SIGMA PHASE FORMATION IN A HEAT TREATED NI-۵۰CR COATING APPLIED BY HVOF PROCESS ON A STAINLESS STEEL
عنوان مقاله: SIGMA PHASE FORMATION IN A HEAT TREATED NI-۵۰CR COATING APPLIED BY HVOF PROCESS ON A STAINLESS STEEL
شناسه ملی مقاله: JR_IJMSEI-5-4_005
منتشر شده در در سال 1387
شناسه ملی مقاله: JR_IJMSEI-5-4_005
منتشر شده در در سال 1387
مشخصات نویسندگان مقاله:
J. Saaedi
H. Arabi
Sh. Mirdamadi
Th. W. Coyle
خلاصه مقاله:
J. Saaedi
H. Arabi
Sh. Mirdamadi
Th. W. Coyle
Abstract: Two different coating microstructures of Ni-۵۰Cr alloy were obtained on a stainless steel substrate by
changing combustion characteristics of a high velocity oxy-fuel (HVOF) process and the size distribution of feed
powder during coating process. Use of the finer feed powder and leaner fuel in oxygen/fuel ratio (i.e. using a ratio
much less than stoichiometric ratio) led to formation of an extremely dense coating with high oxide content. Heat
treating of this coating at ۶۵۰ºC for ۴ hours caused the formation of an intermetallic sigma phase having Cr۷Ni۳
stoichiometry. Formation of this phase has been reported occasionally in thin films not in thermal spray coatings, as
reported for the first time in this research. In addition no sigma phase was detected in the HVOF as-deposited coating
with low oxide content after heat treatment of the samples. Therefore, due to the limited number of papers available in
the subject of formation of phase in either Ni-Cr bulk alloys or coatings, it is considered appropriate to show up a
case in this field. In this work, the formation of sigma phase in Ni-۵۰Cr coating deposited by HVOF technique and
heat treated at ۶۵۰ºC was discussed and then the coating was characterized.
کلمات کلیدی: sigma phase; HVOF; oxide phases; thermal sprayed coatings; Ni-۵۰Cr.
صفحه اختصاصی مقاله و دریافت فایل کامل: https://civilica.com/doc/1723361/