Frnt brake pads and rotors replaced twice. After day grinding noise on slow stop

return for warranty work something is very wrong. poss caliper is sticking or worse

What grade of pads and rotors are being used? sometimes pad material that does not 'match' rotor type will make noise due to certain friction characteristics , and would be normal. Have you tried OEM Volvo parts?

I agree with ziptie's comments...use Volvo parts and this will not be an issue...with the right aftermarket parts it should be OK, but it doesn't sound like these are the right ones...go for OEM