Hardening of copper surfaces by beryllium diffusion
by M. Britchi, M. Branzei, D. Gheorghe
International Journal of Materials and Product Technology (IJMPT), Vol. 17, No. 8, 2002

Abstract: The paper contains results concerning the hardening of copper surfaces by beryllium diffusion. The superficial alloy was obtained in a galvanic cell provided with beryllium anodes and copper plates or rods as cathodes. A molten salt electrolytic bath containing the LiF-KF-NaF ternary eutectic mixed with 25 mole % BeF₂ was employed. When the circuit of the galvanic cell is closed by immersing the electrodes into the molten bath, beryllium ions diffuse through the molten electrolyte towards the cathode where they are discharged by the electrons that come via the external circuit. The beryllium atoms diffuse into the copper surface at 700°C, the working temperature. The beryllium coating obtained is composed of different phases, determined by the working conditions time period, cathode current density and BeF₂ purity. These phases correspond respectively to ß-phase (Cu₂Be) and γ-phase (CuBe). The two phases have hardnesses higher than either copper or beryllium. The hardness is constant over the entire thickness of the layer containing the same phase, which means that a diffusion process with reaction took place. The hardness at the interface layer-copper substrate has variable values. This means that diffusion of the beryllium into the copper begins with the formation of a solid solution that ensures a perfect adherence between coating and substrate.

Online publication date: Wed, 02-Jul-2003

The full text of this article is only available to individual subscribers or to users at subscribing institutions.

 
Existing subscribers:
Go to Inderscience Online Journals to access the Full Text of this article.

Pay per view:
If you are not a subscriber and you just want to read the full contents of this article, buy online access here.

Complimentary Subscribers, Editors or Members of the Editorial Board of the International Journal of Materials and Product Technology (IJMPT):
Login with your Inderscience username and password:

Username:        Password:          Forgotten your password?

Want to subscribe?
A subscription gives you complete access to all articles in the current issue, as well as to all articles in the previous three years (where applicable). See our Orders page to subscribe.

If you still need assistance, please email subs@inderscience.com