Comparison of mechanical and geometrical properties of octet lattice structures using the electron beam melting

Öz

Additive manufacturing methods allow to produce complex geometries such as lattice structures. Aim of this study is to identify octet truss lattice structure’s mechanical capabilities. Firstly, octet truss structure designed and used to fill specimens. Specimens 1, 2 and 4 with wall and lattice structure, specimen 3 only with lattice structure and also a filled specimen are modelled. Modelled tensile specimens are additively manufactured from Ti-6Al-4V with Electron Beam Melting method. A comparison between specimens having same structural design (1, 2 and 4) has been made to gain insight about consistency of EBM method. Tensile experiments have been made with all of the specimens and tensile strength difference that can be considered significant determined among specimen 1, 2&4. Specimen 3 resulted not to be a practical approach as it showed poor tensile strength values. Lastly, tensile stress results of filled specimen are shared and compared with the other types of specimens. These results are providing a good sight for assessment of both octet truss structure and EBM manufacturing technology.

Anahtar Kelimeler

• Lattice structures
• Octet truss
• Ti-6Al-4V
• Additive manufacturing

Elektron ışın eritme yöntemi kullanılarak sekizli kafes örgü yapıların mekanik ve geometrik özelliklerinin karşılaştırılması

Öz

Katmanlı üretim yöntemleri, kafes yapıları gibi karmaşık geometrilerin üretimine izin veren yeni bir teknolojidir. Bu çalışmanın amacı sekizli kafes yapısının mekanik özelliklerini belirlemektir. İlk olarak, kafes yapısı oluşturulmamış ve tamamen dolu bir numune kullanılmıştır. 1,2 ve 4 numaralı numuneler duvar kalınlıkla kafes yapıdan modellenmiş, yalnızca 3 numaralı numune duvar kalınlıklı sekizli kafes yapısından oluşturulmuştur. Modellenen çekme numuneleri, Elektron Işını Eritme yöntemi ile Ti-6Al-4V'den malzeme kullanılarak üretilmiştir. EBM yönteminin tutarlılığı hakkında fikir edinmek için aynı yapısal tasarıma (1, 2 ve 4) sahip numuneler arasında bir karşılaştırma yapılmıştır. 1, 2 ve 4 numaralı numuneler arasında önemli sayılabilecek gerilme mukavemeti farkı belirlenmiştir. Numune 3, zayıf gerilme mukavemeti değerleri göstermiştir. Son olarak, doldurulmuş bir numunenin çekme gerilmesi sonuçları paylaşılmış ve diğer numunelerin sonuçlarıyla karşılaştırılmıştır. Bu sonuçlar hem sekizli kafes yapısı hem de EBM üretim teknolojisinin değerlendirilmesi açısından önemlidir.

Anahtar Kelimeler

• Kafes yapıları
• Sekizli örgü kafes yapılar
• Ti-6Al-4V
• Eklemeli imalat

Kaynakça

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