Preparation And Mechanical Characterization Of AlMgB Thin Films By Magnetron Sputtering

As one of the new superhard films,AlMgB thin films have broad application prospects in industry.In this paper,AlMgB thin films were prepared by high vacuum three-target magnetron sputtering system under different B target power,different bias voltage-duty ratio composite parameters and frequency to optimize the preparation process of thin films.AlMgB thin films were prepared at different B target power.The experimental results show that AlMgB thin films are amorphous.With increasing B target power,the deposition rate of AlMgB thin films increases gradually,and the maximum value is 6.4nm/min.The root mean square surface roughness of AlMgB films decreases first and then increases with the power of B target.When the power of B target is 400W,the minimum RMS roughness is 0.32nm,reaching the atomic level of smoothness.Adjusting the power of target B to 600W,the content of B₁₂ icosahedron in the film is the highest.At this time,the mechanical properties of the film are the best.The hardness and modulus of elasticity are 23GPa and 250GPa,respectively.AlMgB thin films were prepared at different composite parameters of bias voltage and duty cycle.The experimental results show that the deposition rate of AlMgB films decreases with the increase of bias voltage at the same duty cycle.Under the same bias voltage,deposition rate of the thin films increases with decreasing duty cycle.The surface roughness of the thin films varies nonmonotonically with the change of bias-duty ratio composite parameters.The results show that when the bias-duty ratio composite parameters are 20%-100V,the surface of the films reaches atomic level smoothness,and the surface RMS roughness is 0.38nm.AlMgB thin films exhibit the best mechanical properties when the bias-duty ratio composite parameters are 10%-300V.At this time,the hardness（H）and modulus of elasticity（E）of the films are 38.1GPa and 334GPa respectively,and the content of B₁₂ icosahedron is the highest in the thin films.AlMgB thin films were prepared at different pulse frequencies.The experimental results show that with the increase of pulse bias frequency,the deposition rate of AlMgB thin films decreases,the content of B₁₂ icosahedral in the films increases first and then decreases.And the mechanical properties increase with the increase of pulse bias frequency.When the pulse frequency is 60KHz,the hardness and modulus of elasticity of AlMgB films reach the maximum value:37.4GPa and 328GPa respectively.