Plasma Alloying and Spheroidization Process and Development

O'Dell, J. Scott; Schofield, E.; Mckechnie, Timothy N.; Fulmer, A.

doi:10.1361/10599490419946

Cited by 10 publications

(2 citation statements)

References 1 publication

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“…10 wt% W and 0.1 wt% C were added to reflect D-43 nominal levels, while 20 wt% W and 0.1 wt% C were added to form AS-30. All powder mixtures were spheroidized using the Powder Alloying and Spheroidization (PAS) process [ 31 ]. During PAS processing, powder feedstock is fed through a plasma flame, capable of reaching 10,000 K, where both spheroidization and alloying can occur depending on particle size, melting point, degree of contact between constituent particles, and residence time in the plasma flame.…”

Section: Methodsmentioning

confidence: 99%

Electron Beam Melting of Niobium Alloys from Blended Powders

et al. 2021

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Niobium-based tungsten alloys are desirable for high-temperature structural applications yet are restricted in practice by limited room-temperature ductility and fabricability. Powder bed fusion additive manufacturing is one technology that could be leveraged to process alloys with limited ductility, without the need for pre-alloying. A custom electron beam powder bed fusion machine was used to demonstrate the processability of blended Nb-1Zr, Nb-10W-1Zr-0.1C, and Nb-20W-1Zr-0.1C powders, with resulting solid optical densities of 99+%. Ultimately, post-processing heat treatments were required to increase tungsten diffusion in niobium, as well as to attain satisfactory mechanical properties.

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Section: Methodsmentioning

confidence: 99%

Electron Beam Melting of Niobium Alloys from Blended Powders

et al. 2021

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“…그러나 AlN은 스프레이 동안 대기 중의 산소와의 반응과 고온 노 출에 따른 상분해로 인하여 코팅층 형성이 거의 불가능 하다 13,14). 플라즈마 스프레이 공정을 이용하여 고열전도성 공정으로15,16) 제조하였다. 먼저 각각의 원료분말을 1:1로 측량하고 AlN 분말의 산화/분해를 방지하기 위하여 스테아린산을 이용하여 소수성 코팅을 실시하였으며, 인산 알루미늄을 분산제로 사용하여 증류수와 혼합하여 습식 볼 밀을 행하였다.…”

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Microstructural Evolution of Aluminum Nitride - Yttrium Aluminum Garnet Composite Coatings by Plasma Spraying from Different Feedstock Powders

소웅섭¹,

Baik²

2011

Korean. J. Mater. Res.

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A high thermal conductive AlN composite coating is attractive in thermal management applications. In this study, AlN-YAG composite coatings were manufactured by atmospheric plasma spraying from two different powders: spray-dried and plasma-treated. The mixture of both AlN and YAG was first mechanically alloyed and then spray-dried to obtain an agglomerated powder. The spray-dried powder was primarily spherical in shape and composed of an agglomerate of primary particles. The decomposition of AlN was pronounced at elevated temperatures due to the porous nature of the spray-dried powder, and was completely eliminated in nitrogen environment. A highly spherical, dense AlN-YAG composite powder was synthesized by plasma alloying and spheroidization (PAS) in an inert gas environment. The AlN-YAG coatings consisted of irregular-shaped, crystalline AlN particles embedded in amorphous YAG phase, indicating solid deposition of AlN and liquid deposition of YAG. The PAS-processed powder produced a lower-porosity and higher-hardness AlN-YAG coating due to a greater degree of melting in the plasma jet, compared to that of the spray-dried powder. The amorphization of the YAG matrix was evidence of melting degree of feedstock powder in flight because a fully molten YAG droplet formed an amorphous phase during splat quenching.

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