Microstructure and mechanical properties of nickel strengthened by Y2O3 through rock-milling and spark plasma sintering

Microstructural evolution of a Y2O3 network reinforced Ni–Co based superalloy fabricated by spark plasma sintering

The invention provides alloy powder and a preparation method thereof. The preparation method of the alloy powder comprises the following steps that complexing is carried out, wherein alloy components and citric acid are subjected to complexing in a solution, and a complexing solution is formed; gel forming is carried out, wherein polyethylene glycol is added into the complexing solution to form gel; drying is carried out, wherein the gel is subjected to drying treatment to obtain dried gel; and the dried gel is subjected to calcining treatment, reducing treatment and crushing treatment to obtain the alloy powder. The alloy powder and the preparation method thereof have the beneficial effects of being simple in process and capable of achieving precise matching and have large advantages on uniformity and economical efficiency; then, the obtained powder is subjected to short-time ball grinding on the basis of a sol-gel method, alloy elements can be subjected to solid solution better, and powder particles are smaller; compared with a traditional MA method, the alloy powder is closer to a spherical shape; and compared with a method of preparing prealloy powder through the general sol-gel method and then carrying out ball grinding, the particle size has a certain advantage.

Alloy powder and preparation method thereof

Department of Metallurgical Engineering PSG College of Technology Coimbatore – 641 004, Tamil Nadu, IndiaPresent work involves preparation of nano sized yttria dispersed nickel-based superalloy by mechanical alloying (MA) in a planetary ball mill and optimization of process parameters. Nanocrystalline (NC) yttria was synthesized using a simple and economical sol-gel route. Elemental powders of composition Ni-20Cr-3Fe-0.5Ti-0.3Al-0.6Y2O3 wt% were mechanically alloyed at various milling times (5–40 h) in dry milling. Purity of the alloy and phase evolution was characterized by XRD. The alloying behaviour, particle size, particle shape and compositional analysis were done by SEM/EDAX. TEM of MA powders showed grain size in the micrometer range. The powders were consolidated by spark plasma sintering at temperatures from 1173–1373 K and microhardness measurements were also done. The sample sintered at 1173 K had the highest hardness; higher than that reported in the literature.

Monika Mohan

Papers

Yttria Dispersion Strengthened Nickel-based Superalloy by Mechanical Alloying