That's not realistic, conflict will always exist and kids will always get angry. It's knowing what to do with that anger that's critical. Knowing how to resolve conflicts could save a child's life. Know when to intervene. Some conflicts take care of themselves.
Kids often find a way of working things out without getting into a full-blown fight.
Sometimes our involvement can add fuel to the fire. Use preventative maintenance. If you see increased irritability or elevating emotions, step in before the conflict has a chance to completely erupt. Separate your kids and have them cool off - take slow deep breaths, get a drink of water, wash the face, engage in physical activity. Doing any of these will help diffuse angry emotions.