽

Plasma Sintering ◽

Spark Plasma

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Production of Dispersion-Strengthened Cu-TiB2 Alloys by Ball-Milling and Spark-Plasma Sintering

Materials Science Forum ◽

10.4028/www.scientific.net/msf.534-536.1489 ◽

2007 ◽

Vol 534-536 ◽

pp. 1489-1492 ◽

Cited By ~ 1

Author(s):

Dae Hwan Kwon ◽

Jong Won Kum ◽

Thuy Dang Nguyen ◽

Dina V. Dudina ◽

Pyuck Pa Choi ◽

...

Keyword(s):

Electrical Conductivity ◽

Ball Milling ◽

Spark Plasma Sintering ◽

Ball Mill ◽

Milling Time ◽

Rotation Speed ◽

Sintering Temperature ◽

Milled Powder ◽

Plasma Sintering ◽

Spark Plasma

Dispersion-strengthened copper with TiB2 was produced by ball-milling and spark plasma sintering (SPS).Ball-milling was performed at a rotation speed of 300rpm for 30 and 60min in Ar atmosphere by using a planetary ball mill (AGO-2). Spark-plasma sintering was carried out at 650°C for 5min under vacuum after mechanical alloying. The hardness of the specimens sintered using powder ball milled for 60min at 300rpm increased from 16.0 to 61.8 HRB than that of specimen using powder mixed with a turbular mixer, while the electrical conductivity varied from 93.40% to 83.34%IACS. In the case of milled powder, hardness increased as milling time increased, while the electrical conductivity decreased. On the other hand, hardness decreased with increasing sintering temperature, but the electrical conductiviey increased slightly

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