铝合金薄壁中空结构件重负荷铣削切削力研究

使用粉末冶金高速钢和硬质合金刀具,在机床转速n为3 000~8 000 r/min、进给速度vf为300~3 200mm/min、轴向切深ap为5~20 mm、径向切宽aw为5~20 mm的切削用量范围内对铝合金薄壁中空结构件重负荷铣削加工切削力及其影响因素进行研究.结果表明:在筋板交叉处切削力有剧烈波动,其值为切削单层铝合金时的8—10倍;在较宽的切削用量组合范围内,刀具工件系统易发生自激振动;刀具易发生刀尖崩刃和涂层剥落.机床转速是影响切削力的最显著因素,使用冷风气动喷雾射流冲击冷却方式、较大的刀具螺旋角、较多的刀具齿数和后波刃刀具可有效降低切削力.

Research of Cutting Forces of Heavy Milling of Aluminum Thin-Walled Hollow Structural Components

Sintered high speed steel and carbide tools are used to investigate the cutting forces and the contributing factors of heavy milling alutninum thin-walled hollow structural components. The cutting parameters are confined to spindle speed n = 3 000 -8 000 r/min, feed speed vf= 300 - 3 200 mm/min, depth of eut ap = 5 - 20 mm and width of cut aw = 5 - 20 mm. The results show that the cutting forces fluctuate tempestuously when the intersection of the thin wall is cut, whose maximum forces are 8 to 10 times bigger than those of cutting the monolayer aluminum; self-exited vibration is more likely to occur if the cutting parameters are wide in range; it is likely that the knifepoint chips and the coated carbide tool peels. Spindle speed is a factor that crucially affects cutting forces. The following method can be used to reduce the cutting forces： using cryogenic pneumatic mist jet impinging cooling, bigger helical angle, more tooth number and wave edge.