A laser cutting process for the fracture splitting notch of a connecting rod was researched in this paper. According to the material behaviors

energy balance and the changes of hole shapes

the process was divided into three stages

initial state

quasi-steady destruction and tail stage. The affects of pulse width

waveform

pulse frequency and cutting speed on the notch root radius were analyzed

and a new pulse waveform was designed to satisfy the request of notch root sharpness. Analysis and experimental results show that a long pulse width combined with a reasonable cutting speed is the key to obtain a sharp fracture splitting notch. When the pulse width is set to be 1 ms

cutting speed to be 10 mm/s

the sharp fracture splitting notch can be obtained.Furthermore

for a deeper and sharper notch

it can be transformed into many long pulse processing by increasing the frequency. When the frequency is increased to 40 Hz

pulse width to 0.5 ms

the fracture splitting notch with a larger aspect ratio and a sharp root can be obtained. By comparison of the morphologies for the fracture splitting notch

it indicates that proposed process can achieve the sharp fracture splitting notch with higher quality by injecting energy reasonably into each stage in laser processing.