Al–Mg–Si系合金の切りくず折断性に及ぼすSi粒子の影響

抄録

Effect of Si particles on chipping characteristics of 6061 aluminum alloys during drilling operations has been studied. The formation of fine chips was promoted when more than 2 mass%Si was contained in the above alloys. The number of chips per unit weight, a parameter of chip breaking characteristics, was inversely proportional to the square root of the spacing of Si particles. The mechanism of fine chip formation is as follows through the microscopic observation on the cross section of the chips. The plastic strain is introduced around hard Si particles due to cutting force during the chip formation. The internal stress comes out in Si particles to go critical value. Finally, the cracked Si particles promote the crack propagation across the chips to form fine ones during drilling.