Do Jehovah's Witnesses allow remarriage after a divorce? Are there any consequences for the congregation member?

I have 3 questions to Jehovah's Witnesses about how they view marriage/divorce: 1. Do Jehovah's Witnesses allow a person to divorce and marry someone else? 2. If it is allowed only in some cases, what cases are those? 3. Will a congregation member get excommunicated if they divorce and marry someone else, or are there other consequences?