With both high melting point and high thermal conductivity,boron carbide and copper (B4C/Cu) functionally gradient material (FGM) is considered to be a kind of ideal materials for plasma facing material (PFM) in fusion device.However,the preparation of B4C/Cu composite is difficult because of the quite difference of melting point between B4C and Cu.Spheroidization of powders is a good way to study the melting behavior when B4C and Cu powders are treated by radio frequency (RF) driven inductively coupled plasma,which has the advantage of high temperature and accelerated cooling.In this work,the influence of gas flow rates and the addition of H2 to Ar plasma gas on the melting,evaporation and oxidation behaviors of powder was investigated.