Aluminum Bronze

[chuck1]

I need the compressive yield strength for C63020 nickel aluminum bronze bar in order to calculate bushing yield. Does anyone know where I can find this information? MIL-HDBK-5 and any of the websites give only tensile properties.
Also, is there any other way to calculate bushing yield strength without knowing Fcy?

 

[WKTaylor]

I think this C63020 material specs-out as AMS4590... one of the the hardest/strongest Al-Ni-Brnzs made. I think i=this is also "proprietary" material [patented].

You need to find a vendor for the material and get specs from them... or set-up a sample test program and develop Your own mechanical values. As best I can tell, this material has an FCy that is very close to the FTy. I looked for about 1-hour and found data on everything else but this one... but I did run across the UNS-Spec relationship. We [aircraft mfgrs] use very little of this material because it is expensive and scarce... AMS4640 is much more readily available and is "the established standard" ... although much lower in mechanical strength.

CAUTION: application [use] of bronze is critical: what works well without lubrication may not work as well with common lubrication... and Vice-versa.

STRUCTURAL BUSHING??? structural hole reinforcement, little/no relative motion, yery highly loaded, pressed or cold-worked into position, no lubrication required [except for assembly].

PLAIN BEARING?? hole reinforcement, pressed or swagged into position, small relative movements and low speeds, highly loaded, grease lubrication required. [IE: landing gear Joints]

JOURNAL BEARING?? large relative movements and high speeds, moderate loads, with forced-lubrication [oil] required. [IE: engines]

Other application?? such as a component within a roller or self-aligning bearing??

Regards, Wil Taylor

 

[chuck1]

Hi Will!
Thanks for the info. My problem is that I need a material that is equivalent to the British Spec DTD197. I had a couple of existing bushings (these are on Falcon aircraft, by the way) chemically analyzed. The result is that the chemical analysis showed that C63020 is the equivalent. My problem also is that I need to convince the FAA that the C63020 aluminum bronze is structurally equivalent to the DTD197. Since I'm looking at replacing a bunch of Hawker Siddeley bushings I would like to avoid having to destroy a sample of each part number (gets expensive).
Thanks again for responding to my query.
Chuck Stucke

 

[chuck1]

Will:
I screwed up, they're Hawkers not Falcons (too many projects in my pile).
Chuck

 

[WKTaylor]

Chuck... rock & hard-spot ideas...

Get the data sheets on this British alloy and compare it to the C63020 [AMS4590]. Compare Heat-treatments, hardness variations, etc...

Check "registries" for all copper alloys in the world that provide cross-references and "equivelence".

Conduct hardness testing on the samples and compare to the AMS4590 spec. If AMS4590 is equal or better present it as a suitable substitute to the manufacturer and/or FAA.

Find a vendor for the AMS4590... and "ask" them about the British spec matl.

ASM has a great reference book on copper & alloys of copper... perhaps this could provide insight.

http://www.asm-intl.org

Present info to FAA and OEM... and/or just contact the FAA or OEM materials folks RIGHT NOW: they may have "worked" this problem before!

Regards, Wil Taylor

 

[brin]

OK- can I add one? I'm working on a material substution from QQ-B-671a (class C- 1942) to C95500 per ASTM B148. In the original analysis for this part (bushing) they used Fcy=Fty=35Ksi. This is based on the assumption that compressive strength is equal or greater than tensile strength for metals (1948 Metals Handbook, pg 109).

I haven't seen compressive yield strength listed in any copper-base specifications, or in the 1998 version of the Metals Handbook. However, the North American Aviation Co. structures manual (1961) does list equal compressive and tensile yield strength for QQ-B-671 class 3 HT alumium bronze.

My question is- would the original assumption of compressive yield = tensile yield strength hold true for modern alloys? Or is there another reference that lists Fcy values for copper alloys?

thanks

 

[chuck1]

Thanks, Guys, for the info and thoughts.
I've decided to use C63000 nickel aluminum bronze per AMS 4640 Condition TQ50 in lieu of the C63020 per ASTM B150. I'm assuming that Fcy=Fty (68 ksi, obtained from ASM Metals Handbook, Vol 2). I hope to convince the FAA that the C63000 is as strong as, or stronger than, the DTD197A British Spec. I'm also including in my report a comparison of the bushing yield strength versus the fitting shear-out strength. So far, nothing has come back from the FAA.
I don't know if there's any reference that verifies that Fcy=Fty, but MIL-HDBK-5H, Para. 1.4.5.2 states “For wrought metals, it is common practice to assume that the ultimate compressive stress is equal to the ultimate tensile stress.” So, I'm assuming that the same holds true for yield stress.
Chuck