Problem

Cause

Solution

Deposit peels off

1. Poor preparation of the surface (oxidized or dirty surface)

2. Required surface roughness is >Ra 5.

3. Too low preheating temperature

4. Too high preheating temperature

Clean the surface well.

Sand blast well.

Preferable >Ra10

Increase preheat

Decrease preheat

Cracks

1. Overheating

2. Too fast cooling

3. Hardened base material

Slower cooling / controlled cooling

Porosity

1. Poor preparation of the surface.

2. Incorrect spray parameters

3. Incorrect spray distance

4. Poor sealings in the gun

5. Incorrect particle distribution for the gun

6. Too high oxygen level in the powder /oxidized powder.

7. Powder contains hollow particles

Clean the surface well.

Sand blast well.

Adjust parameters

Adjust distance

Replace seals