The relationship of cutting force with hole quality in drilling process of AISI H13 steel

Abstract

Abstract. The harmony of the drilling machine-cutting tool-work piece is very important for producing the machine part with the ideal dimensions. For this purpose in this study, the effect of cutting forces on hole quality (surface roughness, diameter deviation and circular deviation) was investigated by 14 mm diameter uncoated and (AlCrN monolayer) coated carbide drills for drilling AISI H13 hot work tool steel on vertical machining center. Four different cutting speeds (60, 75, 90 and 108 m / min) and three different feed rates (0.15, 0.20 and 0.25 mm / rev) were used in the experiments. Cutting forces have been found to be effective in improving hole quality. Better hole quality has obtained with coated drills than uncoated drills in experiments. It has been observed that coated drills have the effect of improving the hole quality due to the operation with less cutting force and better chip evacuation.

Investigation of the microstructure, machinability and hole quality of AISI 1045 steel forged at different temperatures

“…Therefore, less roughness value was obtained than the surface roughness obtained in sample A due to the evacuation of sawdust by scratching the hole walls in the drilling of the forged samples. [23][24][25] In addition, the surface roughness values obtained at 80 m/min cutting speed of sample A were expected to decrease with the cutting speed being 120 m/min, but they were close to each other (Figure 5). This situation occurs due to the fact that the increased temperature increases the chip plastering with the acceleration of sawdust evacuation as a result of the increased cutting speed.…”

“…Therefore, the deviation amplitude of the drill from the bore axis has decreased due to the decreasing advance force, and the values of circularity, cylindricity and taper have decreased. 24,25 However, although the advance force of the untreated sample A was less than the forged samples, the values of circularity, cylindricity and taper were higher. This situation is attributed to the excessive size of the hole.…”

“…Easier chip deformation and accelerated sawdust evacuation led to a decrease in feed force. [14][15][16][17][18][19][20][21][22][23][24] The chemical and physical properties of the material affect the feed force and workability. The forward force obtained in the processing of sample A (untreated) was less than that obtained with the forged samples.…”

“…This situation can be explained by the decrease in feed force as a result of increasing cutting speed. [23][24][25] Therefore, chip deformation, which increases with the increase in cutting speed and with less cutting force, caused the rapid evacuation of the chip and the movement of the drill along the hole axis with less feed force, resulting in a smaller deviation amplitude of the drill from the axis of the hole. Therefore, the decrease in the deviation amplitude of the drill from the hole axis caused a decrease in the circularity, cylindrical and conical values.…”

“…He stated that this situation increased the deflection amplitude of the drill from the hole axis with the increasing forward force. 24 Kivak et al emphasized that cutting parameters are an effective parameter in hole quality in the drilling process and increasing feed force worsens the hole quality. 25 In the studies, it is seen that the hardness of the material increases with the reduction of the grain structure and the removal of microvoids with the forging process, and the material hardness decreases with the increase of the forging temperature.…”