A 150 ton press could crack virtually any metal, the forces are incredible locally. More details are needed, pictures preferably. Two common methods of dealing with forming pressure are to first make sure there's enough material there to begin with, and if it's a formed part annealing before pressing can make all the difference.

I work at a machine shop that does several press fitted aluminum parts and the only way they work is if they're annealed before pressing.

If the part is not properly designed, cracking can happen if there are sharp corners. Do the dies have the right amount of draught and clearance? Also as the other reply made, the material should be annealed to remove stress. I'm sure you can adjust the pressure if 150 tons is too high.

No problems with this answer-

BUT if your process is an automated system using coiled aluminum sheared and fed into the press, you might try installing about two meters of ceramic faced infrared heaters (probably about 3) about 10, 15, and 20 cm above the flattened coil (closest nearest the shear point) to preheat it prior to stamping.

Just another suggestion if you are running a continuous batch process. Also- have the mounting heights adjustable in case things are getting too hot with those settings.

This is the only responsible answer the way I see it. How people can prescribe thermal treatments when the grade gage and degree of work is not known is frightening to me. "just add heat and ignore the temper". Uhh show me that in your quality system scope. Really folks, without knowing material gage or configuration of tool ( let alone lube issues!) you just opine to anneal? On what basis? Milo

Tou are absolutely right Milo.

What were we thinking? The OP gave us all the information. It's inexcusable.

I see that you join my opinion: people are NOT serious in giving counsel without even knowing what they write about. The quality of CR4 is unfortunately going down.

What is the specification heat treatable or non heat treatable, temper designation,bend radius, bend across radius or along, ?

Sounds like either a (1) material selection or material condition (temper) problem, (2) manufacturing problem (correct dies??) or a design problem in the part. (minimum bend radius for alloy being used??)

All of the aluminum manufactures provide product and data catalogs which detail the numbering systems for aluminum based on alloying materials, weld ability, heat treatment, standard tolerances, chemical compositions, mechanical properties, and nomenclature.

The first area I'd be looking at would be bend radii for the type or series of the material being used, (2024, 5052, 6061, 7075, material condition, (heat treatment) and material thickness, and lastly, the design and material specification of the part. (have these parts been successfully fabricated previously)???

Remove the fault?

Yeh, do it again properly!

Step outside your cast blinkered world and talk to this guy....

His family have been annealing metals for generations to avoid the very thing that seems to be plaguing you ...no fancy degrees, no privileged cast, no nonsense....

Just ask them and they'll tell you that you just can't anneal enough.

The answers are around you if you just care to look.

GA by the way mike k.

Is the part designed for the process ? Can you provide a drawing ? Material ? How you do the operation ?