Effect of Combined Ion-Plasma Thermocyclic Nitriding and Magnetic Abrasive Treatment on the Fatigue Resistance of the EK61 Alloy

• Published in: Strength of materials Vol. 55; no. 3; pp. 544 - 551
• Main Authors: Nalimov, Yu. S., Maiboroda, V. S., Rutkovskyi, A. V., Kononuchenko, O. V.
• Format: Journal Article
• Language: English
• Published: New York Springer US 01-05-2023; Springer; Springer Nature B.V
• Subjects: Abrasion resistance; Alloys; Characterization and Evaluation of Materials; Chemistry and Materials Science; Classical Mechanics; Comparative analysis; Fatigue strength; Fatigue tests; Hardness; Materials Science; Metal fatigue; Microhardness; Nickel base alloys; Nitriding; Plasma; Solid Mechanics; Specialty metals industry; Superalloys; Surface layers; magnetic abrasive treatment; EK61 alloy; ion-plasma thermocyclic nitriding; fatigue resistance; endurance limit; microhardness; combined treatment technology
• ISSN: 0039-2316; 1573-9325
• DOI: 10.1007/s11223-023-00547-y

Improving the fatigue resistance characteristics of parts subjected to alternating loads is an urgent problem that can be solved in various ways. One promising way is using various technological methods and their combination in the finishing operations of manufacturing parts. This study investigates the impact of the complex finishing of the EC61 alloy, consisting of a combination of ion-plasma thermocyclic nitriding and magnetic abrasive treatment, on fatigue resistance. The effect of the combined technological treatment of specimens was evaluated during comparative fatigue tests of treated specimens and specimens in the original state. The test results showed that the endurance limit of the untreated specimens based on 10
7
cycles was 400 MPa, and that of the specimens after combined treatment was 475 MPa, i.e., 19% higher than that of the specimens in the original state. The changes that occurred in the surface layer of the material after the combined treatment showed an increase in microhardness with the depth of the surface layer of the specimen. Thus, the microhardness value of the specimen surface after combined technological treatment is 53% higher than that of the untreated specimens, and the depth of the hardened layer is 0.09 mm. Thus, as a result of combined technological treatment using ion-plasma thermocyclic nitriding and magnetic abrasive treatment, a hardened layer with a depth of 0.09 mm was formed on the surface of the specimens, which increases the endurance limit of these specimens to 475 MPa. The work is a continuation of a series of studies of the impact of various technological treatments that cause changes in the surface layer of the material and, as a result, the fatigue resistance characteristics. A comparison of ion-plasma thermocyclic nitriding technologies and their influence on the characteristics of the surface layer and fatigue resistance of EC61 alloy specimens showed that both technologies strengthen the material’s surface layer, yielding different endurance limit values.