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With the rapid development of aviation and aerospace manufacturing technology, advanced composite materials
represented by carbon fibre reinforced plastics (CFRP) and super hybrid composites (fibre/metal plates) are more and
more widely applied. The fibres are mainly carbon fibre, boron fibre, Aramid fiber and Sic fibre. The matrixes are resin
matrix, metal matrix and ceramic matrix. Advanced composite materials have higher specific strength and higher specific
modulus than glass fibre reinforced resin composites of the 1st generation. They are widely used in aviation and
aerospace industry due to their high specific strength, high specific modulus, excellent ductility, anticorrosion,
heat-insulation, sound-insulation, shock absorption and high&low temperature resistance. They are used for radomes,
inlets, airfoils(fuel tank included), flap, aileron, vertical tail, horizontal tail, air brake, skin, baseboards and tails, etc. Its
hardness is up to 62~65HRC. The holes are greatly affected by the fibre laminates direction of carbon fibre reinforced
composite material due to its anisotropy when drilling in unidirectional laminates. There are burrs, splits at the exit
because of stress concentration. Besides there is delamination and the hole is prone to be smaller. Burrs are caused by
poor sharpness of cutting edge, delamination, tearing, splitting are caused by the great stress caused by high thrust force.
Poorer sharpness of cutting edge leads to lower cutting performance and higher drilling force at the same time. The
present research focuses on the interrelation between rotation speed, feed, drill's geometry, drill life, cutting mode, tools
material etc. and thrust force. At the same time, holes quantity and holes making difficulty of composites have also
increased. It requires high performance drills which won't bring out defects and have long tool life. It has become a trend
to develop super hard material tools and tools with special geometry for drilling composite materials.
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