A new type of 3D printing may bring it into the mainstream

一種新型3D打印可能會將該技術(shù)帶入主流

It is to the old version as the printing press is to the pen

這種技術(shù)之于舊版，就像印刷機之于筆

EARLY FORMS of additive manufacturing, or 3D printing as it is popularly called, began to emerge in the 1980s. But it took more than a decade for the technology to start taking off. Initially, it was used to make prototypes. Now, intricate components are routinely 3D-printed in plastic and metal, for use in products ranging from jet engines and robots to cars.

增材制造有個通俗的名字叫3D打印，它的早期形式始于上世紀80年代。但這項技術(shù)經(jīng)過十年多才真正起步。起初，它被用于制作原型機?，F(xiàn)在，人們已在常規(guī)化地使用3D打印制造復(fù)雜的塑料和金屬部件，用于噴氣發(fā)動機、機器人、汽車等各種產(chǎn)品。

Sales of 3D-printing services and machines grew by more than 17% in 2021, to reach around $15bn, according to preliminary estimates for a report by Wohlers Associates, a firm that tracks the industry. However, as useful as additive manufacturing has become, it struggles to compete on cost and speed with more established ways of making things, such as injecting molten plastic into moulds or stamping out metal parts with a giant press.

追蹤這一行業(yè)的公司W(wǎng)ohlers Associates在一份報告里初步估計，2021年3D打印服務(wù)和設(shè)備的銷售額增長了17%以上，達到150億美元左右。不過，盡管增材制造已變得很實用，但它在成本和速度方面仍難與更成熟的制造方式匹敵，比如注塑成型或是用巨型壓力機沖壓出金屬零件。

As a result, most manufacturers use 3D printers to produce low-volume, high-value parts. The extra time and expense this takes can be worth it for certain items. Making things additively produces objects layer by layer, so tricky internal structures can be incorporated more easily into a design. Shapes can also be optimised for strength and lightness, saving materials. But what if these advantages could be had at the speed and cost of conventional factory processes? A new form of additive manufacturing aims to do just that.

因此，大多數(shù)制造商用3D打印機來生產(chǎn)數(shù)量少、價值高的部件。對于某些部件來說，多花些時間和費用是值得的。增材制造是逐層生成物件的，所以就更容易將復(fù)雜的內(nèi)部結(jié)構(gòu)整合成一整個設(shè)計。還可以優(yōu)化形狀以滿足強度和輕巧度的要求，節(jié)省材料。但是，如果既能有這些優(yōu)勢，又能兼具傳統(tǒng)工廠加工的速度和成本呢？一種新型增材制造就是要做到這一點。

The origin of this process, trademarked “Area Printing”, goes back to 2009. That was when James DeMuth, having finished his master’s degree in mechanical engineering at Stanford University, started work at the National Ignition Facility, part of the American Department of Energy’s Lawrence Livermore National Laboratory (LLNL). This uses some of the world’s most powerful lasers to study nuclear fusion.

這項注冊名為“區(qū)域打印”的工藝可以追溯到2009年。當(dāng)時詹姆斯·德穆思（James DeMuth）在斯坦福大學(xué)獲得了機械工程碩士學(xué)位，開始為國家點火裝置（National Ignition Facility）工作，該裝置隸屬于美國能源部的勞倫斯利弗莫爾國家實驗室（Lawrence Livermore National Laboratory，LLNL）。它用世界上最強大的一些激光來研究核聚變。

One of the challenges Mr DeMuth was given was to find a way to use a highly specialised type of steel to manufacture a 12-metre wide fusion chamber containing many complex features. He considered a form of 3D printing, called Laser Powder Bed Fusion (L-PBF), for the job. This employs a laser beam to weld together particles on a thin bed of powdered metal, to form the required shape of the object’s first layer. Then more powder is added and a second layer is welded on top of the first. And so on, until the item is complete.

德穆思接到的任務(wù)之一是要想辦法用一種非常專門化的鋼材建造一個12米寬的包含諸多復(fù)雜特征的聚變室。他考慮使用一種被稱作激光粉末床熔合（Laser Powder Bed Fusion，L-PBF）的3D打印技術(shù)。它用激光束將薄薄一層金屬粉末中的顆粒燒結(jié)在一起，形成物體第一層所需的形狀。然后添加更多粉末，在第一層上面燒結(jié)第二層。以此類推，直至整個構(gòu)造完成。

The problem is that, as with most other forms of 3D printing, there is an inverse relationship between resolution, which governs the level of detail that can be printed, and the speed of the process. Hence, some large components with fine details can take days, if not months, to print. Producing the chamber looked as if it might take decades. L-PBF was clearly unfeasible for such an application.

問題是，與大多數(shù)其他類型的3D打印一樣，精度（可被打印的細節(jié)水平）和打印速度呈反比關(guān)系。因此，打印一些構(gòu)造精細的大型組件可能需要幾天甚至幾個月。建造這個聚變室看起來要花上幾十年。在這種情況下用L-PBF顯然不可行。

This got Mr DeMuth and a group of colleagues thinking about how to speed things up without compromising quality. After some work, they started using a device called an optically addressed light valve, which had been developed at LLNL. This permits a pulsed infrared laser, with its beam shaped to have a square cross-section, to be patterned with a high-resolution image. Working a bit like a photographic negative, the image can block or pass light, creating millions of tiny laser spots, much like the pixels that make up a digital image.

這促使德穆思和他的一幫同事思考如何在不影響質(zhì)量的情況下加快速度。一番研究之后，他們開始使用LLNL開發(fā)的一種設(shè)備，名叫光尋址光閥（optically addressed light valve）。這個設(shè)備讓脈沖紅外激光器發(fā)出的激光束（截面呈正方形）按照一幅高分辨率圖像來構(gòu)成圖案。圖像的作用有點像照相底片，可以阻擋激光或是讓激光通過，從而產(chǎn)生數(shù)百萬個微小的激光點，就像組成數(shù)字圖像的像素一樣。

When projected onto a bed of powder, this patterned laser light can weld a complete area in one go. Mr DeMuth likens the process to producing documents with a printing press instead of writing them out individually with a pen.

當(dāng)激光投射到一層粉末上時，按預(yù)定圖像透過的激光可以一次性燒結(jié)一個完整的區(qū)域。德穆思將這一過程比作用印刷機生成大量文件，而不是用筆一份份寫出來。

Not such a dotty idea

這點子可不瘋

In 2015 Mr DeMuth co-founded Seurat Technologies, to commercialise the technology. This Massachusetts-based firm is named after Georges Seurat, a post-impressionist French artist who pioneered a painting style called pointillism that builds pictures up from dots. Several companies, including GM and Volkswagen, a pair of carmakers, Siemens Energy, a division of a large German group, and Denso, a big Japanese components firm, have partnered with Seurat to explore the use of its first prototype area-printing machine.

2015年德穆思和其他人一同創(chuàng)立了修拉科技（Seurat Technologies），將這項技術(shù)商業(yè)化。這家總部位于馬薩諸塞州的公司以喬治·修拉（Georges Seurat）的名字命名。修拉是一位后印象派法國藝術(shù)家，他開創(chuàng)了一種叫做點彩的繪畫風(fēng)格，用點組成圖畫。有幾家公司已經(jīng)與修拉科技合作，共同探索使用其首款區(qū)域打印機的原型機，其中包括汽車制造商通用和大眾，德國大型集團西門子的子公司西門子能源以及日本大型零部件公司電裝（Denso）。

This prototype produces a series of small, patternable squares on the powder bed. Their size depends on the material. Aluminium requires 15mm squares. Titanium requires 13mm. Steel requires 10mm. Individually, these squares might seem small. But 40 of them can be printed adjacent to each other every second, so a large area can be covered quickly. The prototype was designed to work at this scale to keep the size of the laser and the amount of energy it consumes to a practical level.

這個原型機在粉末層上生成一系列可以制作圖案的小正方形。方形的大小取決于材料。鋁需要15毫米的方形。鈦需要13毫米。鋼需要10毫米。這些正方形單個來看可能很小，但是每秒鐘可以打印40個相互鄰接的正方形，所以能快速覆蓋大面積區(qū)域。該原型機以這種規(guī)模工作，就可以將所用激光器的大小和所消耗的能量保持在合理可行的水平上。

With the equivalent of 2.4m pixels projected in each square, the machine can print parts with layers just 25 microns (millionths of a metre) thick at a rate of 3kg an hour. This is ten times faster than a typical L-PBF machine at such a fine resolution, says Mr DeMuth. Production versions of the area printer are now being built, and future generations of the machine should end up being 100 times faster.

這臺機器在每個正方形上投射了240萬個激光點，以每小時3千克的速度、每層僅25微米（百萬分之一米）的厚度打印零件。德穆思說，在如此高的精度下，它比一般的L-PBF機器快10倍。這款區(qū)域打印機的量產(chǎn)機正在制作中，未來幾代的機器應(yīng)該會快100倍。

All that, says Mr DeMuth, means area printing will be competitive with mass-production factory processes, such as machining, stamping and casting. As an example, he believes that by 2030 it will be possible to produce silverware (utensils that nowadays are made from stainless steel) for $25 a kilo. “That means we could actually print silverware cheaper than you could stamp them out,” he adds.

德穆思表示，這一切意味著區(qū)域印刷將能與大規(guī)模生產(chǎn)的工廠工藝競爭，如機械加工、沖壓和鑄造。比方說，他相信到2030年有可能以25美元一公斤的價格生產(chǎn)不銹鋼餐具。 “這意味著我們打印餐具的成本其實比沖壓生產(chǎn)要低?！彼a充道。

Other laser-based 3D printers are getting faster, too. L-PBF machines, for example, may be fitted with several beams—though the complexity involved could limit their number. And many non-laser ways to print things are improving as well, using all manner of materials to make items ranging from buildings to bridges to biscuits. One way or another, then, 3D printing seems at last to be ready to give traditional factories a run for their money.?

其他基于激光的3D打印機也越來越快。例如，L-PBF機器也許可以安裝多個激光束——不過數(shù)量不能太多，不然結(jié)構(gòu)就太復(fù)雜了。許多非激光的打印方法也在改進，用各種材料來制作從建筑、橋梁到餅干的各種東西。無論如何，3D打印似乎終于準備好與傳統(tǒng)工廠競爭了。