Has anyone found an effective way to use infrared to measure the temperature of aluminum?

It is too bright for conventional infrared. I have heard that some systems use software to ignore the extraneous light.

If there are any deep narrow holes/crevices in the aluminum, those will provide an emissivity of near 1.0 due to the “cavity effect”. If the hole is small you need to be close enough so your measurement field of view limitations are not exceeded.

Another option is to put paint or tape of known emissivity on one area and shoot that.

Examining a low-emissivity aluminum surface directly will generally be the toughest and least accurate option. Characterize the emissivity by comparing contact measurements to your camera measurement. Properly accounting for reflected energy is important on low emissivity surfaces as well.

There's a new chip technology I'm going to try hopefully soon. Do a search on the thread; it's here somewhere.