Evaluating Method Of The Fracture Toughness Using Instrumented indentation testing

The present invention in that the method fracture toughness measurement by the continuous indentation test method for flat flat measuring the load and the indentation depth while applying a load of the press as a specimen of the punch shape in real time about how fracture toughness measurement by the continuous indentation test method according, indentation test performed step, conversion step of converting the set load displacement curve to the generalized curves of stress and a press-in depth compared indenter radius to perform the indentation test by setting the indentation depth as the press having the set radius to generate a set load displacement curve initiating cracks at the time of crack initiation in the generalized curve stress, finding a crack initiation time, obtain a press-in depth compared indenter radius at the crack initiation point, crack initiation stress, crack initiation indentation depth compared indenter radius at the time, the press is set's radius value or set by calculating the values ​​of the indentation depth to be press-fitted the press-party And a step, adjusting the adjusted load displacement curve generation step of generating a load displacement curve according to the indenter having a radius adjusted to calculate the adjusted radius.