Optimisation of high energy ball milling parameters to synthesize oxide dispersion strengthened Alloy 617 powder and its characterization

• Published in: Advanced powder technology : the international journal of the Society of Powder Technology, Japan Vol. 30; no. 10; pp. 2320 - 2329
• Main Authors: Sivakumar, M., Dasgupta, Arup, Ghosh, Chanchal, Sornadurai, D., Saroja, S.
• Format: Journal Article
• Language: English
• Published: Elsevier B.V 01.10.2019
• Subjects: High energy ball milling; Ni-base super alloy; Oxide dispersion strengthening and optimisation; Oxide dispersion strengthening and optimisation; Ni-base super alloy; High energy ball milling
• ISSN: 0921-8831; 1568-5527
• DOI: 10.1016/j.apt.2019.07.014

[Display omitted] •Optimization of high energy ball milling parameters to synthesize Alloy 617 ODS.•Calculation of energy transferred to the powder using collision model.•Uniform distribution of Y2O3 at 1000 rpm (∼0.4 kJ/g.hit) for 6 h milling duration.•Presence of fine dispersoid in nanocrystalline matrix at optimized condition. In the present work, ultra-fine powder of oxide dispersion strengthened Alloy 617 was synthesized by high energy ball milling. Milling parameters such as rpm and milling time were varied in the range of 500–2000 and 5–360 min, respectively. Energy applied to the powder in the milling process (Energy per unit mass per hit, Ec) was estimated using the collision model. Effect of milling parameters on the microstructure of powder and refinement of oxides was investigated using X-ray Diffraction (XRD), Scanning electron Microscopy (SEM), conventional Transmission Electron Microscopy (TEM) and High resolution Transmission Electron Microscopy (HRTEM). Desired convoluted lamellar structure with average particle size ∼33 μm was observed during milling at 1000 rpm (Ec ∼ 0.4 kJ/g.hit) for 6 h. TEM analysis of the powder showed the presence of fine oxide dispersoids in the size range 4–16 nm. HRTEM analysis substantiated the presence of fine dispersoids of size ∼4 nm and showed the presence of deformation twins in the matrix. The fine dispersoids in a nanocrystalline matrix is expected to provide superior creep strength to the material at high temperatures.