Water pump is this normal

[papou]

is it normal for the water impeller to keep it`s shape after removed from pump this is my second one this year i have different temp reading at different rpm`s on idle the temp would go past 180 my thermostat is a 160
my first impeller lasted 30 hours all fins were there it looked a little worse would not pump water no more the one in the pic has 40 hours and it would no longer pump on idle.

strainer,trans cooler ,hoses are all clear and clean.

Thanks