Page 62 - SAEINDIA Magazine December 2020

LIGHTWEIGHT

Feature

TESLA CASTS A NEW STRATEGY FOR LIGHTWEIGHT

STRUCTURES

The EV maker boldly invests in the world’s largest aluminum die-casting machine
to manufacture entire rear underbody structures.

Aluminum is synonymous
with “weight-saving” in most
contemporary automotive-
engineering reference points. But
apart from a few applications – most
notably Ford’s F-Series pickups
– aluminum largely is deployed
where steel can be readily displaced
without performance loss or for
comparatively small components that
deliver comparatively small weight or
process savings.

Electric-vehicle maker Tesla is
readying the next step in aluminum
use, however – one that effectively
matches Ford’s “big gain” approach
by specifying a massive piece of
structural die-cast aluminum for
the rear underbody of the recently
launched Model Y crossover.
According to Tesla CEO Elon Musk,
this new aluminum application
represents a radical step for its design
and manufacturing advantages and IDRA Group’s OL 5500, one of the company’s new Giga Press lineup designed
to produce large aluminum die castings.
its lightweighting potential. Musk is
renowned for outsized promises, but in the case of the “The current version of Model Y has basically two
Model Y’s die-cast rear underbody, his enthusiasm for big high-pressure diecast [HPDC] aluminum castings
this advanced use of aluminum – cast by a house-sized that are joined and there’s still a bunch of other
“giga press” – is supported by manufacturing experts bits that are attached. Later this year,” he said on
who call it a game-changer. the podcast, “we’ll transition to the rear underbody
being a single-piece casting that also integrates the
“It’s definitely an all-new look at how to do things,” rear crash rails.
asserted Laurie Harbour, president at Harbour Results
Inc. manufacturing consultancy. “Elon Musk has always “It gets better,” he continued. “The current castings,
pressed his engineers to be creative.” because you’ve got to interface with so many
different things, we have to CNC-machine the
Reductions in – pretty much everything
interfaces and there’s a bunch of things that have
Musk spoke in detail about the new casting process in to be joined; they have datums on them and that
an episode of the “Third Row Tesla Podcast” in April and kind of thing. The single-piece casting has no CNC
made more than a passing mention of it in Tesla’s 1Q2020 machining – it doesn’t even have datums. It took us a
financial results call in early May. lot of iterations, by the way, to get there.”

60 DECEMBER 2020 MOBILITY ENGINEERING