Diode area melting - a novel re-configurable multi-laser approach for efficient additive manufacturing with enhanced thermal process control

激光粉床熔化(LPBF)是一种添加剂制造(AM)技术，近年来在航空航天、汽车和医疗领域制造高价值终端部件的工业用途显著增加。它被广泛认为是传统制造工艺的一种颠覆性替代方案，能够以低材料损耗创造出几何效率高的复杂结构。然而，LPBF加工方法二十多年来没有发展，使用电流扫描系统和高功率光纤激光器(1070 nm波长)选择性地熔化粉床中的薄层原料。这种方法在LPBF系统的可扩展性、加工效率(由于激光吸收差、壁塞效率低)以及伴随快速熔池凝固的热过程控制方面带来了挑战。不好的热控制会进一步导致残余应力的发展和部件内部的热撕裂，这反过来又限制了可加工合金的范围。为了克服与最先进的LPBF相关的限制，我们将创造具有无与伦比的工艺热控制的下一代多激光LPBF工艺，从而在附加制造能力方面实现根本性的变革。我们将构建一种新的制造设备，集成高度可扩展、波长优化的多激光器方法，称为二极管区域熔化(DAM)。这种方法将结合一个带有x147可单独寻址的激光二极管的激光头，在吸收效率高的波长和低单独功率下工作。二极管激光器将堆叠在一个独特的2D阵列中，通过在生成的熔池之前和之后立即激活横向激光源来实现先进的原位热预热/后热。该仪器还将集成混合激光光源，使用可重新配置的激光加工和振镜扫描方法实现进一步的过程控制，并定制大面积二极管光学预热。通过先进的热控制，该仪器将能够减少残余应力的形成，并创造出新颖的特定部位定制微结构，这是新一代产品，其能力超过了传统的LPBF。

Laser powder bed fusion (LPBF) is an Additive Manufacturing (AM) technique that has in recent years seen a significant increase in industrial usage for the manufacture of high-value end-use components in the aerospace, automotive, and medical sectors. It is widely viewed as a disruptive alternative to conventional manufacturing processes, capable of creating geometrically efficient and complex structures with low material wastage. However, LPBF processing methodology has not evolved in over two decades, using galvo-scanning systems and high power fibre lasers (1070nm wavelength) to selectively melt thin layers of feedstock from a powder bed. This approach creates challenges in regards to LPBF system scalability, processing efficiency (due to poor laser absorption, wall-plug efficiency) and thermal process control accompanied by rapid melt-pool solidification. Poor thermal control can further lead to residual stress development and hot-tearing within components which in turn limits the range of processable alloys available. In order to overcome limitations associated with state-of-the-art LPBF, we will create the next generation in multi-laser LPBF processes with unrivalled process thermal control, creating a radical step change in additive manufacturing capability. We will build a new manufacturing instrument integrating a highly scalable, wavelength optimised, multi-laser approach known as Diode Area Melting (DAM). This approach will incorporate a laser head with x147 individually addressable laser diodes, operating at absorption efficient wavelengths and low individual power. The diode lasers will be stacked in a unique 2D array enabling advanced in-situ thermal pre/post-heat by activating traversing laser sources immediately before and after the generated melt pool. This instrument will also integrate hybrid laser sources enabling further process control using re-configurable laser processing with galvo-scanning approaches and bespoke large area diode optical pre-heating. Through advanced thermal control this instrument will enable a reduction in residual stress formation and create novel site-specific customised microstructures, a new generation of products with capabilities exceeding those of traditional LPBF.