化学蚀刻参数对激光粉末床熔化钛合金多孔结构表面残粉去除效果的影响

Effect of Chemical Etching Parameters on the Removal of Residual Powder from the Surface of Laser Powder Bed Fusion Titanium Alloy Porous Structures

目的采用超声辅助化学蚀刻的方法,去除激光粉末床熔化(Laser Beam Powder Bed Fusion,L-PBF)技术成形的多孔结构表面残粉,提升多孔结构的表面精度和质量。方法利用超声辅助化学蚀刻试验平台,探究溶液配比、蚀刻时间、蚀刻温度对粉末去除效果的影响。对比分析不同工艺参数处理后的试件表面形貌、支杆直径、质量变化。结果超声辅助可以显著提升化学蚀刻后的表面质量;蚀刻温度在30~60℃范围内,试件蚀刻后的尺寸精度最高;采用溶液体积比为HF∶HNO_(3)∶H_(2)O=4∶14∶82,加热温度为50℃,蚀刻9 min,试件的尺寸精度误差可低至0.24%。结论通过蚀刻时间与溶液浓度的合理配比,可以有效去除试件表面的残粉,提升试件的表面质量,残粉去除率达到了91.9%;通过增加酸性溶液浓度、控制溶液温度,可以将蚀刻效率提升2倍以上,同时达到有效去除残粉和提升蚀刻效率的效果。

Porous titanium alloy bone implants are extensively utilized in the biomedical field due to their superior properties.Laser Beam Powder Bed Fusion(L-PBF),an advanced 3D printing technology,constructs material layer by layer,reducing manufacturing waste and enabling highly customized bone implant designs.This technology significantly enhances the ability to produce complex geometrical structures.However,the samples formed by L-PBF often retain a considerable amount of adhered powder on their surfaces,which severely affects their dimensional accuracy and surface quality.Consequently,there is a need for effective post-processing methods to remove this adhered powder.Chemical etching is a proven technique for such surface removal.In this study,samples with a 5×5 lattice structure were prepared based on Body-Centered Cubic(BCC)units by L-PBF technology.Then,an ultrasonic-assisted chemical etching process was employed to remove the powder adhered to the surface of the L-PBF-formed lattice structure.An ultrasonic-assisted chemical etching experimental platform was also utilized to systematically investigate the effects of solution composition,etching time,and etching temperature on powder removal efficacy.By conducting a comparative analysis of the surface morphology,rod diameter,and weight loss rate of samples treated under different process parameters,it was found that ultrasonic assistance significantly improved surface quality during chemical etching.The highest dimensional accuracy of the samples was achieved when the etching temperature was maintained within the range of 30-60℃.Under solution composition of HF∶HNO_(3)∶H_(2)O=4∶14∶82,after heating to 50℃,and etching for 9 min,a dimensional accuracy error as low as 0.24%was achieved.Further research demonstrated that by appropriately adjusting the etching time and solution concentration,the residual powder on the sample surface could be effectively removed,achieving a removal rate of up to 91.94%.Additionally,controlling the chemical etching temperature within an appropriate range not only effectively removed residual powder but also significantly enhanced etching efficiency by more than twofold.The study also found that after ultrasonic-assisted chemical etching,the surface morphology of the sample was markedly improved,resulting in smoother surfaces and significantly reducing residual powder.These findings indicated that ultrasonic-assisted chemical etching was an effective post-processing method that could significantly enhance the surface quality and dimensional accuracy of porous titanium alloy structures fabricated by L-PBF.This provided crucial technical support for the manufacturing of porous bone implants.This research not only lays the foundation for the biomedical application of porous titanium structures but also offers valuable insights for the further development and application of L-PBF technology.The ultrasonic-assisted chemical etching process has proven to be highly effective in removing residual powder and improving the surface characteristics of titanium alloy lattice structures created by L-PBF.The enhanced dimensional accuracy and surface smoothness achieved through this method are critical for ensuring the successful integration and functionality of bone implants in biomedical applications.By optimizing etching parameters such as solution composition,etching time,and temperature,this study makes a significant contribution to the field of additive manufacturing.It demonstrates how advanced post-processing techniques are in elevating the performance and quality of 3D-printed components.The findings underscore the potential of ultrasonic-assisted chemical etching as a key technology for the future of personalized medical implants,offering a pathway to more efficient,precise and effective production methods.This research paves the way for innovations in biomedical implants and advances the capabilities of L-PBF technology in creating complex,high-quality titanium alloy structures.