In LRFD strength reduction factors depend on the material and the applied load (shear, axial moment) too? Or just material? Are they also called resistance factor?
In general speaking, the strength reduction factor reflect the confidence on a structural element's ability to withstand a certain type of loading. It is derived statistically from both the research experiments and the past experiences; and it is based on the structural response/behavior of a certain type of material subjected to a certain type of load. In this sense, you are correct in calling it a "resistance factor", which is always less than 1.