Eİ ile Üretilen SİP Uygulanmış Ti6Al4V Numunelerde Gözeneklilik Ölçümü – Arşimet Yöntemi ve MikroBT arasında Pratik bir Karşılaştırma

Öz

Bu çalışma Arşimet Yöntemi ve Mikro-BT (Bilgisayarlı Tomografi) ile boşluk/gözenek ölçümünün karşılaştırmalı bir incelemesini sunmaktadır. Eklemeli imalat (Eİ) ile üretilen Ti6Al4V numuneler 3 farklı Sıcak İzostatik Presleme (SİP) parametresiyle ardıl işleme tabi tutulmuş olup, bir grup da işlemsiz olarak bırakılmıştır. Toplam numune sayısı 16’dır ve her grup 4 numune ile temsil edilmiştir. Daha iyi mekanik özelliklere ulaşılabilmesi için süreç optimizasyonu ile mümkün olan en yüksek bağıl yoğunluğa (%100) ulaşılması ve kusurların morfolojisinin optimizasyonu hedeflenmektedir. SİP, numunelerin yoğunluğunu artırma bir diğer deyişle içindeki boşluğu en aza indirme ya da tamamen ortadan kaldırma konusunda öne çıkan ardıl işlem seçeneklerinden biridir. Tipik olarak işlemsiz numunelerdeki yoğunluk %99’un üzerinde çıkmaktadır. Özellikle yorulma dayanımı açısından malzemenin içindeki boşluklar, bu boşlukların yapısı ve dağılımı da çok önemlidir. Bu çalışmada, ilk grup olarak 920°C-100MPa-2 saat SİP, ikinci grup olarak 815°C-190 MPa-2 saat SİP, üçüncü grup olarak 920°C-100MPa-2 saat SİP ve ardından hızlı soğutma uygulanmış olup, dördüncü grup da işlemsiz olarak bırakılmıştır. Her numunenin yoğunluğu Arşimet Yöntemi’yle ölçülmüş ve her gruptan da 1 adet numuneye Mikro-BT yapılmıştır. Sonuçlar karşılaştırılmış ve bu iki yöntem arasında göreceli bir korelasyon bulunmuştur. Arşimet Yöntemi boşluk seviyesini ölçmek için hızlı ve ekonomik bir yöntemdir. Mikro-BT ise numune içindeki boşlukların konumlarını ve formlarını da tespit edebilme özelliğiyle Arşimet Yöntemi’nden ayrışmaktadır.

Anahtar Kelimeler

• Eklemeli İmalat
• Sıcak İzostatik Presleme
• Boşluk
• Arşimet Yöntemi
• Mikro-BT

Porosity Measurement for HIPped AM Ti6Al4V Samples – A Practical Comparison between Archimedes Method and Micro-CT

Öz

This study presents a comparative analysis of porosity measurement techniques using the Archimedes method and micro-computed tomography (Micro-CT) for additively manufactured (AM) Ti-6Al-4V components. The samples were subjected to four different post-processing conditions: three groups were processed using Hot Isostatic Pressing (HIP) with varying parameters, while one group remained in the as-built condition. A total of 16 samples were analyzed, with each group comprising four specimens. To enhance the mechanical performance of AM parts, particularly their fatigue strength, maximizing relative density (approaching 100%) and optimizing the morphology of the defects are primary objectives. Among post-processing techniques, HIP is one of the most effective methods for reducing or eliminating internal porosity, thereby increasing the overall density of as-built materials, which typically exhibit densities exceeding 99% of the theoretical value. The presence, morphology, and distribution of porosity are especially critical in determining fatigue behavior. The experimental setup included: Group 1: HIP at 920 °C, 100 MPa, for 2 hours, Group 2: HIP at 815 °C, 190 MPa, for 2 hours, Group 3: HIP at 920 °C, 100 MPa, for 2 hours with uniform rapid quenching, and Group 4: As-built condition (no post-processing) Density measurements were performed on all samples using the Archimedes method. Additionally, one representative sample from each group was partially scanned using Micro-CT to evaluate internal porosity characteristics. A comparative analysis of the results from both techniques revealed a consistent correlation between them. While the Archimedes method offers a faster, more cost-effective approach for quantifying overall porosity levels, Micro-CT provides valuable insights into the spatial distribution, size, and morphology of pores within the material—information that cannot be captured through the Archimedes technique alone.

Anahtar Kelimeler

• Additive Manufacturing
• Hot Isostatic Pressing
• Porosity
• Archimedes Method
• Micro-CT

Kaynakça

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