Tesla Innovation: Aluminum Alloys For Die Casting −
In somewhat recent patent filing, Tesla showed off its latest engineering marvels with advanced aluminum alloys, which are able to retain high-yield strength and conductivity while Tesla die-casts electric car parts. The inventors behind the patent include Charles Kuehmann, a former Apple employee who specialized in alloys, identified a problem and the patent is a result of them solving it, Sivanesh Palanivel, Paul Edwards, and Ethan Filip. The excerpt below from the patent explains further the details and the benefit provided:
“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 approximately 40% IACS. Conversely, the 100.1 aluminum alloy has a conductivity of greater than 50% IACS, but a yield strength of less than 50 MPa. 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.
“It may be desirable to produce cast aluminum alloys with high yield strength such that the alloys do not fail easily while also containing sufficient conductivity for various applications. The aluminum alloys may be used in different automotive parts, including rotors, stators, busbars, inverters, and other parts. Current cast alloys do not well serve these parts the application of the parts. There still remains a need to develop cast aluminum alloys with high strength, improved conductivity, and sufficient castability.”
In layman’s terms, this means that Tesla needs to create alloys that have both high-yield strength and conductivity while simultaneously maintaining resistance to hot tearing in order to properly function in die casting unit components. Got it? This is needed in scenarios such as the internal components of an EV, like a rotor or inverter, requiring high strength and high conductivity at the same time. Forging the alloys can’t be done due to the casting process required to form these EV parts.
Also noted in the patent, Tesla explains that its advanced aluminum alloys can be adjusted. The yield strength can be set to 90 MPa and the electrical conductivity can range from 40% International Annealed Copper Standard (IACS) to 60% IACS. For just a bit more technical jargon, here’s a closing line:
“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.”