| 摘要: | 粉末冶金多孔模具的設計，對壓型機送粉的品質的要求甚高，因為品質會攸關到最終成品的機械性質及尺寸大小，隨著模穴數量的增加，會發現愈靠外側的模穴所生產出來的成品品質，會愈加不穩。由於送粉裝置送料鞋(Powder Feeding Shoes, PFS)大多使用金屬材質，製作上會受限於傳統機械加工能力，無法做出客製化且外觀輪廓複雜的外型。隨著工業技術的進步，引入3D列印技術之熔融沉積成型技術(Fused Deposition Modelling, FDM)製作PFS，但因表面粗糙度的不佳，導致送粉裝置的情況未達改善，且使用不同粉末生產時，會產生混粉的風險。故本文藉光固化技術(Stereolithography, SLA)製作出表面粗糙度優良之PFS，得以提升PFS送粉品質的效果。
綜合上述原因，本研究將依粉末冶金生產流程比較FDM與SLA各項數據差異，內容分三個部分:實驗在第一部分為確認SLA在3D列印PFS時的最佳參數，本實驗重點為尺寸大小與表面粗糙度。由於列印角度會影響積層製造技術成品的表面粗糙度，因此針對送料鞋管件部位進行實驗，設計三種不同管件部位與列印平台的夾角參數(5°、45°、85°)，最終得出的結果為5°是最佳列印參數。第二部分將FDM與SLA送料鞋分別安裝至機台，在使用同樣參數下生產，比較壓胚的壓高壓重，再依製程能力指標(Process Capability Indices, PCIs)分析。實驗結果顯示，SLA所生產的壓胚，具有較優良的送粉品質，而FDM的送料鞋所生產的壓胚在壓高數據顯示是不良的，尺寸都接近下限。第三部分，燒結後收縮率計算結果， FDM的收縮率相較SLA來說，離理論值0.8%少了0.017%。代表在一開始送粉製作壓胚時的填粉的密度就已經不足了，這會使得模具在開發設計上，無法達到設計者當初預期的收縮比，這會使得燒結後成品的尺寸與機械性質受到影響。根據以上分析結果，最終得出SLA製作的送料鞋可以提升送粉品質，從FDM的PFS收縮比數據為0.783%與利用SLA製作的PFS數據0.795%，提升了0.012%，降低送粉不均問題。
;The design of porous molds in powder metallurgy demands high-quality powder distribution in pressing machines, directly impacting the mechanical properties and dimensions of the final product. Powder Feeding Shoes (PFS), primarily composed of metal materials, face limitations in traditional machining methods, hindering the production of customized and intricately contoured designs. With the advancement of industrial technology, the incorporation of Fused Deposition Modelling (FDM) in PFS production has been explored. However, challenges persist due to inadequate surface roughness, impeding improvements in powder feeding device performance and posing risks of powder mixing when different materials are used. This paper employs Stereolithography (SLA), a light-curing technology, to enhance the surface roughness of PFS, aiming to improve the quality of powder feeding.
Considering the aforementioned challenges, this study conducts a comparative analysis of FDM and SLA technologies within the powder metallurgy production process. The research is structured into three main sections. In the first section, the focus is on confirming optimal parameters for SLA 3D printing, emphasizing size and surface roughness. Given that print angles impact the surface roughness of layered manufactured products, experiments were conducted on specific parts of the powder feeding shoe. Three different angles (5°, 45°, 85°) between the feeding shoe components and the printing platform were designed, with the results indicating that a 5° angle yielded the optimal printing parameters. In the second section, FDM and SLA powder feeding shoes were installed on the machine and produced under identical parameters. The study compares pressing height and weight of the green compacts, followed by an analysis using Process Capability Indices (PCIs). Results reveal that SLA-produced green compacts exhibit superior powder feeding quality, whereas FDM-produced green compacts exhibit poor pressing height data, nearing the lower limit. In the third section, post-sintering, the shrinkage rate of FDM is found to be 0.017% lower than that of SLA, deviating from the theoretical value of 0.8%. This suggests insufficient initial powder filling density during FDM green compact production, impacting mold design and resulting in an inability to achieve the anticipated shrinkage ratio. In conclusion, SLA-produced Powder Feeding Shoes show promise in enhancing powder feeding quality, addressing challenges associated with uneven powder feeding. This research contributes valuable insights to the optimization of 3D printing technologies in the production of intricate components in powder metallurgy. |
