Formation of VKNA-4U powder alloy using the SPS technology with preliminary mechanical activation

• Published in: Metallurgist (New York) Vol. 68; no. 5; pp. 750 - 756
• Main Authors: Shevtsova, Liliya I., Esikov, Maksim A., Malikov, Vladimir N., Kuz’min, Ruslan I.
• Format: Journal Article
• Language: English
• Published: New York Springer US 01-09-2024; Springer Nature B.V
• Subjects: Activated sintering; Alloy powders; Bend strength; Characterization and Evaluation of Materials; Chemistry and Materials Science; Intermetallic compounds; Materials Science; Metallic Materials; Microhardness; Nickel aluminides; Room temperature; Spark plasma sintering; Technology assessment; Workpieces; Spark plasma sintering; Powders; Nickel aluminide; 621.762:669.2; Alloying; Structure; Mechanical activation; VKNA-4U alloy
• ISSN: 0026-0894; 1573-8892
• DOI: 10.1007/s11015-024-01781-8

The results of structural studies and assessment of the bending strength of a VKNA-4U alloy based on nickel aluminide are presented. It is for the first time that this alloy was produced by spark plasma sintering of mechanically activated powders of the starting components. The mechanical activation of the powders lasted for 1.5, 3.5, and 5 min. X‑ray diffraction analysis was performed to determine the optimal duration (3 min 30 sec) of mechanical activation for this alloy. To obtain a dense low-defect workpiece, the VKNA-4U alloy was sintered at a heating temperature of 1100 °C, a pressure of 40 MPa, and a holding time of 5 min. This material has higher ultimate bending strength at room temperature (
σ
bend
 = 1215 ± 65 MPa) than the strength of Ni
3
Al intermetallic compound produced in similar conditions and microhardness 690 ± 25 HV.