Impression creep of lead

The impression creep behavior of lead was investigated using a 100 μm diameter punch at ambient and elevated temperatures (433 K-563 K) under punching stresses of 6–70 MPa. The results were compared with the data obtained from conventional creep tests reported in the literature. Unlike the indentation creep test, the impression creep test showed a steady-state velocity after a short transient period when the flat-end cylindrical punch was pushed against the lead surface by a constant load. Both the temperature and stress dependences were comparable to those of the constant stress tensile creep tests under similar conditions. A master curve for lead was established by collecting data from the impression creep tests and the constant stress tensile creep tests. The indentation creep measurements for lead were included also. However, the indentation data depend on the load applied.