Investigation of the Effect of Heat Treatments at Different Temperatures on the Crystal Structure of Titanium-Nickel Films

Abstract

Titanium-nickel films have an increasing interest and an increasing potential use in recent years thanks to their shape memory properties and super elasticity properties. Titanium-nickel films grown by magnetron sputtering method have amorphous internal structure. In order to give shape memory and super elastic properties, these films are heat treated and the internal structure is transformed into crystal phase. In this study, titanium-nickel films grown by magnetron sputtering method were subjected to heat treatment in an atmosphere controlled tube furnace at six different temperature values. Phase changes of the films were determined by XRD analysis, micro structures were observed by SEM images and phase transformation temperatures determined by DSC analysis. As a result of the study, it was determined that different heat treatment temperatures greatly changed the internal structure. According to the results, it was determined that the heat treatment at 550 ° C was suitable for TiNi applications at room temperature.

Keywords

• titanium-nickel film
• shape-memory
• phase transformation
• heat treatment

Farklı Sıcaklıklarda Yapılan Isıl İşlemlerin Titanyum-Nikel Filmlerin Kristal Yapısına Etkisinin Araştırılması

Abstract

Titanyum-nikel filmler sahip oldukları şekil hafıza özelliği ve süper elastiklik özellikleri sayesinde son yıllarda giderek artan bir ilgiye ve artan bir potansiyel kullanım alanına sahiptir. Magnetron sıçratma yöntemiyle büyütülen titanyum-nikel filmler amorf iç yapıya sahiptir. Şekil hafıza ve süper elastik özelliklerinin kazandırılması için bu filmlere ısıl işlem yapılmakta ve iç yapı kristal faza dönüştürülmektedir. Bu çalışmada magnetron sıçratma yöntemi ile büyütülen titanyum-nikel filmler altı farklı sıcaklık değerinde atmosfer kontrollü tüp fırın içerisinde ısıl işleme tabi tutulmuştur. Filmlerin faz değişimleri XRD analizleri ile, iç yapıları SEM görüntüleri ile, faz dönüşüm sıcaklıkları DSC analizleri ile belirlemiştir. Çalışma sonucu farklı ısıl işlem sıcaklıklarının iç yapıyı büyük oranda değiştirdiği belirlenmiştir. Elde edilen sonuçlara göre 550°C de yapılan ısıl işlemin oda sıcaklığındaki uygulamalar için daha uygun olduğu tespit edilmiştir.

Keywords

• titanyum-nikel film
• şekil hafıza
• faz dönüşüm
• ısıl işlem

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