- 标题
- 摘要
- 关键词
- 实验方案
- 产品
-
Laser Based Machining of Aluminum Metal Matrix Composites
摘要： Aluminium metal matrix composites (Al MMC) are a relatively new type of material which combine lightweight metallic matrices (aluminium) with hard ceramic reinforcements (like alumina fibre or silicon carbide particles). Al MMCs have excellent potential in various applications from automotive to aerospace; however, their use is currently limited due to their low machinability. Conventional laser processes such as the laser drilling or cutting of monolithic materials (metals/alloys) are well-established processes. However, conventional laser processing of anisotropic materials like metal matrix composites is challenging due to the immense differences in the chemical and physical properties of the matrix and reinforcement. Over the last decade, nanosecond laser based water jet guided (WJG) machining has securely established itself as a novel laser based machining process, especially for the machining of non-monolithic materials like composites. The main investigation of this paper is centred on understanding the performance of WJG laser and conventional high power fibre laser machining of Al MMC. Laser machining of both fibre-based and particle-based Al MMC has been investigated (Al2O3 Fibre–Al MMC; SiC Particle–Al MMC). The WJG laser machining results were compared with the results from conventional long pulse/continuous wave laser process.
关键词： Water-jet guided laser machining,Metal matrix composite,Laser beam machining
更新于2025-09-16 10:30:52
-
Ablation Investigation of Cemented Carbides Using Short-Pulse Laser Beams
摘要： As an excellent engineering tool material, cemented carbides are capable to shape and cut metallic materials with high surface finish quality and precision. However, in regard to conventional abrasive methods cemented carbides are difficult-to-machine materials due to their extreme hardness combined with relatively low toughness. In contrast, laser beam machining is an advanced non-contacting cutting method which is therefore suitable for shaping hard materials. In particular, the application of short-pulse laser beams enables the cutting of hard materials meeting high precision requirements. Moreover, it can effectively reduce defects induced by mechanical contacts and thermal reactions. In this paper, a general study of the ablation mechanism of cemented carbides using short-pulse laser is conducted. Special attention is paid to the correlation between the material ablation and machining parameters within the nanosecond regime: pulse number and pulse energy. In doing so, two cemented carbide grades with similar composition but different grain size have been chosen as investigated materials. An experimental set-up equipped with a nanosecond laser and an auto-stage is implemented to produce dimples on the cemented carbide surfaces with variable pulse number and pulse energy. The experimental design and characterization of geometrical features of produced dimples are presented and discussed. The work is complemented with a thorough surface integrity assessment of the shaped materials. It is found that ablation increases proportionally with the pulse number and applied energy. Regarding microstructural effects, ablation is discerned to be more pronounced in the coarse-grained grade as compared to the medium-sized one.
关键词： laser beam machining,short-pulse laser,surface integrity,cemented carbides
更新于2025-09-12 10:27:22