Machining alloy 954 aluminum bronze

[Philrock]

I am going to bolt and dowel pin an alloy 954 aluminum bronze part to an AL 6061-T6511 part. I plan to bolt the parts together then match drill and ream for the dowel pins. Final reamed hole size is 5 mm. Thickness of aluminum bronze piece is 9 mm. I understand 954 aluminum bronze can be challenging to machine. A few questions:

What kind and size of drill bit should I use before reaming?

What kind of reamer should I use? Carbide? No. of flutes? Spiral flutes?

What speeds, feeds, and coolant should I use for both drilling and reaming?

 

[kenvlach]

I've machined very few bronzes, but decided to look this one up as I recalled most are easy to machine.

CDA 954 is relatively easy to machine (60% of CDA 360 free-machining brass) in either as-cast or TQ50 temper, whereas CDA 952 is only rated 20%, so maybe the latter was the origin of your info.

CDA 954 (Ampco C3, UNS C95400, 85Cu-4Fe-11Al) "is easily machined by all standard operations using high-strength tool steel or carbide cutters. Typical conditions using tool steel cutters: roughing speed 90 m/min (300 ft/min) at a feed of 0.3 mm/rev (0.011in/rev); finishing speed 290 m/min (950 ft/min) at a speed of 0.1 mm/rev (0.004 in/rev)"
-- Metals handbook vol. 2, 9th Edn. p. 433.

 

[EdDanzer]

We machine several parts from aluminum bronze (CA954) and use tools, feeds, and speeds similar to 4140 annealed. This material is has a tensile close to 100,000 psi.