Lazerle metal toz ergitme prosesinde kalıntı gerilmelerin mikro girinti tekniği ile incelenmesi

Toz yatağında lazerle eklemeli (katmanlı) imalat ile metal malzemeden fonksiyonel parça üretimi yaygınlaşmakta ve geniş malzeme spektrumu sayesinde çok sayıda endüstri tarafından tercih edilmektedir. Bununla beraber konvansiyonel imalat yöntemlerine göre daha az olgunlaşmış olan Lazerle Metal Toz Ergitme (LAM) prosesi açısından aşılması gereken bazı kısıtlamalar söz konusudur. Yüksek ergime-katılaşma hızına sahip prosesteki temel problemlerden biri kalıntı (artık) gerilmelerdir. Farklı sayıdaki kalıntı gerilme ölçüm yöntemleri arasında, mikro girinti tekniği yeni yatırım ihtiyacı olmaması açısından avantajlıdır. Bu makalede LAM prosesi ile üretilmiş, bir nikel süperalaşımı olan ve havacılıkta yaygın olarak kullanılan Inconel 625 malzemedeki kalıntı gerilmeleri mikro girinti tekniği ile tespit edilmiştir. Elde edilen değerlerin, literatürde aynı teknik ile incelenmiş diğer nikel süperalaşımlarla uyumlu olduğu görülmüştür.

Anahtar Kelimeler:

Toz yatağında lazerle eklemeli (katmanlı) imalat, Inconel 625, Kalıntı gerilmeler, Mikro girinti

INVESTIGATION OF RESIDUAL STRESSES BY MICRO INDENTATION IN SELECTIVE LASER MELTING

Selective Laser Melting (SLM) of functional parts production from metals are becoming widespread and are preferred by many industries thanks to their wide material portfolio. However, there are still challenges that need to be overcome for the emerging SLM process which is relatively immature in comparison to conventional manufacturing methods. One of the main challenges for the process is the high melting-solidification rate resulting in residual stresses. Among the different number of residual stress measurement techniques, micro indentation has the advantage of not requiring new investments. In this article, residual stresses of SLMed Inconel 625, which is a nickel superalloy widely used in aerospace, were investigated by the micro indentation technique. The values obtained were found to be compatible with other nickel superalloy studies available in the literature.

Keywords:

Laser powder bed fusion, Inconel 625, Residual stresses, Micro indentation,

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