Friction and wear behaviour and abradability of abradable seal coating

International audienceThe friction and wear behaviour of several kinds of middle temperature abradable seal coatings used in aircraft turbine engine was investigated. Their abradability was evaluated by sliding worn volume. The mechanisms of the sliding wear of the coatings are abrasive wear, adhesive wear and oxidation wear, but the weight of the adhesive wear and abrasive wear is different in different coatings and under different test loads. The results show that the abradability decreases with the increase of the hardness for a given kind of coating. Even if the hardness is close, the abradability is very different in different kinds of coatings. So, only by the hardness can the level of abradability not be not judged and the coating not be chosen and designed. The abradability of M313 type of coating is the best, M310 is close to M601 and M307 with low hardness is fairly good, but M307 with high hardness is the worst