Would this be considered a breach of intellectual property?

If an iPhone repair company registered the domain "iChipped.com", while another iPhone repair company operating in the same geographic area already used the domain "iCracked.com"

Aren't the words chipped and cracked used interchangeably?

If you want legal advice, ask a lawyer.

Even if the words are used interchangeably in language, they are sufficiently different for the purpose of creating a trademark for a business or web site.