MCrAlY bend test

[liaemars]

Hi guys,
I have a quality control problem.
I have sprayed MCrAlY (Amdry 365-1) for a customer and he made bend test to check adhesion strength, but the coating cracks and spalls off and he won't accept it.
I know that MCrAlYs coating are brittle before heat treatment and I was wondering if there is any standard or documents to show that this test is not the right one for adhesion before heat treatment thị trường bất động sản.
Any help and info is appreciated.
Regards,
Lia

[loriolo]

Hi Lia
Long time ago it take a lot of time to have a correct set of parameters, because to spray a MCrAlY materials is very difficult, there is a lot of unmelted particles, low bond strength, the best result were obtained using nitrogen as primary gas (it depend of your specification), it is very important to check the perfect geometry of the gun, and a perfect alignment of the powder stream in the flame, this have to be done with accuracy, check sand blasting profile, coating temperature during spray, and after hundreds of parameters set, you can obtain good result