Volvo’s megacasting in practice: process, quality and material cycle

At Torslanda, a single aluminium casting replaces hundreds of stamped and welded components on the EX60. Peter Schüler, Megacasting Shop Manager, explains the physics, the process, and the industrial ambition behind Europe's most advanced high-pressure die-casting cell.

Volvo Cars is the first European OEM to deploy megacasting technology at production scale, and the first customer anywhere in the world for a machine of this particular size, shot weight, and cycle speed. Peter Schüler, Shop Manager for Megacasting at Torslanda, points at the finished part with the merited confidence of someone who spent two years willing it into existence. "After two years, this is the product for startup production."

From coils to casting: why Volvo's stamping era had to be overcome

To understand what megacasting represents, it is first necessary to understand what it replaces. The floor of the current Volvo XC60 is a mosaic of pressed steel components. Raw material arrives as coils, which are cut into blanks and formed into shape under successive press tools.

"On average, to provide a good part historically, we have three and a half press stamping until we get a part," Schüler explains. Each forming step requires tooling, transfer, intermediate storage and inspection before the next stage can begin. Multiple sub-assemblies are produced in isolation and then united in the body shop. "We'd clamp, weld, clamp, weld, clamp, weld." The result of this traditional approach is not simply a complex process. It is a process that, structurally, creates unwarranted delay.

Megacasting collapses this entirely. Where the XC60 requires dozens of pressed and welded components to form its underbody, the EX60's rear floor structure is a single aluminium casting. "So how much time do we save?", asks Schüler, rhetorically. "We go from months, to days."

That reduction is as strategic as it is operational. Fewer components mean fewer suppliers, fewer internal logistics flows, fewer inspection gates, and a fundamentally different set of capital requirements. The EX60 was, from the beginning, designed with this in mind. It is, as Schüler puts it, "designed and born electric" rather than adapted from a combustion architecture. Its floor, and the battery it houses, were conceived as a unified system from the first engineering drawing.

The physics of pouring metal at speed

Die casting at this scale is a materials science challenge as much as it is a mechanical one. Aluminium behaves in ways that punish inadequate tooling, particularly at the volumes and injection speeds that automotive production requires. Schüler is precise about the difficulties his team had to master before the machine could run reliably.

"The tricky thing is to move material from A to B. It is to be able to go from wide to small, or wide to small, which slows down the process. The tricky thing is also, that with materials being pressed, you end up with turbulence."

Turbulence in a die-casting shot means entrapped air. Entrapped air means porosity in the finished part. Porosity means scrapped structural castings and, at automotive volumes - unacceptable waste. Controlling the flow of 93 kilograms of liquid aluminium across the full geometry of a car underbody, ensuring it fills every feature of a die without introducing defects, requires simulation capability that Volvo built up during the early development phase of the programme.

Machine uptime as the key to consistent quality

Schüler outlined how the thermal process is precisely staged. "So we buy this material, the raw material. You see the elevator over there? It goes directly up to the melt chain. So in the tower, we tip the material and we start the burners - at 750°C we start to melt. It goes by gravity into a holding furnace.

"The whole purpose of the holding furnace is to make sure that we always can melt at the same pace that we need to shoot." From the holding furnace, material transfers to a dosing furnace matched to the shot rhythm of the press. "And from that point, we pour 93kg into a shot sleeve. By milliseconds, we inject it into the mould and then we start to cool."

Asked to summarise the operating temperatures across the process, Schüler is precise: "In terms of temperatures, again, we melt at about 700°C-750°C, we inject at 250°C, we trim at about 60°C, and we cool down to 30°C."

Consecutive shots are also a prerequisite for consistent quality. "Every time you cool down the die - you're starting from zero. Then you need to reheat the die, and after three shots, you have production parts again. So the availability in the machine is key to be able to achieve this." An idle machine, when restarted, produces non-conforming parts for its first few cycles. Machine uptime, here, is a quality metric as much as a productivity one.

A 93kg shot and a 43kg part: the material arithmetic

In megacasting, that trimmed material goes nowhere outside the plant. “This goes Aluminium into the bin and directly into the melt chain. It means that you now can understand the complexity reduction of the complete value chain.” When the collection bins are full, the elevator that feeds the melt tower is recharged from them.

“So we can utilise every single piece of this material that we have bought.” It is a closed internal loop, and the contrast with stamping is stark. In a conventional press shop, scrap metal leaves the plant, must be reprocessed externally, and returns as new coil at cost. Here, the circuit is short and fully internal.

The weight advantage of aluminium over steel is substantial. “Normally we say that this way of producing vehicle parts amounts to just half of the weight of doing it the traditional way. So we save 50% of the weight.” For a battery-electric vehicle where every kilogram saved extends driving range and reduces battery sizing requirements, this is not a marginal improvement. It is a structural advantage built into the production method from the outset.

This is an edited and abridged version of the article from ams – automotive manufacturing solutions. You can find the full article at ams – automotive manufacturing solutions online. Registration may be required.