Hello,everyone! The purpose of this thread is to share the experience
of the thermal spray parameters . As a beginner , I don't know how to solve the coating problems with changing the thermal spray parameters .For example , what should I do if there are lots of unmelted particles in the coating .... etc.May be someone can tell me the link of troubleshooting on the website ?

Hi Powerplant

to the Surface Engineering Forum.

I will kick off by saying the best way to learn and gain experience on this topic, is by getting intimate with your spraying equipment and the process. Observe and listen to the effects of changing certain parameters. After a while you may be capable of taking an unknown powder and quickly setting the equipment to produce a reasonable coating just by sight and sound, at least to a point you can consider as starting point parameters for further more scientific optimisation. With a bit of free plasma time and a pot of powder you don't mind wasting, have a serious play, changing various parameters and noting their effects (note of caution, keep within operational range of equipment and hardware. Viewing a range of established parameters for your particular hardware should give you an idea on the parameter extremes). Believe me, you can't get this experience and feeling for the process sitting behind a desk and studying the books only, you need to get your hands dirty. To some extent you can see when the spray materials are too cold or hot or whether the powder is being injected to the right point in the plasma just by observation. It does surprise me sometimes when people say they have a problem, but have not taken a little time to observe their process in action close up. Surprising what you will learn viewing the plasma and powder injection close up (don't forget PPE and welding mask :rolleyes.

Reading and understanding the theory and relating this to your practical observations is also very important in understanding process optimisation and troubleshooting. You will find various threads on this forum and the old message board discussing such topics. Try doing some searches, like in your example for "unmelts" or "unmelted" or "unreacted particles" etc. "Nature of thermal spray coatings" may help with basic understanding of coatings.

A short generic troubleshooting guide I think probably would not be worth much as most problems tend to be rather unique, depending on equipment, powder and desired coating characteristics etc. If it was that simple, I think I would be out of a job

Hope you enjoy learning about the process. I will leave some space for others to comment.

Hi , Gordon;

Thanks a lot for your useful reply.As you told me , I am trying to "get my hands dirty", and I think with the time , I can learn a lot and got lots of experiences on thermal spray ...