Effect of Surface Treatment on the Formation of Oxygen Enriched Brittle Layer in A Ti3A1-Nb Alloy

1994 ◽  
Vol 364 ◽  
Author(s):  
B. Zhang ◽  
X. Wan ◽  
D. Li ◽  
J. Wang ◽  
H. Wang ◽  
...  
Keyword(s):  
Titanium Nitride ◽  
Partial Pressure ◽  
Surface Treatment ◽  
Thermal Exposure ◽  
Nitride Layer ◽  
Oxygen Atmosphere ◽  
Pressure Oxygen ◽  
Brittle Layer ◽  
Vapor Deposit ◽  
Effect Of Surface

AbstractEffect of surface treatment on the formation of oxygen enriched brittle layer in a Ti3Al-Nb alloy was investigated. The results show that a mixed Ti2N and TiN layer was formed at the surface by the titanium nitride vapor deposit treatment, and this titanium nitride layer makes it possible to suppress the formation of the oxygen enriched brittle layer during thermal exposure. An Al2O3 film was formed at the surface of the alloy, when the surface treatment was conducted under a low partial pressure oxygen atmosphere. However, such surface treatment is not able to depress the formation of the oxygen enriched brittle layer during thermal exposure, due to the higher affinity of α2 phase for oxygen as well as the higher diffusivity of titanium in Al2O3.

Development of Surface Treatment Techniques to Improve Oxidation Resistance of Titanium Aluminide

1990 ◽  
Vol 213 ◽  
Author(s):  
Michiko Yoshihara ◽  
Ryohei Tanaka ◽  
Tetuya Suzuki ◽  
Masayuki Shimizu
Keyword(s):  
Heat Treatment ◽  
Partial Pressure ◽  
Surface Treatment ◽  
Oxidation Resistance ◽  
Titanium Aluminide ◽  
Combined Treatment ◽  
Diffusion Coating ◽  
Oxygen Atmosphere ◽  
Preferential Formation ◽  
Pressure Oxygen

ABSTRACTThe oxidation resistance of intermetallic compound TiAl was greatly improved in cyclic heating at 900°C by means of a new type of surface treatment, which is the heat treatment under a low partial pressure oxygen atmosphere. The treatment becomes more effective with increasing aluminum content in the specimen. It was presumed that the excellent oxidation resistance resulting from this method is due to preferential formation of a thin and tighit Al2 O3 surface layer, which is formed during the surface treatment at a temperature vicinity of 1000°C and air pressure of about 10−3 Pa. The oxidation resistance of Al2O3 film formed, however, was found to be insufficient at 950°C. A combined treatment consisting of the heat treatment under a low partial pressure oxygen atmosphere followed by a diffusion coating with aluminum showed an excellent resistance to cyclic oxidation even at 950°C.

scholarly journals Effect of surface treatments on push-out bond strength of calcium silicate-based cements to fiber posts

2021 ◽  
Vol 21 (1) ◽  
Author(s):  
Amr M. Elnaghy ◽  
Ayman Mandorah ◽  
Ali H. Hassan ◽  
Alaa Elshazli ◽  
Shaymaa Elsaka
Keyword(s):  
Bond Strength ◽  
Surface Treatment ◽  
Glass Fiber ◽  
Calcium Silicate ◽  
Surface Treatments ◽  
The Other ◽  
Fiber Posts ◽  
Glass Fiber Posts ◽  
Push Out ◽  
Effect Of Surface

Abstract Background To evaluate the effect of surface treatments on the push-out bond strength of Biodentine (BD) and white mineral trioxide aggregate (WMTA) to fiber posts. Methods Two brands of fiber posts were used: Reblida post; RP and RelyX post; RX. Each type of post (n = 80/group) was divided into four groups (n = 20/group) and exposed to surface treatment as follows: Control (no treatment), sandblasting (SB), hydrofluoric acid (HF), and TiF4 4 wt/v%. Each group was further subdivided into two subgroups (n = 10/subgroup) based on the type of CSCs used as follows: Subgroup A: BD and Subgroup B: WMTA. Push-out bond strength of BD and WMTA to glass fiber posts was assessed. Data were statistically analyzed using three-way ANOVA and Tukey’s test. A Weibull analysis was performed on the push-out bond strength data. Results BD showed higher bond strength than WMTA (P < 0.001). The push-out bond strength for posts treated with TiF4 4 wt/v% showed greater bond strength than the other surface treatments (P < 0.05). The BD/RP-TiF4 4 wt/v% showed the greater characteristic bond strength (σ0) (15.93) compared with the other groups. Surface treatments modified the surface topography of glass fiber posts. Conclusions The BD/RP-TiF4 4 wt/v% showed greater bond strength compared with the other groups. The TiF4 4 wt/v% surface treatment enhanced the bond strength of BD and WMTA to glass fiber posts than the other treatments. Surface treatment of fiber post with TiF4 4 wt/v% could be used to improve the bond strength with calcium silicate-based cements.

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