As a natural and environmentally friendly renewable material, Northeast China ash wood (NCAW) (Fraxinus mandshurica Rupr.) was cut by water-jet assisted CO2 laser (WACL), the surface quality was evaluated by surface roughness of cut section. The surface roughness was measured by three-dimensional (3D) profilometry. Furthermore, the micromorphology of machined surface was observed by scanning electronic microscopy (SEM). Carbon content changes of machined surface were measured by energy dispersive spectrometer (EDS). A relationship between surface roughness and cutting parameters was established using response surface methodology (RSM). It is concluded that the cutting speed, laser power and water pressure played an important role in surface roughness of cut section. The surface roughness increased as an increase in laser power. It decreased caused by increasing of cutting speed and water pressure. Measurements revealed that the surface quality of NCAW part was improved using the optimized combination of cutting parameters. The established quadratic mathematical model of a good prediction is helpful for matching suitable cutting parameters to obtain expected surface quality.

Waterjet-Guided Laser (WJGL) machining is an advanced technique providing efficiency and precision for wood machining. The present study investigates the practical demonstration and analysis of laminated object manufacturing (LOM) WJGL for thin wood machining. A theoretical process of wood laser cutting was established, expressing relations between the cut kerf width and the influencing parameters. WJG Nd: YAG laser system was utilized for machining Korean pine and Northeast China ash specimen of 3 mm thickness, each with 7.21 and 7.13% of water content, respectively, under different machining conditions. The effects of process parameters and influences on woodcut surface geometry were analyzed via analysis of variance (ANOVA) and scanning electron microscopy (SEM). The investigated parameters include the laser cutting speed, power, kerf width, heat-affected zone (HAZ), and cut surface roughness. The study shows that the kerf width and surface were significantly influenced by WJGL power, followed by the cutting speed. For both wood specimens, at a fixed laser cutting speed of 2.36 mm/s, the kerf width increases significantly with laser power, affecting the cut surface quality accordingly. At 6 W and 8 W, the cut kerf geometry and surface quality were excellent for the Pinus Koraiensis, with kerf widths of 0.79 and 0.852 mm, respectively. At a fixed laser power of 8 W, the kerf width decreases with the cutting speed, affecting the cut surface quality. At a cutting speed of 4.33 mm/s, an excellent cut surface of Fraxinus mandshurica was observed with 0.808 mm of kerf width. Depending on the machining conditions, the kerf width variations of Korean pine were more significant than the Northeast China ash. LOM-WJGL is an efficient and eco-friendly technique for thin wood processing. Graphical Article Highlights: Practical modeling demonstration of waterjet guided laser (WJGL) wood machining. Experimental investigation of different wood specimens under influenced process parameters and machining conditions. Characterization and identification of suitable wood types for efficient and eco-friendly applications.

High-quality wood products and valuable wood crafts receive everyone’s favor with the rapid development of the economy. In order to improve the cutting surface quality of wood forming parts, the cutting experiment of renewable Fraxinus mandshurica was conducted by waterjet-assisted CO2 laser (WACL) technology. A quadratic mathematical model for describing the relationship between surface roughness changes and cutting parameters was established. The effects of cutting speed, flow pressure and laser power on the kerf surface roughness of Fraxinus mandshurica when cutting transversally were discussed by response surface method. The experimental results showed that kerf surface roughness decreased under a lower laser power, higher cutting speed and higher flow pressure. When the cutting speed was 30 mm/s, flow pressure was 1.58 MPa and laser power was 45 W, the actual surface roughness of the optimized Fraxinus mandshurica was 2.41 μm, and it was in accord with the theoretically predicted surface roughness value of 2.54 μm, so the model fitted the actual situation well. Through the analysis of 3D profile morphology and micromorphology, it was concluded that the optimized kerf surface of Fraxinus mandshurica was smoother, the cell wall was not destroyed and the tracheid was clear. It provides the theoretical basis for wood micromachining.