Investigating the Relationship between CrB Phase through Image Processing and Mechanical Properties of Metal 3D Printed Alloy

The relationship between the quantified CrB phase via image processing method and the mechanical properties of 3D printed SUS316L with boron was examined. Nine experimental conditions, i.e., boron content, feed rate, laser power, and scan speed, were designed by Taguchi method. The formation of CrB phase in 3D printed alloy with nine process conditions was quantified using image processing method. The image processing algorithm was based on the intensity difference between the regions of CrB phase and others. The CrB phase directly affects the mechanical properties of the 3D printed stainless steel. The quantity of CrB phase and mechanical properties depend on the processing conditions. The mechanical properties for tensile strength and micro hardness with processing conditions were measured. The same processing conditions were used for both quantification of the CrB phase and the mechanical properties test. The relationship between the quantified CrB phase and the mechanical properties was identified. As is generally known, a high amount of CrB phase deteriorates the mechanical properties of materials. Therefore, optimization of the processing conditions is crucially required to achieve the desired mechanical properties. With the signal the signal-to-noise (S/N) ratio analysis, the S/N ratio results for the quantified CrB phase were compared with that for the measured mechanical properties. The comparison through S/N ratio analysis contributes to determination of the influence of the CrB phase on the mechanical properties. Also, the comparison helps in finding of the desired mechanical properties.