Wear between steels and an Aluminum Bronze 1

[twowaymonologue]

Hello, I'm a metallurgist for an Aluminum Bronze foundry. I have a customer asking a question relating to wear resistance between two steels (60 HRC) and between a steel and an alloy that we produce (basically UNS C95400 aluminum bronze). His question is as follows:

"Some years ago, we used a C95400 in bushing applications, however for economical situation we changed material in bushing to AISI C1144 (60 HRC), but we noticed an excessive wear combined with deformation.

We need to return C95400 or another recommendation if were possible …
For this, we some need technical information about wearing between materials (PIN: 8620(60 HRC) vs C95400 and C1144), the idea is to present a document with comparison that explain why is bad to use two materials with same superficial hardness (steels) in this case ASIS C1144 and AISI 8620)."

I am new to this position and have virtually no experience with wear. Can anyone offer me some insight?

Thanks much.

 

[Metalhead97]

ttwowaymonologue,

When testing is carried out in air, the oxides that form on the surface play important roles. The superficial hardness of the wear couple dictates the real contact area and the extent of plastic contact (the plasticity index). The real contact area controls how much force can be transmitted between the surfaces. The greater the amount of plasticity at the surface the more broken-up the native oxide film becomes. The nature of the tribolayer that forms between two contacting also affects the wear resistance. When testing is carried out in air, the oxides that form on the surface play important roles. See below how the Al-rich native oxide film helps form a barrier between the two surfaces.

http://www.copperinfo.co.uk/alloys/bronze/downloads/pub-126-al-bronze-wear-resistance.pdf

MH

http://www.linkedin.com/pub/luke-autry/1b/510/566

 

[twowaymonologue]

This was the one of the most helpful comments/papers I've ever had the pleasure of reading. Thank you so much, you've made everything quite clear!!