當前3D列印金屬技術的研究蓬勃發展，尤其在金屬件的製造技術上，從最初的選區雷射燒結（SLS）逐步發展到選區雷射熔融（SLM），使技術愈加成熟。然而，儘管列印技術不斷進步，金屬積層製造因為製程參數複雜的原因，在製造過程中，製程參數必須朝向高度有效地控制材料之應力與變形，避免最終產品產生缺陷，無法製造出列印金屬件之高品質及良率。例如，列印產品之孔隙率程為關鍵變異指標。針對孔隙率，現今主流的金屬表面檢測方法多採用X射線或CT掃描，雖然這些技術能提供高精度之品質檢測，但設備成本高昂造成產線之普及率不高，在實務生產環境無法大量應用。
本論文針對穿隧磁阻（TMR）傳感器應用於SLM產品之孔隙率檢測，設計在不同製程參數下列印出的鐵磁金屬樣品，並進行表面磁場檢測，分析訊號與製程參數之關聯性。基於TMR感測器的高靈敏度性質，本論文提出之量測方法可建構低成本且高效率之品質控制檢測方法，並於線上檢測及優化生產過程，達到提升3D列印金屬件之高良率及高品質之生產目標。

The research on current 3D printing metal technologies has been rapidly advancing, especially in the field of metal part manufacturing. The technology has evolved from the initial Selective Laser Sintering (SLS) to Selective Laser Melting (SLM), making the process more mature. However, despite continuous advancements in printing technology, metal additive manufacturing still faces challenges due to process-related issues. During manufacturing, process parameters must be carefully controlled to better manage stress and strain, which makes it more susceptible to product defects. As a result, the manufactured metal parts often struggle to achieve consistent quality, with variations in critical indicators such as porosity. Current mainstream metal surface inspection methods mostly use X-ray or CT scanning. Although these techniques provide high-precision inspections, they are costly and not widely accessible, limiting their application in real-world production environments.
This study explores the use of Tunnel Magnetoresistance (TMR) sensors for surface magnetic field inspection of ferromagnetic metals printed with SLM under different process parameters, analyzing the correlation between the surface magnetic field and the process parameters. This approach holds the potential to provide a low-cost and efficient inspection method for quality control, helping users further optimize the production process and improve the consistency of 3D printed metal part quality.