Patent ID: 7424822

Claim:
A micro-hardness measurement method for calculating the hardness by pushing an indenter in a test sample and forming an indentation, comprising: extracting load data showing the a relationship between load L applied to the indenter and a depth δ, to which the indenter is pushed in from a surface of the test sample, to a maximum load L 0 , which is a load at a maximum depth δ 0 ; extracting unloading data showing a relationship between the load L applied to the indenter after the load is unloaded and the depth δ; judging, by comparing the unloading data with the load data, whether or not a load fluctuation amount from the maximum depth δ 0 when unloading the load is within a first permissible range; judging, when it is judged that the load fluctuation amount is within the first permissible range, whether or not the load at the depth δ 1 (δ 1 <δ 0 ) when unloading the load or the load fluctuation amount in a vicinity of the depth δ 1 is within a second permissible range; calculating a virtual depth δ v based on an inclination of a tangent line at the maximum depth δ 0 of an unloading curve obtained from the unloading data (a) when it is judged, one of that the load fluctuation amount is not within the first permissible range, or regarding the maximum depth δ 0 as a virtual depth δ v , or of calculating a virtual depth δ v based on an inclination of a tangent line at the depth δ 1 of a load curve obtained from the load data, (b) when it is judged that the load or the load fluctuation amount is not within the second permissible range; and calculating the hardness based on the virtual depth δ v and the maximum load L 0 .