According to the Hadith, Israfil (Raphael in Arabic) is the Angel responsible for signalling the coming of Judgment Day by blowing a horn and sending out a "Blast of Truth". Unlike Jibrail(Gabriel) and Mikail(Michael), this archangel was not mentioned by name in the Quran.
Israfil is the angel given the ‘soor’ (literally means Horn, Trumpet). He is ready to blow the blasts ushering in the Day of Judgement upon Allah's command.
It is reported the Messenger of Allah sallah Allah alayhi wa sallam said, "How can I enjoy myself when the one with the ‘Soor’ has raised the ‘Soor’ to his mouth, knitted his brow and is waiting to blow? They said, "What should we say, Messenger of Allah? He replied, "Say: Allah is enough for us, and the best Guardian. We have put our trust in Allah. (At-Tirmidhi).
The ‘du’a’ (supplication) of the Prophet sallah Allah alayhi wa sallam concerning these three angels is, "O Allah, Lord of Jibril, Mika’il, and Israfil, Bringer of the heavens and the earth into being, Knower of the unseen and visible, it is You who judges between Your slaves concerning the things about which they disagree. Guide us to the truth in respect of the things about which there is disagreement by Your permission. You guide whomever You will to a straight path."
Wa Allahu A'lam.