Purpose

Additive manufacturing (AM) has the potential to revolutionise the fabrication of complex surgical instruments. However, AM parts typically have a higher surface roughness compared to machined or fine cast parts. High surface roughness has important implications for surgical instruments, particularly in terms of cleanliness and aesthetic considerations. In this study, bulk surface finishing methods are described to produce end-use selective laser melting parts.

Design/methodology/approach

The aim was to achieve a surface finish as close as possible to machined parts (Ra = 0.9 µm, Wa = 0.2 µm, Pv = 7.3 µm). A sample coupon was designed to systematically evaluate different finishing techniques. Processes included bulk finishing, blasting and centrifugal finishing methods on individual parts, as well as heat treatment before and after surface finishing.

Findings

Abrasive blasting or centrifugal finishing alone was not adequate to achieve an end-use surface finish. White oxide vapour blasting at high water pressure was the most effective of the abrasive blasting processes. For centrifugal finishing, a 4 h runtime resulted in an acceptable reduction in surface roughness (Ra = 2.9 µm, Wa = 2.0 µm, Pv = 34.6 µm: inclined surface [30°]) while not significantly increasing part radii. The combination of finishing methods resulting in the smoothest surfaces was white oxide blasting followed by 4 h of centrifugal finishing and a final glass bead blast (Ra = 0.6 µm, Wa = 0.9 µm, Pv = 6.9 µm: inclined surface [30°]). The order of these methods was important because white oxide blasting was significantly less effective when applied after the centrifugal finishing.

Originality/value

Collectively, these results describe the development of a practical bulk finishing method for stainless steel surgical instruments produced by AM.

中文翻译：

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增材制造的不锈钢手术器械的表面处理

目的

增材制造（AM）具有革新复杂外科器械制造的潜力。但是，AM零件通常比机加工或精铸零件具有更高的表面粗糙度。高表面粗糙度对手术器械具有重要意义，尤其是在清洁度和美观方面。在这项研究中，描述了批量表面精加工方法以生产最终使用的选择性激光熔化零件。

设计/方法/方法

目的是获得尽可能接近机加工零件的表面光洁度（Ra = 0.9 µm，Wa = 0.2 µm，Pv = 7.3 µm）。样本试样被设计为系统地评估不同的修整技术。工艺包括散装精加工，单个零件的喷砂和离心精加工方法以及表面精加工之前和之后的热处理。

发现

单独的喷砂或离心抛光不足以达到最终用途的表面光洁度。在高水压下进行白氧化物蒸气喷砂是喷砂过程中最有效的方法。对于离心精加工，运行4小时可导致表面粗糙度的可接受降低（Ra = 2.9 µm，Wa = 2.0 µm，Pv = 34.6 µm：倾斜表面[30°]），而不会显着增加零件半径。最终表面最光滑的精加工方法相结合，先进行白色氧化物喷砂，然后进行4小时的离心精加工，最后进行玻璃珠喷砂处理（Ra = 0.6 µm，Wa = 0.9 µm，Pv = 6.9 µm：倾斜表面[30°]） 。这些方法的顺序很重要，因为当在离心精加工后进行喷砂处理时，白氧化物喷砂的效率明显降低。

创意/价值

总而言之，这些结果描述了由AM生产的用于不锈钢手术器械的实用批量修整方法的开发。