| The good life of 5G is coming soon,and it puts forward higher requirements for the stable work of communication base stations and smart devices.It is important to study high-strength and high-conductivity casting alloys to provide a stable working environment for communication base stations and smart devices.Cast aluminumsilicon alloy has good thermal conductivity and mechanical properties,and is very suitable for large-scale application of communication products.Si phase morphology,changed by controlling Si content,modification treatment and solution treatment is characterized by scanning electron microscope.The influence of Si phase morphology on the comprehensive properties of the alloy was analyzed,and the influence principle of Si on the heat conduction of Al-Si alloy was studied.By analyzing alloys after annealing and T6 heat treatment,the effects of heat treatment on the overall properties of the alloy were analyzed.The conclusions are as follows:(1)In the Al-Si alloy,the Si phase increases with the Si content,and the Si phase morphology consists of a discrete distribution of low Si content,a lamellar distribution of near-eutectic components,and a massive primary Si of hypereutectic.When the Si content is increased from 2wt%to 6wt%,the thermal conductivity of the alloy is rapidly decreased from 182.37W/mK to 168.66W/mK,and when the Si content is 815wt%,the thermal conductivity of the alloy is maintained at about 163W/mK.The hardness of the alloy increases with increasing Si content,increasing from 39.1HV to 71.2HV.When the Si content is 10 wt%,the overall performance is good,the alloy hardness is 54.42HV,and the thermal conductivity is 163.79W/mK.(2)After the alloy is modified by Sr,the eutectic Si structure changes from a coarse sheet to a fine coral.The hardness and thermal conductivity of the alloy are improved compared to before the deterioration.After the modification of Al-10Si alloy,the hardness increased by 26%to 68.60HV,and the thermal conductivity increased to 170.23 W/mK.(3)After the solution treatment,the eutectic Si phase is melted,spheroidized,and grown.The hardness of the alloy decreases with the increase of solid solution time.When the Sr metamorphic Al-10Si alloy is dissolved for 3h,the hardness of the alloy decreases by 7%,but the thermal conductivity of the alloy increases by 10%to reach 187.06W/mK,and the thermal conductivity of the alloy It increases with increasing solid solution time.(4)The thermal conductivity of Al-Si alloy is greatly affected by the morphology of Si phase.The coarse Si phase hinders the movement of free electrons in the alloy,increasing the mean free path of electron motion,thereby reducing the thermal conductivity of the alloy.The Si phase can be effectively refined by the modification treatment,and the solution treatment can spheroidize the Si phase,effectively reduce the hindrance of Si relative to free electron motion,and improve the thermal conductivity of the alloy.(5)After the addition of 0.35Mg and 0.65Fe to the Al-10Si alloy,the as-cast alloy has a thermal conductivity of 158.89 W/mK and a tensile strength of 217MPa.The thermal conductivity of the alloy is achieved by a short annealing treatment at 180?/60min.157.98W/mK,tensile strength increased by 15%.(6)After heat treatment of T6 at 535?/4h and 180?/9h,the comprehensive performance of Al-10Si-0.35Mg-0.65Fe alloy was greatly improved,the thermal conductivity reached 179.36W/mK,and the tensile strength reached 301.49MPa. |
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