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When I walked into Alloy Enterprises’ headquarters just outside Boston, I didn’t expect to be handed a piece of metal as light as a feather or to learn that it had once lived in a backyard carriage house during the early days of the company. But that’s exactly how my visit began: not in a sleek, corporate setting, but in a place still full of that industrial, tinkerer spirit.
Alloy calls its employees “Builders,” which captures the hands-on approach that defines the team. They’re not just building parts, they’re building a new way to make them.
The company started in February 2020, right at the beginning of the pandemic. One of the earliest bonding machines, the one that shipped Alloy’s first parts, actually ran in one of the founders’ backyards.
“We made small things very slowly to start, but with a foundation to scale,” said Co-founder and CEO Dr. Ali Forsyth, as she handed me a prototype from those early days. “It’s wild to think how far we’ve come; now we’re producing thousands of complex parts, shipping copper and aluminum cold plates, and solving thermal problems for data centers and defense systems. Now we’re here.”
Alloy Enterprises CEO Dr. Ali Forsyth and Vanesa Listek at the company’s Burlington, MA HQ. Image courtesy of 3DPrint.com.
Today, Alloy Enterprises focuses on a very specific but massively important challenge: thermal management. Basically, they make complex metal parts that help keep high-performance electronics cool. These parts, often called “cold plates” or “heat exchangers,” are filled with intricate internal channels that let cooling fluids flow through efficiently, removing heat from components such as AI processors, server components, laser systems, or advanced defense technologies.
And while their parts may look like blocks of metal, they’re anything but. Each part reflects a high level of engineering detail, built using a unique process developed in-house by Alloy, called Stack Forging.
Here’s where it gets interesting. Alloy Enterprises isn’t a 3D printing company, although it is often mistaken for one. Instead, they use a proprietary process called Stack Forging, which combines elements of traditional manufacturing, additive, and some clever engineering.
At its core, the process works by first using thin sheets of metal that are laser-cut into complex stencils, inhibited in certain areas, stacked, and then diffusion-bonded together under heat, pressure, and a controlled atmosphere. The result is a single block packed full of parts, which is then broken apart. The resulting parts are fully dense, and leak-proof a precisely engineered interior, all without the need for welding, brazing, or O-rings.
“It has the benefit of 3D printing,” explained Forsyth. “But without the powder, without the porosity, and with real production throughput. We took pieces of existing technology — laser cutting, diffusion bonding, and 3D slicing strategies — and combined them into something entirely new. That’s how we built Stack Forging.”
The workflow is precise and timed, like clockwork. Aluminum or copper coils are unspooled, cleaned, prepped, laser-cut layer by layer, and stacked in perfectly registered alignment, as demonstrated by Director of Part Production, Dave Tedder. An inhibition agent is applied where bonding is not desired, so the part can later be separated cleanly from its surrounding support metal.
“The bonding cycle takes a few hours. But we’re not just making one part. We can build dozens, sometimes hundreds, at once, depending on the size. We’ve had builds with over 250 parts, and others with just one large component filling the whole volume,” noted Tedder. “We’ve designed the whole process to scale. That’s why we can get such high throughput without compromising on detail.”
Dave Tedder next to one of the machines at Alloy headquarters in Burlington, MA. Image courtesy of 3DPrint.com.
One of the biggest takeaways from the visit was getting to see copper production launch the very week I was there.
“It’s been four months of development to get it right, so we’ve had it in beta, but June was the formal launch,” stated Forsyth. “Copper offers superior thermal performance, and for some data center customers, it’s a non-negotiable due to chemical compatibility standards. With copper, performance just gets better, and we’ve now got the process dialed in.”
The company has also made a decisive strategic pivot. While early customers came from the automotive and heavy equipment sectors, Alloy now puts its full attention on thermal challenges in data centers, defense, photonics, and high-performance computing. They have even worked with major server OEMs, and their cold plates can reduce thermal resistance by 35% and pressure drop by up to five times compared to the next-best solution.
“This is where we’re winning. Startups need to find their niche and dominate it. For us, it’s thermal management — that’s where we’ve seen the clearest demand and where our technology delivers the biggest edge,” Forsyth outlined.
Alloy’s Stack Forging process builds fully dense metal components. Image courtesy of Alloy Enterprises.
If Alloy sounds like it’s selling machines, well, it’s not. The company is not offering “stack forgers in a box,” like Forsyth said. In fact, the machines stay in-house for now.
“This isn’t just a printer,” Tedder said simply. “It’s a whole facility. You’d need 10,000 square feet and a lot of expertise.”
And it shows. The factory buzzes with activity, but it’s not chaotic. The construct machines run “lights out” overnight, stacking and prepping sheets autonomously, he explains. Traceability is baked into everything: each part, each sheet, even each coil can be traced back to its origin.
Alloy Enterprises’ headquarters in Burlington, MA. Image courtesy of 3DPrint.com.
While touring the production floor, I came across a freshly bonded block weighing around 175 pounds that was cooling down. It would later be cleaned, leaving behind a fully dense copper part with microchannels finer than a strand of hair, Tedder pointed out.
“This is a mix of four complex engineering efforts: the material science, the hardware, the process, and the software that runs it all. They all had to evolve in sync,” said Forsyth, pointing toward the construct and bond machines. “From the way we cut and treat the sheets to how we bond them and inspect every layer, it all had to be designed together. None of this works if even one part falls behind.”
What stood out to me most, aside from the gorgeous copper components, was the way Alloy approaches sustainability. Metal powders used in 3D printing are expensive, hard to recycle, and incredibly carbon-intensive to produce. But Alloy’s process uses flat sheet feedstock, which is easy to reclaim and remelt.
“Both aluminum and copper retain value in scrap,” said Forsyth. “That’s part of what makes our process so efficient; it’s good for the planet and the bottom line. We designed Stack Forging with circularity in mind. Unlike metal powders, which are harder to produce and recycle, our sheet-based feedstock can be sent right back to the mill. That adds up quickly when you’re scaling.
“And beyond the process itself, the parts we make are helping our customers be more energy-efficient. High-performance cooling translates to real power savings, especially in data centers. We’ve run the numbers, and with the right thermal management in place, you could reduce data center energy consumption by more than 20%. That’s a huge deal not just for cost, but for emissions.”
Alloy Enterprises CEO Dr. Ali Forsyth. Image courtesy of 3DPrint.com.
Visiting Alloy Enterprises felt like stepping into part startup lab and part industrial powerhouse, but also grounded in stories of builders, backyard machines, and a five-year journey from Somerville to the heart of the thermal industry.
🏷️ p3d_feedAs Forsyth puts it, “We’re not here to chase every market. We’re here to make the one thing we do better than anyone else.”