Tesla's superstar lead of materials engineering
Tesla's push to advance transportation technology comes on the heels of the company's ongoing curation of the superstar engineering teams. Together, they are literally inventing the advanced materials needed for their full suite of next-gen products.
Obviously, that's already an exceedingly-intimidating resumé, but Kuehmann is also the man behind these advanced new alloys.
Why new alloys are needed for next-gen transportation
The newly-released Tesla patent describes the problem Kuehmann and his team set out to solve:
"Commercial cast aluminum alloys fall into one of two categories -- either possessing high-yield strength or possessing high conductivity. For example, the A356 aluminum alloy has a yield strength of greater than 175 MPa, but has a conductivity of apporximately 40% IACS. Conversely, the 100.1 aluminum alloy has a conductivity of greater than 48% IACS, but a yield strecngth of less than 50MPa. For certain applications, for example, parts within an electric vehicle like a rotor or an inverter, both high strength and conductivity are desired. Further, because it is desired to form these electric-vehicle parts through a casting process, wrought alloys cannot be used. Rather, it is desirable to form the parts through a casting process, such that the parts may be cast quickly and reliably, such as through a low pressure and high velocity metal injection or a high pressure die casting process. After casting, suitable alloys must maintain their properties sufficiently for the necessary application. Poor castability of the alloy often results in observed hot tearing, and can cause fill issues which typically decreases the mechanical and electrical properties of the end cast part."
This means Tesla needs to manufacture alloys that have both high-yield strength and conductivy, while also maintaining resistance to hot tearing, to properly function in die casting unit components.
Further materials toward new alloys for electric cars
In the patent, Tesla further explains that its advanced aluminum alloys can be adjusted to offer a yield strength of 90 Mpa, and electrical conductivity that ranges from 40% IACS to 60% IACS.
Of course, Tesla also claims that its new alloys can still successfully perform die casting:
"In one embodiment, the alloy has the proper fluidity to ensure that the alloy wets the entire length of a mold and the mold is properly formed, and such that the alloy resists hot-tearing and retains the desired yield strength when the cast solidifies."
Clearly there is a treasure-trove of new and interesting engineering in the patent alone, which is worthwhile reading for every aspirational engineer (feel free to download!). But the applications of new alloys are the stuff of dreams, which is where the seemingly-endless advancements of Tesla intersect with lived reality: in the utopic possibilities of a new, sustainable future for transportation technology.