Oxidation behaviours of Nb–22Ti–15Si–2Al–2Hf–2V–(2, 14)Cr alloys with Al and Y modified silicide coatings prepared by pack cementation

Chromium Deposition on Cobalt-Based Alloys by Pack-Cementation and Behaviour of the Coated Alloys in High Temperature Oxidation

Two TaC-strengthened cobalt-based alloys, with compositions Co-10Cr-0.25C-4.4Ta and Co-10Cr-0.5C-8.7Ta (wt.%) underwent Cr-deposition by pack-cementation, followed by heat-treatment to allow Cr diffusing deeper in their sub-surface. Thereafter they were tested for 50 hours at 1200°C in a thermobalance. These alloys were successfully enriched in chromium, with a maximal content on surface of abo...

determination of olanzapine and thiourea using electrodes modified by dna and film of copper-cobalt hexacyanoferrate & investigation of electro-oxidation of some catechol derivatives in the presence of 4-phenylsemicarbazid

چکیده هدف از این کار بررسی الکترواکسیداسیون کتکول و مشتقات آن در حضور 4-فنیل سمی کاربامازید بوده است اکسیداسیون کتکولها ترکیبات نا پایدار کینونها را تولید می کنند که این ترکیبات می تواند در واکنش مایکل بعنوان پذیرنده نوکلئوفیل عمل نمایند. در ادامه اکسایش کتکولهای (a-c1) را درحضور 4-فنیل سمی کاربامازید در محلول آب/استونیتریل (90/10)بوسیله ولتامتری چرخه ای و کولن متری در پتانسیل ثابت مورد بررسی ...

Performance of Al-Rich Oxidation Resistant Coatings for Fe-Base Alloys

This multi-layer program has examined the oxidation resistance of Al-rich coatings made by chemical vapor deposition and pack cementation on ferritic-martensitic (e.g. T91, Fe-9Cr-1Mo) and austenitic (Type 304L, Fe-18Cr-8Ni) substrates at 650°-800°C. The main goal of this work was to demonstrate the potential benefits and problems with alumina-forming coatings. To evaluate their performance, ox...

Oxidation – Nitridation of Ni-Cr-Al Alloys

A series of alloys containing 24-36 wt pct Cr and 13.5 – 25.0 wt pct Al was reacted with air at 1100 °C for 260 h. The products of isothermal reaction were scales of α-Al 2 O 3 plus small amounts of Cr 2 O 3 . These grew according to parabolic kinetics, interrupted by episodic weight losses caused by partial spallation. No nitridation occurred during the isothermal exposures. Reaction during th...

Corrosion Protection of Al Alloys: Organic Coatings and Inhibitors