Niyobyum Altlık Metali Üzerinde Oksidasyona Dayanıklı Bir Yüzey Kaplamasının Geliştirilmesi

Nb (niobium) and Nb-based alloys are promising refractory materials for use at high temperatures. However, due to the weak resistance to high temperature oxidation, a dramatic modification in oxidation resistance is required to use Nb-based refractory materials. Alloying Nb with other elements improves its mechanical properties and oxidation resistance to some extent. An improvement in oxidation resistance by forming Al (aluminum) based coating with dense Al2O3 by utilizing different methods seems a prospective way for developing Nb-based refractory materials.   In the current study, halide activated pack cementation (HAPC) and subsequent plasma electrolytic oxidation (PEO) were combined to form an oxidation-resistant coating on niobium base metal. Prospective Al2O3 phases in amorphous or various kind of crystalline forms at the top were formed by anodic oxidation of cementation layer and modified to oxidation resistant a-Al2O3 by subsequent annealing at 1000oC for 2 hours in argon gas.   Comparing weight changes after oxidation tests shows that formed protective oxide film has a noticeable positive effect on the protection of Nb metal at high temperatures

A STUDY ON THE SURFACE ROUGHNESS OF GALVANNEALED LOW CARBON Al-KILLED AND Ti-Nb STABILIZED INTERSTITIAL FREE STEELS

In this study, the surface roughness of galvannealed low carbon Al-killed and Ti-Nb stabilized interstitial free steels was investigated using the industrial galvannealing process parameters. The iron content of the coatings was also analysed to establish a relationship with the surface roughness and coating composition. The surface roughness displayed an exponential behaviour with increasing of annealing time at each annealing temperature in both steel coatings, which was in an increasing order in the galvannealed low carbon Al-killed steel coating, whereas it was a reverse order in the galvannealed Ti-Nb stabilized interstitial free steel coating. The craters were observed on the galvannealed coatings resulting in high surface roughness. Increasing the iron content of the coatings leads to a reduction in the surface roughness with delta(1k) phase.WOS:0006973797000092-s2.0-8510891109

A study on the Surface Roughness of Galvannealed Low Carbon Al-Killed and Ti-Nb Stabilized Interstitial Free Steels

In this study, the surface roughness of galvannealed low carbon Al-killed and Ti-Nb stabilized interstitial free steels was investigated using the industrial galvannealing process parameters. The iron content of the coatings was also analysed to establish a relationship with the surface roughness and coating composition. The surface roughness displayed an exponential behaviour with increasing of annealing time at each annealing temperature in both steel coatings, which was in an increasing order in the galvannealed low carbon Al-killed steel coating, whereas it was a reverse order in the galvannealed Ti-Nb stabilized interstitial free steel coating. The craters were observed on the galvannealed coatings resulting in high surface roughness. Increasing the iron content of the coatings leads to a reduction in the surface roughness with δ1k phase