High temperature Gleeble microtensile testing of metallic micro specimens

Abstract

Engineering of micro parts is an increasingly important area of industrial activity and this field is rapidly developing further. Thus, the simulation of micro parts also becomes more and more important. As reliable material data is required to obtain accurate simulation results, test setups are also necessary to determine the material properties. An experimental setup for microtensile testing of stainless steel micro specimen (i. e., specimen with at least one dimension below 1 mm) to obtain material data in the temperature range from 20 to 350 °C is presented herein. Heating of the specimen is based on Joule (resistive) heating as it is done in macroscopic testing in Gleeble machines. Contactless measurement of temperatures is conducted by an infrared (IR) camera and the determination of strain by a combination of optical microscopy and digital image correlation (DIC). First samples were made from the stainless steel 17-4PH and the results obtained are presented and discussed in comparison with macroscopic properties of this material.

Adiabatic self-heating determination for Ti6Al4V at different temperatures

“…This approach, although it could be more accurate, notably hampers the data treatment. Thermocouples, however, influence the heat flow acting as thermodynamic fins, they have limited tran- sient response and they only allow single point measurements to be made [12,13] . In addition, the spatial resolution of thermocouples is limited, making them an unsuitable option when high thermal gradients are expected [14] .…”