Cartridge brass as casting alloy component

[wmitty]

Took a look at the copper zinc phase diagram to see where the 70/30 cu-zn alloy went to liquid phase … 1680 degrees F . Is anybody knowledgeable regarding the combining of 70/30 brass with another element which would reduce the melting temperature to a suitable level to allow casting and also retain the higher density of the brass ( specific gravity of 8.3) ? A ternary alloy is the correct name; I believe, for a three element alloy. Could tin or lead or possibly antimony be added to the molten brass to reduce the melting point of the resulting alloy a significant amount? If the metallurgical engineering majors view this as a question with an intuitively obvious answer I humbly apologize for my ignorance.

[john.k]

Lead will lower the MP,but weaken the alloy .......lead is often added to bearing alloys where high strength isnt needed .....adding zinc will also lower the MP ...you can add zinc until the brass is only 10% copper......I dont doubt all this can be found online,with authoritative data ...rather than relying on fading memory.

[243winxb]

Post #2 looks good. Just got to play till a lower pour temperature is found?

https://www.rotometals.com/babbitt-bearing-alloys/


Lubaloy is made from combining 91% copper, 8.5% zinc, and 0.5% tin. Proportional variances are utilized for application specific demands of each desired material component. The range of compositions can vary from around 81 to 95% copper, 3 to 18% zinc, and 0.5 to 2% tin. A common variation of the Lubaloy alloy type in Lubaloy X 425, with a composition of 88% copper, 10% zinc, and 2% tin.
https://en.m.wikipedia.org/wiki/Lubaloy_C41100

Looks like a high percent of tin would be needed to lower melt temperature? Lead should also?

Interesting question. Hope an expert replies.

[sqlbullet]

You are over 90% lead or tin before you begin to hit the temperatures you want. At that point it isn't brass anymore, but a lead or tin alloy with copper and zinc constituents.