Apple's 3D printing technology will change the mobile phone industry's attitude towards "titanium".
Before we knew it, Apple has accomplished another significant feat.
Some time ago, Apple voluntarily "unveiled" that it has adopted a brand - new "titanium printing" process for products with titanium frames such as the Apple Watch Ultra 3. It even released a dedicated promotional video for this process after a long absence.
Image source: Lei Technology
Judging from the "direct impact" of this promotion, this process upgrade seems to be somewhat of a "failure". After all, the vast majority of Apple Watch Ultra users are not even aware that Apple has switched to a new manufacturing process, let alone experience the "technological improvement" behind the process upgrade.
However, in the view of Lei Technology, this kind of process improvement that "users can't tell the difference" actually proves the success of Apple's titanium printing process. It can maintain the same product performance with lower manufacturing costs, double the yield rate, and significantly reduce raw material waste. I believe friends with machining experience can understand what a huge achievement this is.
So, what exactly is this titanium manufacturing process called "3D printing"?
Completely Different from 3D Printing on the Market
If we place Apple's "titanium printing" promoted this time into the entire 3D printing system, it does belong to the category of additive manufacturing. However, the technology Apple uses is completely different from what the public understands as 3D printing.
Generally speaking, there are two common 3D printing technologies: Fused Deposition Modeling (FDM) and Stereolithography (SLA). These two printing technologies are very easy to distinguish. The consumable for the former is rolls of "plastic" strips (such as PLA), which are solidified through "heating and then cooling the consumable". The consumable for the latter is a special photosensitive resin liquid, and the light head irradiates and solidifies it with light of a specific wavelength (usually UV) at a specific position, thus stacking the model layer by layer.
Image source: Formlabs
Compared with the FDM solution, the advantages of stereolithography are obvious. The details of the model "pulled out" by the SLA solution far exceed those of the FDM process. However, no matter how "metal - like" the formed quality of the stereolithography model looks, it is ultimately a polymer structure, which has natural shortcomings in terms of strength, high - temperature resistance, and corrosion resistance. It can be used for testing the shape and verifying the assembly, but cannot be used for manufacturing mobile phone or watch casings.
Speaking of Apple, the Selective Laser Melting (SLM) process used by Apple this time, although it seems a bit similar to stereolithography, has significant differences in core technology:
Image source: Apple
The core of the Selective Laser Melting process is to melt and stack metal powder under laser energy to form a shape. Compared with SLA, the raw material for SLM is not resin liquid, but titanium metal powder on the scale of dozens of microns. The energy source is not ultraviolet light, but multiple high - energy lasers. And the final product is not a plastic model, but a metal structure that can be processed.
According to Apple's introduction, they have limited the diameter of the titanium powder raw material to ensure that the thickness of each layer is controlled at 60 microns during printing. The simultaneous printing method of the multi - laser array also enables the titanium powder raw material to form a continuous and dense metal structure.
Nevertheless, the "printing" in metal additive manufacturing is just the beginning. There are still a small number of pores and stresses inside the printed titanium structural parts. They need to be densified through hot isostatic pressing to make the internal structure close to that of a forged part. The surface is also difficult to form in one go and requires subsequent CNC finishing and polishing.
Does the Selective Laser Melting Process Usher in the "Titanium" Era?
From Apple's process, the Selective Laser Melting process is not a technology that allows products to be used right after printing. The formed titanium structural parts still have to go through processes such as hot isostatic pressing, CNC finishing, and polishing. Since the Selective Laser Melting process is so complex, why does Apple directly use it for production? (According to Apple, all Apple Watch Ultra 3 and titanium - cased S11 watch casings this year are manufactured using the 3D printing process)
The reason is actually very simple. The Selective Laser Melting process can significantly reduce material waste during the production process and improve the yield rate at the same time.
Traditional titanium processing relies on forging to form parts, and it must start by cutting from a billet much larger than the finished product. Titanium metal itself is difficult to cut and has poor thermal conductivity. Once the structure is complex, the yield rate of processing will "plummet". In fact, the uncontrollable processing cost accounts for the majority of the high price of digital products made of titanium.
Image source: Apple
The Selective Laser Melting process doesn't have such problems. Unlike traditional metal processing technologies that require an intermediate stage, the Selective Laser Melting process completes the formation of most of the volume during the printing stage, greatly improving the material utilization rate. According to the figures provided by Apple, the Selective Laser Melting technology can save 50% of raw materials. "This means that you can now manufacture two watches with the materials previously required for one watch." According to Apple's estimate, thanks to this new process, more than 400 tons of titanium raw materials have been saved this year alone.
In addition to saving raw materials, the Selective Laser Melting technology can also significantly improve the yield rate of titanium part processing. Since the main structure is completed during the printing stage, the subsequent CNC only needs to be responsible for accuracy and surface quality, rather than large - scale material removal. Therefore, the processing risk also decreases accordingly.
Moreover, the Selective Laser Melting technology also brings a degree of design freedom unimaginable with traditional processes.
Image source: Apple
Take the Apple Watch Ultra 3, which Apple emphasized in its introduction this time, as an example. Complex curved surfaces are extremely difficult to process in the CNC system. Multiple tool changes may be required when necessary. The ultra - small volume of smartwatches also limits the internal machining tool paths, and customized tool heads may be required when necessary. However, the application of the Selective Laser Melting process eliminates the constraints on design from an engineering perspective, making special structures that were previously impossible to achieve due to processing accuracy and cost a reality.
Therefore, in the view of Lei Technology, if the Chinese smartphone industry hopes to keep up with the "titanium era" initiated by Apple in terms of materials, rather than just staying at the "titanium - colored" color scheme, it must follow up with the Selective Laser Melting process or the laser sintering process and handle new materials in a new way.
Can Domestic Mobile Phones Use the Selective Laser Melting Process?
However, problems also arise. Since this is a key process in the "titanium era", why haven't domestic mobile phone brands followed up earlier?
As for whether domestic brands have the ability to implement the Selective Laser Melting process, the answer is definitely yes. After all, the Selective Laser Melting process is also a type of metal additive manufacturing. And the domestic additive manufacturing industry chain is extremely complete: from titanium powder atomization equipment to Selective Laser Melting forming machines, and then to subsequent five - axis CNC and automatic detection, the entire processing process has the ability for large - scale production. In other words, domestic manufacturers fully have the "industrial foundation" to produce titanium middle frames using the Selective Laser Melting process, and there are no technical barriers.
For domestic brands, the real difficulty of the Selective Laser Melting process lies in the mass - production system, rather than the technology itself.
For Apple, it's no problem to sell tens of millions of smartwatches for a single model. However, compared with Apple's product rhythm of no more than 5 mobile phone models a year, Android flagship phones are updated quickly, have a large number of SKUs, and are manufactured by decentralized OEMs. The products that can use the Selective Laser Melting process are quite limited. If the production scheduling is insufficient, the manufacturing cost will inevitably get out of control, and the manufacturing cost - effectiveness will be lower than that of forging or even CNC machining.
Image source: Xiaomi
Secondly, there is extremely fierce "resource competition" inside Android flagship phones. Functions such as imaging, hinges, and fast battery charging are all competing for the budget. Compared with upgrades that can directly change the user experience, the value of the titanium middle frame is quite limited. It's undeniable that in addition to being used to print titanium middle frames, the Selective Laser Melting process can also be used to manufacture key hinge parts of foldable mobile phones. However, the production volume of hinge parts is still far from enough to cover the cost of the Selective Laser Melting process.
However, the Selective Laser Melting process is also a technological route worth developing for domestic mobile phone brands aiming to enter the high - end market. After all, the Selective Laser Melting process doesn't have the limitations of forging and CNC machining and has stronger versatility. It can be used to make watch casings, lens rings, screen hinges, and even larger - volume parts. In the view of Lei Technology, the Selective Laser Melting process is not an unrealistic fantasy for domestic brands.
Where Will Apple Lead the Revolution in Body Materials?
Let's get back to Apple. Although in Apple's latest - season iPhones, only the iPhone Air, a "non - regular model", still retains the titanium middle frame. And the reason why the iPhone Air continues to use the titanium middle frame is that this phone was developed during the same period as the iPhone 16. But it's certain that Apple's pursuit of titanium middle frames, or more broadly, of titanium metal, will definitely not stop at the iPhone Air.
As we all know, products such as the Apple Watch and iPad have always been Apple's "testing grounds", where new technologies for future iPhones are "tested on real devices". Even from an engineering perspective, the future "foldable iPhone" will definitely use titanium metal to ensure the strength of the body and the hinge.
Image source: Lei Technology
From this perspective and combined with the characteristics of the Selective Laser Melting process, Lei Technology believes that titanium metal will have more applications within Apple. However, compared with the more promotional use of titanium middle frames, future titanium metal may emphasize more on practical significance. For example, paired with recycled aluminum casings, titanium structural parts can be created at specific positions such as hinges, the middle of the frame, and USB - C to reinforce the overall structure or to manufacture special parts that are difficult to process with traditional processes.
As for whether the titanium middle frame will become popular again at that time, I can't draw a conclusion so early. Personally, I've always been fond of frames made of high - strength materials such as stainless steel and titanium. After the iPhone 17 Pro switched to an aluminum alloy frame, I also directly pointed out that "an aluminum frame is not as high - end and durable as a titanium frame".
However, if the aluminum alloy middle frame can be as durable as the titanium frame with the structural reinforcement of titanium parts, then at least for most rational consumers, the "debate between aluminum and titanium" will no longer be important.
This article is from "Lei Technology" and is published by 36Kr with authorization.