LAZER TOZ YATAK FÜZYONU İLE ÜRETİLEN TI-6AL-4V ALAŞIMININ YÜZEY TOPOGRAFYASININ KARAKTERİZASYONU

Abstract

Lazer toz yatağı füzyonu (L-PBF), yüksek enerjili bir lazerin üç boyutlu bileşenler üretmek için metalik toz katmanlarını seçici olarak ergittiği bir eklemeli üretim süreci sınıfıdır. L-PBF karmaşık geometrilerin üretiminde önemli ilerlemeler sağlarken, üretilen parçaların düşük yüzey kalitesi hala sürecin bir dezavantajıdır. Üretilen parçalardaki yüksek yüzey pürüzlülüğü temel olarak eritme, katılaştırma ve soğutma süreçleri sırasındaki karmaşık termal geçmişten kaynaklanmaktadır. Bu çalışmada, Ti-6Al-4V tozundan L-PBF prosesi ile dikdörtgen numuneler üretilmiştir. Numunelerin hem üst hem de yan yüzeylerinin yüzey topografisi, yüzey pürüzlülüğü test cihazı ve taramalı elektron mikroskobu (SEM) kullanılarak karakterize edilmiştir. Yüzey pürüzlülüğünün kaynaklarının iki yönelim arasında önemli ölçüde farklılık gösterdiği bulunmuştur. Yan yüzeylerde, pürüzlülük ağırlıklı olarak kısmen erimiş toz partiküllerinin yapışmasından kaynaklanmaktadır. Aksine, üst yüzey pürüzlülüğü çeşitli kusurlardan etkilenir ve yumrulama fenomeni oldukça pürüzlü yüzeyler oluşturmada önemli bir rol oynar.

Keywords

• Eklemeli İmalat
• Lazer Toz Yatak Füzyon
• Ti-6Al-4V
• Yüzey Pürüzlülüğü

CHARACTERIZATION OF THE SURFACE TOPOGRAPHY OF THE TI-6AL-4V ALLOY FABRICATED BY LASER POWDER BED FUSION

Abstract

Laser powder bed fusion (L-PBF) is a class of additive manufacturing processes in which a high-energy laser selectively melts layers of metallic powder to fabricate three-dimensional components. While L-PBF enables significant advancements in the manufacturing of complex geometries, poor surface quality of the as-built parts is still a drawback of the process. High surface roughness in as-built parts is primarily caused by the complex thermal history during the melting, solidification, and cooling processes. In this study, rectangular samples were fabricated from Ti-6Al-4V powder by the L-PBF process. Surface topography of the samples in as-build state, both top and side surfaces, was characterized using a surface roughness tester and a scanning electron microscope (SEM). The origins of surface roughness were found to differ significantly between the two orientations. On the side surfaces, roughness is predominantly due to the attachment of partially melted powder particles. In contrast, the top surface roughness is influenced by several defects, with balling phenomena playing a major role in generating highly rough surfaces.

Keywords

• Additive Manufacturing
• Laser Powder Bed Fusion
• Ti-6Al-4V
• Surface Roughness

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