Özgür POYRAZ, Ezgi Uğur SOLAKOĞLU, Soner ÖREN, Cansinem TÜZEMEN, Güray AKBULUT

Toz yatağı katmanlı imalat prosesinde yüzey dokusu ve form karakterizasyonu

Toz yatağında lazer katmanlı (eklemeli) imalat sonrası elde edilen yüzey kalitesi, parçaların, boyutsal doğruluğu ve herhangi bir yüzey işlemi olmaksızın kullanımını sınırlandıran etkenlerden biridir. Bu durumun temel sebebi prosesin doğası gereği ortaya çıkan ve diğer katmanlı imalat proseslerinde de görülen merdiven etkisidir. Merdiven etkisi görülen bir komponent yüzeyindeki geometrik ve form hataları montaj edilebilirlik, akış performans düşüşü ve yorulma başta olmak üzere çok sayıda riski beraberinde getirmektedir. Merdiven etkisinin engellenmesi için katmanlı imalat proses parametreleri optimizasyonu, ikincil işlemler ile yüzey temizleme ve/veya proses modelleme uygulanabilir. Bunlar arasından ikincil işlemler, ek zaman ve maliyet ortaya çıkardığı için daha az tercih edilmektedir. Proses modellemede ise, literatürde kullanılan geometrik modellerin sadece katman kalınlığını dikkate alması, farklı malzeme ve proses parametreleri için yakınsama oranlarını yetersiz kılmaktadır. Bunlara ek olarak parametre optimizasyonu tek bir parçaya yönelik olduğunda, farklı geometrik unsurların etkileri görülememektedir. Bu çalışmada sırası ile düz, açılı ve farklı yuvarlatma yarıçaplarına sahip yenilikçi numune geometrileri tasarlanmış ve Inconel 625 malzemeden toz yatağında lazer katmanlı imalat ile üretilmiştir. Üretilen numuneler üzerinde yüzey dokusu ve form karakterizasyon incelemeleri gerçekleştirilmiştir. Farklı unsur ve ölçüler için elde edilen sonuçlar sunularak, geometrik özelliklere bağlı yüzey kalitesi ve form değişim eğilimleri elde edilmiş, parametrelerin etkileri tartışılmıştır.

Anahtar Kelimeler:

Toz yatağı katmanlı imalat, eklemeli imalat, yüzey dokusu karakterizasyonu

The surface quality obtained after laser powder bed additive manufacturing is one of the factors that limits the use of part without any surface treatment. The main reason of this situation is the stair effect form as a result of the layered nature of the process. Geometric and form errors on a component surface with a stair effect bring numerous risks, especially in terms of assembly operations, flow performance and fatigue resistance decrease. To prevent the stair effect and surface irregularities, parameter optimization, post processes and/or process modeling can be studied. Among these, post processes are less preferred because they result in additional time and cost. In the process modeling, the geometric models used in the literature only take into account the thickness of the layer, making the convergence rates for different material and process parameters inadequate. In addition, when the parameter optimization is directed for a single part, the effects of different geometrical elements cannot be seen. In this study, innovative test artifacts with flat, angled and curved faces were designed and produced with laser powder bed additive manufacturing of Inconel 625 material. Surface texture and form characterization studies were performed on the artifacts. By presenting the results obtained for different features and dimensions, surface texture and form change trends due to geometric properties were obtained and the effects of the parameters were discussed

Keywords:

Powder bed fusion, additive manufacturing, surface texture characterization,

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