哪種技術將主導 3D 列印？

隨著 3D 列印（也稱為積層製造）日益成為先進製造的關鍵組成部分，進一步推動 3D 列印變得十分重要。

3D printing, also known as additive manufacturing, is rapidly becoming a crucial component of advanced manufacturing processes. As 3D-printed parts and components are frequently utilized in highly demanding applications, such as automotive engines, rockets, and military equipment, any failure in a single component can have catastrophic consequences.

3D 列印，也稱為積層製造，正在迅速成為先進製造流程的重要組成部分。由於 3D 列印零件經常用於要求很高的應用，例如汽車引擎、火箭和軍事設備，因此單一組件的任何故障都可能造成災難性後果。

To mitigate this risk and pave the way for 3D printing to become the dominant manufacturing method, surpassing traditional techniques like melting metal in casts and machining, continuous optimization of the 3D printing process is paramount.

為了降低這種風險並為 3D 列印成為主導製造方法鋪平道路，超越鑄造和機械加工中熔化金屬等傳統技術，持續優化 3D 列印流程至關重要。

Among the various 3D printing techniques, laser powder bed fusion is particularly suited for precision manufacturing. Researchers at the University of Wisconsin-Madison and Argonne National Laboratory have recently employed advanced X-ray imaging to analyze this process meticulously, uncovering promising avenues to drastically reduce defects during manufacturing. Their findings were published in the International Journal of Machine Tools and Manufacture, under the title “Revealing mechanisms of processing defect mitigation in laser powder bed fusion via shaped beams using high-speed X-ray imaging”.

在各種 3D 列印技術中，雷射粉末床熔融特別適合精密製造。威斯康辛大學麥迪遜分校和阿貢國家實驗室的研究人員最近採用先進的 X 射線成像來仔細分析這一過程，發現了大幅減少製造過程中缺陷的有希望的途徑。他們的研究結果發表在《國際工具機與製造雜誌》上，標題為「使用高速 X 射線成像的成形光束揭示雷射粉末床熔合中加工缺陷緩解的機制」。

The Mechanics of Laser Powder Bed Fusion

雷射粉末床熔融的力學原理

In powder bed 3D printing, a layer of powder containing the material used for additive manufacturing is spread out in a container. A laser then selectively melts/fuses the powder in the zone that will eventually form the 3D-printed item.

在粉末床 3D 列印中，含有用於積層製造的材料的粉末層鋪展在容器中。然後，雷射選擇性地熔化/熔合區域中的粉末，最終形成 3D 列印物品。

Following this, another layer of powder is deposited on top, and the portions that need to be melted and added to the item are once again targeted by the laser. By repeating this process over time, even highly complex shapes and relatively large items can be produced.

隨後，另一層粉末沉積在頂部，需要熔化並添加到物品中的部分再次被雷射瞄準。透過隨著時間的推移重複這個過程，甚至可以生產高度複雜的形狀和相對較大的物品。

You can observe laser powder bed fusion in action in this video, along with examples of items that can be made using this technique.

您可以在此影片中觀察雷射粉末床融合的實際情況，以及可以使用此技術製造的物品的範例。

This method is not limited to plastics; it can also be used to create items made of metals, including titanium, steel, cobalt-chromium, aluminum, and more.

這種方法不僅限於塑膠；它也可用於製造金屬製品，包括鈦、鋼、鈷鉻合金、鋁等。

The advantages of this method lie in its ability to create precise geometry, with tolerances of +/- 0.2mm, which are comparable to metal injection molding, and its efficiency in material usage, as the unused powder can be collected back and reused.

此方法的優點在於能夠創建精確的幾何形狀，公差為 +/- 0.2 毫米，可與金屬注射成型相媲美，其材料使用效率高，因為未使用的粉末可以回收並重複使用。

Moreover, by simultaneously using multiple lasers, which is typically found in more advanced 3D printer designs, larger parts can be printed quickly.

此外，透過同時使用多台雷射（通常在更先進的 3D 列印機設計中使用），可以快速列印更大的零件。

It's important to note that laser powder bed fusion encompasses several sub-techniques, including:

值得注意的是，雷射粉末床融合包含多種子技術，包括：

Revealing Mechanisms to Prevent 3D Printing Failures

揭示防止 3D 列印失敗的機制

In theory, additive manufacturing of metal parts should yield results equivalent to those obtained from traditional casted parts. However, in practice, issues can arise, such as pores, or “voids,” on the surfaces, and large spatters.

理論上，金屬零件的積層製造應該會產生與傳統鑄造零件相同的結果。然而，在實踐中，可能會出現一些問題，例如表面上的孔隙或“空隙”以及大的飛濺。

Such structural imperfections can lead to the parts breaking, which is unacceptable in critical applications.

這種結構缺陷可能導致零件斷裂，這在關鍵應用中是不可接受的。

“Because we understood the underlying mechanisms, we could more quickly identify the right processing conditions to produce high-quality parts using the ring-shaped beam.”

“因為我們了解基本機制，所以我們可以更快地確定正確的加工條件，以使用環形梁生產高品質的零件。”

Lianyi Chen – Associate professor of mechanical engineering at UW-Madison

Lianyi Chen – 威斯康辛大學麥迪遜分校機械工程副教授

The Ring-Shaped Laser Beam

環形雷射光束

The first modification made by the researchers to their 3D printing setup was to replace the standard laser beam with a ring-shaped laser beam, which was provided by nLight, a laser company specializing in semiconductor lasers.

研究人員對其 3D 列印裝置所做的第一個修改是將標準雷射光束替換為環形雷射光束由專門從事半導體雷射的雷射公司 nLight 提供。

This distinct shape facilitates better circulation of the melted metal within the melt pool overall and results in smaller waves on the surface of the freshly created item, reducing the size and distance traveled by the spatters.

這種獨特的形狀有利於熔化的金屬在熔池內更好地循環，並在新創建的物品表面產生較小的波浪，從而減少飛濺的尺寸和傳播距離。

Matching Model And Observations

匹配模型和觀察結果

The researchers went on to verify these observations using the high-energy synchrotron X-ray facility at Argonne National Laboratory. They employed this facility to capture high-speed snapshots of the 3D printing process, which allowed them to check whether their mathematical model accurately simulated reality.

研究人員繼續使用阿貢國家實驗室的高能同步加速器 X 射線設備驗證了這些觀察結果。他們利用該設施捕獲 3D 列印過程的高速快照，這使他們能夠檢查他們的數學模型是否準確地模擬了現實。

3D Printing At A Quicker Pace

更快的 3D 列印

Another achievement was the ability of the ring-shaped beam to penetrate deeper into the powder without causing more instability. This led to thicker layers without compromising the strength of the finished product.

另一項成就是環形光束能夠更深入地穿透粉末，而不會造成更多的不穩定。這導致了更厚的層而不影響成品的強度。

As the production ultimately requires fewer layers, this speeds up manufacturing and increases the overall productivity of the machine.

由於生產最終需要更少的層數，這加快了製造速度並提高了機器的整體生產率。

An Example of Powder Bed Fusion in Practice

粉末床融合的實作範例

This line of work is far from being merely an academic demonstration; it has the potential to directly improve powder bed fusion machinery already used in the industry.

這項工作遠非僅僅是學術演示；它有可能直接改進行業中已使用的粉末床熔融機械。

A prime example would be in aeronautics, with the fuel nozzle on General Electric’s GE9X engine, which is used on Boeing 777 aircraft.

一個典型的例子是航空業，通用電氣 GE9X 引擎上的燃油噴嘴，用於波音 777 飛機。

The GE9X is the largest turbo-fan engine produced, and the additively manufactured nozzle is five times more durable than previous versions.

GE9X 是生產的最大的渦輪風扇發動機，增材製造的噴嘴比以前的版本耐用五倍。

It's worth noting that such developments are still very recent, with the GE9X design being approved by the FAA in 2020.

值得注意的是，此類發展仍然是最近才出現的，GE9X 的設計已於 2020 年獲得美國聯邦航空局 (FAA) 的批准。

Even a higher quality powder bed fusion process, as well as a quicker one, could improve the design further while at the same time reducing its costs.

即使是更高品質和更快的粉末床熔融工藝，也可以進一步改進設計，同時降低成本。

The Future of 3D Printing: Advanced Manufacturing Domination

3D列印的未來：先進製造佔據主導地位

We have previously covered how 3D Printing is consolidating into the future of manufacturing.

我們之前介紹過 3D 列印如何融入未來的製造業。

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