7] pointed out the importance of the layer thickness and the fact that a decrease in the layer thickness leads to the reduction of the surface roughness. Surface roughness indicating the initial peaks as a function of time for: (a) deposition angle α = 90 and (b) deposition angle α = 0 [16]. The application of specific chemicals initiates the reactions on the surface of the plastic part.
As a result, the surface roughness (Ra) on the top surface of the part was significantly reduced, as shown in Figure 10. The use of specific chemicals initiates the reactions on the surface of the plastic part. As a result, the surface roughness (Ra) on the top surface of the part was significantly reduced, as shown in Figure 10.
It was found that higher cutting speed and rake angle increase the surface roughness of the parts. Machining with the heated cutter: (a) shape of the cutter and (b) direction of machining. Machining with the heated cutter: (a) shape of the cutter and (b) direction of machining.
It was found that high laser power (greater than 3 W) and small beam diameter (less than 175 µm) led to surface corrugations.
Finishing of the Metal Parts
They studied the influence of the feed rate, duration, frequency and energy of the pulse on the surface roughness. They found that the laser polishing can reduce the surface roughness (Sa) of the complex thin-walled part to 5.39 μm. The surface roughness of the additively manufactured Ti6Al4V block was successfully reduced from 90 µm to 4 µm in the work of Ma et al.
They found that the laser polishing can reduce the surface roughness (Sa) of the complex thin-walled part to 5.39µm. 58] performed LSP on the AM-ed Inconel 718 cylinder to increase the surface hardness. The fatigue performance of the SLM-ed AlSi10Mg parts was investigated in the study by Uzan et al.
Two minutes of finishing resulted in the removal of partially melted particles from the surface. The surface of the AM part had an arc-shaped texture due to the SLM process. 74] used electrochemical mechanical polishing (ECMP) to reduce the surface roughness of internal channels of AM-ed 316L steel.
The surface roughness of the part can be reduced to as low as 50 nm, according to the reviewed studies. The surface roughness of the front surface was higher than the surface roughness of the top surface. In their study, they reduce the surface roughness Ra from 18 to 3.5 μm using 8 μm amplitude vibrations.
In their study, they reduce the surface roughness Ra from 18 to 3.5 µm using 8 µm amplitude vibrations. It was found that both methods significantly reduce the surface roughness of the part and partially remove the melt powders from the surface. It was found that increasing the number of cycles in abrasive flow finish asymptotically reduced the surface roughness.
In addition, after AFF, residual compressive stresses were present in the surface layer of the workpiece. 117] combined MAF with a grinding process and reduced the surface roughness (Ra) of SLM-processed AlSi10Mg from 7 to 0.155 µm.
Research Trend and Limitations
119], the inner surface of the double-layer SLM-ed Inconel 718 tube was polished using magnetic abrasives. It can be observed that the values fluctuate and any post-processing technique can be applied to achieve the desired reduction in surface roughness. Coating Application Wax coating for FDM Can be used for investment casting Can lead to dimensional inaccuracies.
It leads to a small decrease in surface roughness and, at the same time, it cannot finish complex profiles. On the other hand, abrasive grinding, grinding and micromachining can produce a fine surface roughness at the nano level. UNSM is one of the related processes in which plastic deformation is applied to the surface using a low-amplitude high-frequency vibration tool to soften the surface.
On the other hand, abrasive grinding, grinding and micromachining can produce a fine surface roughness at the nano level. Among the energy-assisted mechanical processes that were considered, this is the most flexible and can be applied to finish internal cavities of any shape. Finally, laser polishing is one of the most widespread processes for finishing AM metal parts.
Additionally, it can be done on the same machine that the part was built with. An overview of the finishing operations that can be used with metal AM is shown in Table 2. Can be applied on a micro and macro scale Can be applied to various shapes, complex surfaces.
Slow tool wear without immediate changes in process accuracy Abrasives can be recycled more cost effectively compared to polishing, engraving. It doesn't waste material because it rewrites it Similar to laser-based AM technologies, and it can be. It can cause compressive stresses on the workpiece surface or transform existing tensile stresses into.
Conclusions
Several processes provide an ultra-smooth surface and near-nano-level finishing, but they lack the flexibility of chemical finishing. Abrasive flow machining appears to be the most successful of the considered processes in terms of final roughness and the ability to finish complex cavities. Laser polishing can change the microstructure of the subsurface of the parts, leading to increased hardness.
However, compared to chemical finishing, it cannot finish complex-shaped cavities due to the geometry of the electrode. However, the choice of the finishing operation or a combination of operations can also lead to a deterioration of the workpiece quality if the control parameters are not chosen carefully. Furthermore, the pre-treatment and optimization of the post-treatment process can be decisive for the resulting product.
Furthermore, for future work, finishing technologies should be further explored to adapt to the increasing demands of the AM industry. Effects of laser polishing on the surface quality and mechanical properties of PLA parts built by fused deposition modeling.J. Effect of laser polishing on the microstructure and mechanical properties of 316L stainless steel fabricated by laser powder bed fusion. Mater.
Influence of laser polishing on the surface roughness and microstructural properties of the remelted surface boundary layer of tool steel H11.Mater. Process-dependent porosity and the influence of shot peening on porosity morphology with respect to selective laser-melted AlSi10Mg parts.Addit. On the effect of shot peening on the fatigue resistance of AlSi10Mg samples prepared by additive manufacturing using selective laser melting (AM-SLM).Addit.
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Surface quality and material removal in magnetic abrasive finishing of selective laser melted 316L stainless steel.J. Investigation of magnetic abrasive finish of AlSi10Mg alloy produced by selective laser melting.Int.