Aluminum Engine Block Casting Improved

Although a considerable amount of attention—rightly—is being paid to aluminum and its extensive application for closure panels (rightly because this clearly signals a shift in the way that trucks and cars are going to be built, more multi-material centric, so people in the industry need to be aware of it and the ramifications it has on design, engineering and production), for the past several years, aluminum has become more extensively used in powertrain, for engine blocks, in particular.

As these engines have received increased attention because there is a need to make them small and light, there is also an increased complexity in detail.

Which can make casting the blocks somewhat more tricky.

This came to our attention when we learned that Trimet, one of the leading aluminum casting producers in Europe, has switched over its lines to the use of a lubricant from Henkel Loctite Corporation (Henkel.com), Bonderite.

While this might not seem like a particularly big deal, apparently the shift has resulted in a cycle time reduction of 5%, which is considerable when you’re having to make more cast blocks.

One of the primary uses of Bonderite is to allow the cast block to be more readily removed from the mold. But Trimet engineers have found another benefit. The previously used lubricant had more organic constituents than the L-CA CP 791 they’re now using. During the hardening after casting (which is performed at approximately 700° C), the organics would burn off, leaving micro-scopic voids on the surfaces of the piston and cylinder cavities. The Bonderite doesn’t have the same results, as there is less gas generated.