CAJ | 학술논문

考虑到金属材料热导率、弛豫时间、电子-晶格耦合系数等热力学参数随温度非线性变化因素的影响,运用具有人工粘性和自适应步长的有限差分算法,数值求解了飞秒激光辐照金属薄膜的超快热弹性模型,分析了飞秒激光辐照200nm铜膜时温度场和应力场的变化规律.结果表明:电子热导率和电子-晶格耦合系数对温度场变化有较大影响;在超快加热早期,热电子崩力在金属薄膜表面附近迅速达到峰值,后期急剧减小的热电子崩力和逐渐增大的晶格温度梯度共同决定了薄膜体系中应力场的变化.
고필도금속재료열도솔、이예시간、전자-정격우합계수등열역학삼수수온도비선성변화인소적영향,운용구유인공점성화자괄응보장적유한차분산법,수치구해료비초격광복조금속박막적초쾌열탄성모형,분석료비초격광복조200nm동막시온도장화응력장적변화규률.결과표명:전자열도솔화전자-정격우합계수대온도장변화유교대영향;재초쾌가열조기,열전자붕력재금속박막표면부근신속체도봉치,후기급극감소적열전자붕력화축점증대적정격온도제도공동결정료박막체계중응력장적변화.
Considering of the temperature effects on the thermal conductivity, relaxation time and electron-lattice coupling coefficient, the ultrafast thermoelasticity model for metal films heated by femtosecond pulse lasers has been solved by the finite-difference method with viscosities and adaptive time steps. The variation law of temperature field and stress fields are analyzed in 200nm copper film. The numerical results indicate that the electron thermal conductivity and electron-lattice coupling coefficient have a great impact on the change of temperature field. The hot electron blast force near the irradiated surface quickly reach the maximum in the early period, then the hot-electron blast force falling rapidly and lattice temperature gradually increasing lead to the change of stress field.