| Autor: |
Фальченко, Ю. В., Петрушинець, Л. В., Мельніченко, Т. В., Новомлинець, О. О., Федорчук, В. Є. |
| Předmět: |
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| Zdroj: |
Metallophysics & Advanced Technologies / Metallofizika i Novejsie Tehnologii; Aug2022, Vol. 44 Issue 8, p1013-1023, 11p |
| Abstrakt: |
Investigations on vacuum diffusion welding of nichrome powder alloy Ni-20Cr--(3--4)Fe--(0.40--0.6)Al--(0.25--035)Ti--0.5Y (% wt.), are presented. As shown, welding nichrome alloy directly in the temperature range of 800-1100°C under vacuum of 1.33 10-3 Pa does not provide sound joints. As found, during nichrome alloy heating, oxidation of its contact surfaces takes place, which makes it more complicated to produce the welded joint. The possibility of protection of the alloy surfaces from oxidation by coating them with nickel is studied. Deposition of a nickel interlayer by EBPVD method in the form of 5-7 µm thick coating allows avoiding oxidation of the contact surfaces. The influence of heat treatment in vacuum on the coating chemical composition is investigated. As shown, annealing of the coated samples at T = 1100°C for 10 min. under vacuum of 1.33 10-3 Pa promotes enhancement of the diffusion processes between the base metal and deposited nickel layer and ensures equalizing of the chemical composition in the zone of contact of the coating and the alloy. As shown, the microstructure of the samples, produced in the following mode: T = 1200°C, P = 40 MPa, t = 20 min is characterized by absence of defects in the joint zone. Distribution of chemical elements in the welded joint is monotonic. Diffusion of elements from nichrome alloy into the nickel coating ensures formation of the diffusion zone, is similar, in its chemical composition to nichrome alloy. Mechanical properties of the welded joints are studied. As demonstrated, application of an intermediate nickel layer at vacuum diffusion welding of a nichrome powder alloy enables producing joints with the microhardness on the level of that of the base metal after annealing. [ABSTRACT FROM AUTHOR] |
| Databáze: |
Complementary Index |
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