Crushing Mech Anism Of Poly Silicon And Design Of Crushing Device

Polycrystalline silicon is an important foundation of photovoltaic industry and semiconductor industry.It is the raw material for making solar cells and electronic silicon chips.Its purification process mostly uses repeated crushing and roasting,among which the over crushing phenomenon in the crushing process is easy to lead to excessive waste of materials.At present,the industry mostly adopts the artificial percussion crushing method.According to the urgent needs of enterprises,this paper puts forward an automatic crushing method for the problems of material waste and low efficiency,and optimizes the design of automatic polysilicon crushing device,mainly for the primary crushing of polysilicon rod and cut polysilicon plate,trying to reduce the proportion of over crushing and the number of re crushing.The main research contents include:First of all,the mechanism of cracks in polysilicon under impact is analyzed,and the relationship model between the threshold value of accumulated damage of polysilicon under load and the crystal dislocation and microcrack of polysilicon is established.Secondly,based on AUTODYN software combined with polysilicon material model and brittle material damage model,the crack generation and propagation process of polysilicon under the impact of hammer head is simulated.The results show that when the center of polysilicon plate is knocked,the distribution of cracks is relatively uniform,and the particle size of fragments is moderate;when the polysilicon rod is knocked at the knocking speed of 2.5m/s,the over smashing proportion is the smallest(the number of fragments less than 20mm is small);the impact of different hammer shape on cracks is analyzed.Finally,based on the vision device and mechanical arm,the bionic automatic percussion device is realized,and the key parts are analyzed and optimized.Through a large number of percussion experiments,the statistical analysis shows that when the percussion speed is 2.5m/s,the proportion of fragments smaller than 20 mm is 4.32%,which is smaller than other forms of crushing,meeting the application requirements of enterprises.