Analysis Of Characteirstics Of Acoustic Signal From Mould Laser Bionic Strengthening Unit

Because hot work die touches repeatedly with high-temperature material inservice time and happen fatigue by chronically alternating stress role, so mouldlocal surface produces crack and strength is destroyed, which affects the servicelife of die. More and more attention to environmental protection and savingenergy and resource, recently, many scholars debate on the laser bionicstrengthening surface of mould. Mould laser bionic strengthening technology caneffectively prolong service life of the die and save the expensive cost of patterndrawing owing to improving micro chemical and organizational composition ofthe mould surface, and enhancing the wear resistance, hardness and fatigueresistance. So it will greatly reduce the cost of produc, cut the production cycleand bring significant economic benefits. Therefor, in the paper, the mouldsurface laser bionic strengthening technology and detection of laser meltingbionic unit quality on mould surface based on acoustic signal which is mainlyanalysised. To sum up, the specific work is followed for this paper.It is constructed mathematics model of local laser bionic blocking cracks forestimating the life of unit. And then, it is confirmed the feasibility of laser bionicstrengthening. Combining with the mathematics model, we could find out theoptimal group of laser processing parameters by orthogonal experimental design.The unit has with antiblocking effect by analysis of micro structure andmicrohardness the optimal unit. The acoustic signal of the manufactured laserbionic strengthening unit is denoised and then processed by WaveletTransformation (WT) or Hilbert—Huang Transform (HHT), which can clearlydistinguish the difference to strengthening quality. Theoretically, the HHT coreconcept is instantaneous frequency. The instantaneous frequency is derived bydifferentiating with Hilbert Transform (HT) phase function. Only can HHT accurately bring the frequency rules with time without false and redundantfrequency. Bringing the more intuitive and specific nonlinear acoustic signal,HHT can point out error operating owing to repeatability operation. So that itcould reduce the number of inferior strengthening stripe (unit) and increase theservice life of die.