Gigacasting: The Hottest Trend In Car Manufacturing

Gigacasting is all the rage
in automotive manufacturing circles. And while Tesla has
mainstreamed the term — involving enormous, high-pressure
aluminum die casting machines that punch out vehicle chassis and
bodies-in-white — the technology has largely caught on in
mainland China. Now other automakers, including Toyota, are eyeing
the process.

The rising adoption of
aluminum gigacasting modules and structural parts is primarily
driven by the need to prevent the continuous increase in vehicle
weight, enhance fuel efficiency, and accommodate the growing demand
for battery electric vehicles. Done correctly, gigacasting can
theoretically slash per-unit manufacturing costs by eliminating the
welding of dozens of body parts by casting one single module. But
much of the conversation ignores fundamental roadblocks in
implementing the technology.

These massive gigacastings
(also known as megacastings) carry huge initial startup costs, may
have distortion issues in the metal, alter collision-repair
capabilities, and require extensive end-of-line inspection
scanning. And that is only after ordering a custom-built gargantuan
piece of equipment, moving it into place, and figuring out how to
efficiently work the temperamental processes.

So why are established
industry automakers and suppliers still chasing these big dreams
that come with massive headwinds? Do casting experts have enough
technical solutions to known operational problems? And looking
downstream into the vehicle use-case, can ADAS systems prevent
enough crashes to make up for these unrepairable castings?

Simple answer: It’s not
about the components, it’s about the assembly plant. And it’s not
about material and methodology changes to the underbelly of
vehicles, but the creative processes themselves which are under
transformation. And it’s not about the exact factory
implementation, but how an entirely new workflow can be enabled for
improved productivity.

When looking at market
share of advanced steels, stampers of those components, and
conversion rates in adoption scenarios, S&P Global Mobility
forecasts 15% to 20% of traditional body-in-white (BIW) stampings
in 2030 may be at risk from these gigacastings. Underbody
components typically comprise about 50% of a vehicle’s BIW shell,
and this soft underbelly is the target of gigacasting’s focus.

Expertise within suppliers,
factory designs, and vehicle configurations are all changing. As a
result, the era of transportation is approaching a disruption to
the auto industry’s backbone: the assembly line.

The assembly line process
as we know it stood for 110 years as the uncontested champion of
high-volume manufacturing. Components could be sub-assembled
offline, lasers might scan each part for dimensional accuracy, and
a bolt might even hold all the measurement data from rigorous
testing of a powertrain. But the assembly line itself evolved to
absorb these improvements. No revolution to assembly efficiency
stood to threaten the linear model — until now. Robotics,
automation, industry 4.0, and blockchain all have impacts on the
efficiency, cadence, and support networks of modern assembly
plants.

OEMs are looking towards
gigacasting not as a component piece, but as a change to how their
entire world functions. The reconfiguration of the dance played
behind factory walls will forever change economies within
automotive. Whether corner castings or single piece, whether
gigacast or gigapress, a change to how vehicles come together is
upon the industry. Nodal construction will replace linear,
bottlenecks will arise and dissolve, and something altogether new
will be born.

Source: S&P Global
Mobility

Gigacasting and
mainland China

The rise of aluminum
gigacasting in mainland China’s automotive sector, especially for
new energy vehicles (NEVs), is driven by weight reduction and
efficiency needs. Deciding between outsourced supply chains and
in-house production raises sustainability and cost concerns.

According to S&P Global
Mobility, production of electric light vehicles in mainland China
is expected to reach a total of 19 million units annually by 2030
— firmly establishing the country as a global leader in the EV
sector. Now, China looks to exert a substantial influence in
gigacasting globally.

Doing this will empower
mainland China EV manufacturers to adopt more aluminum material for
car-body fabrication and enhance its affordability. Consequently,
it can stimulate further growth within the EV market throughout the
region.

A recent major shift toward
aluminum gigacasting modules and structural parts has been seen
with NIO’s ET5 and Geely’s Zeekr 009 — both featuring
single-piece aluminum gigacasting rear floors. Meanwhile, Xpeng’s
G6 featured not only an aluminum megacasted single-piece front
compartment, inclusive of front shock towers and side members, but
also a single-piece rear floor. These two modules were separately
cast using two sets of LK Group’s 7,000-ton press force megacasting
machines.

Unlike Tesla’s gigacasting
production model – characterized by an in-house approach involving
substantial greenfield investments in gigacasting facilities
adjacent to the final assembly workshop — these automakers
outsourced gigacasting to tier 1 suppliers, sparking new
collaborations. This shift holds the promise of reaping benefits by
distributing responsibility between OEMs and tier 1 suppliers to
jointly develop technology while also mitigating the risks
associated with substantial upfront investments and potential
sensitive patent infringements. That said, challenges like machine
availability and technical disputes remain, which could snarl
future collaborations.

In the mainland Chinese
model, behind the scenes, extensive preparations integrate these
substantial outsourced modules from gigacasting into the body
assembly line. Over the last several months, several collaborations
were announced — including partnerships between Seres and
Wencan, Human Horizon EV and Tuopu, and Li Auto with an undisclosed
tier 1 supplier, among others.

The growing popularity of
the outsourced approach to gigacasting is also evident, as it
allows automakers to bypass the substantial upfront investments
required to construct their own gigacasting facilities.

A costly
gamble?

The cost-benefit analysis
of gigacasting should be based on achieving a good-enough
first-pass yield rate and maintaining a sufficient, yet not
excessive, number of orders for the same part. When comparing
gigacasting to conventional steel stamping or aluminum-stitching,
S&P Global Mobility nonetheless assesses the unit price for a
single-piece, gigacasted aluminum rear floor to be valid.

To streamline the
production chain and enhance production efficiency, tier 1
gigacasting suppliers have the potential to consolidate orders from
original equipment manufacturers (OEMs), thereby avoiding redundant
investments in gigacasting machinery. However, the downtime to
switch tooling on a gigacasting machine, which often weighs several
tons, can range from hours to days — inevitably reducing the
utilization rate and productivity.

Based on our previous
analysis of a typical 6,000T press force megacasting machine for
rear floor module fabrication, its maximum annual capacity is
estimated at 100,000 to 150,000 pieces, with cycle time of 120 to
150 seconds per piece, operating 16-20 hours a day for up to 300
working days a year, assuming a 90% yield rate. Frequent tooling
changes for different parts on the same gigacasting machine would
further reduce these output figures.

For a specific example,
Tesla’s Gigafactory in Shanghai Lingang is equipped with three or
four sets of IDRA’s gigapress units, specifically dedicated to
casting the one-piece rear floor for the Model Y. The maximum
production capacity for this model is estimated to reach up to
600,000 units per year, considering the scale of the gigapress
units.

A schematic of a Tesla
Model 3 (left) and Model Y body-in-white, comparing traditional vs.
gigacast assembly. The Model 3 comprises 171 metal pieces, whereas
the new gigacast Model Y rear structure requires just two pieces of
metal and 1,600 fewer welds.

Image source: Tesla

However, Tesla opted not to
utilize gigapress technology for the all-new Model 3s produced in
China, which was unveiled in August. Contrary to previous reports,
this model did not feature a one-piece aluminum rear floor, nor did
it incorporate a larger single-piece gigacasted underbody.

As such, we assert that
only a substantial number of gigacasting machines can effectively
sustain the outsourced gigacasting supply chain. Why is that?
Considering the maximum output volume is restricted to 150,000
pieces per year, it is evident that the existing capacity cannot
support an additional program for Model 3 volumes. The mega-casting
stands are fully occupied, and there are no available land
resources or plans for further investment to expand the in-house
capacity at Tesla’s Lingang plant, at least as of now.

Roadblocks to
gigacasting

How can OEMs and suppliers
integrate gigacasting technology with traditional body shop
processes? As Elon Musk has noted, it’s more complicated to make
the ‘machine that makes the machine’ than the end product
itself.

The production of a
gigacasting machine entails an investment of several months,
dedicated to both manufacturing and meticulous fine tuning, until
the machine achieves a level of reliability and stability suitable
for consistent output. These processes are undeniably
labor-intensive and demand a substantial infusion of specialized
knowledge. Currently, there exists a handful of companies,
(including LK Group, Buhler, Yizumi, Haitan and UBE), capable of
manufacturing the gigacasting machine. Consequently, the newfound
capacity for gigacasting falls short of meeting the escalating
demand for electrified vehicles.

There also are issues with
production management on the plant floors. Megacasted single piece
machines present an opportunity for OEMs to significantly reduce
the presence of machines, robots, and manual labor in their
traditional car body plants. However, the implementation of two
distinct manufacturing systems — the traditional body shop
employing stamping and welding processes, and the gigacast model
featuring fewer machining processes but necessitating new conveyor
systems to handle substantial material volumes — represents a
pragmatic compromise at the current juncture.

Which then begs the
question of how to profitably renovate or rebuild existing
production lines to incorporate outsourced gigacasting components.
Such methods remain unproven and, as of now, unjustified. While
capable of fabricating a portion of the underbody structural
components, gigacasting does not preclude the necessity for all
stamping and welding processes in the body shop.

The application of press
force in megacasting machines has given rise to considerable
debate. Normal high-pressure die-casting of aluminum typically
involves press forces of less than 4,000 metric tons.

However, Tesla raised the
ante with its groundbreaking innovation in 2019 to use gigacasting
to fabricate the rear floor section of the Model Y — using
between 6,000 and 9,000 metric tons of force. Tesla also is
reportedly close to being able to die cast nearly all of the
underbody of an electric vehicle in one piece.

Chinese OEMs are now
diligently striving to replicate Tesla’s success with gigacasting
machines featuring increasingly higher press forces; there are
reports of even more formidable 12,000 and 16,000 metric ton
machines.

While megacasting the body
section may not yield immediate profitability, there is a
collective determination within the industry to remain committed
until the revolutionary future arrives. While the use of
megacasting to produce body parts may require a long-term path to
profitable operation, the industry is committed to developing this
technology because it has the potential to rethink traditional
supply chains and production.

Nevertheless, S&P
Global Mobility sees numerous obstacles ahead, including challenges
related to the quantity of gigacasting machines, new issues arising
in plant floor management, the need to explore alternative
technical solutions and more.

Suppliers and OEMs should
consider these impediments when evaluating the strategic horizon
aligned with these casting questions.

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This article was published by S&P Global Mobility and not by S&P Global Ratings, which is a separately managed division of S&P Global.