Hello CheezyDonut,
It depends on what the vow is, how grave the infraction was, and the decision of his superiors.
Unless it is a very grave offense, they are generally not directly booted from the Order. A religious community is meant to support their members spiritually, emotionally, and physically. This extends to helping a member struggling with their vows overcome this defect within their religious vocation.
There are some which are almost always grounds for expulsion from the Order: a hidden sexual relationship or the sexual assault of a person, knowingly refusing an order which has been given by a superior under the vow of obedience, sequestering funds (whether licitly or illicitly obtained) in a hidden bank account for personal use. Even if the vow is a solemn one, the Order retains the right to expel the religious from the Order in extreme and emergency cases before a Papal indult releasing the religious from their vows is granted.
In our Order, we also take a solemn vow not to seek ecclesiastical dignities (positions of authority or honors) within or outside of our Order. In this case, if a member actively seeks to subvert the valid position of another member for the purposes of obtaining it himself or actively seeks the procurement of a diocesan position or honor for himself, then it is grounds for expulsion (and has happened before).
Generally, anything less than this is mediated within the Order and is attempted to be corrected. This is not to say that there will be no punishment. Often grave infractions which do not result in expulsion are accompanied from punishments like removal from a position of authority removal from public ministry. Almost always, this punishment is accompanied by another program of formation to make sure that it does not happen again.
Now, the weight of the vow must also be taken into account. If the vow is a Simple one, as many order use today, then it is specifically the purview of the Order to decide upon punishment. Solemn vows, like my Order takes at final profession, are a public matter of the Church. As such, if the breaking of the vow publicly affects the faithful, then the Bishop of the Diocese or his representative may become involved with the resulting punishments and may file a complaint against the religious and the Order with the Congregation for the Institutes of Consecrated Life if he is not satisfied that the punishment does not fully address the infraction of the Solemn Vow.
Hope this helps,
Br. Ben, CRM