Study On Mechanical Characteristics And Heat Transfer Characteristics Of Thermal Flying Control Head Disk Interface

Hard disk drive(HDD)is widely used for its large storage,running speed and high security performance.In order to obtain higher magnetic recording density,the gap between head and disk(also named Flying Height,FH)is getting smaller,and now the FH has been decreased to several nanometers.By using TFC(Thermal Flying Control)technology,the thermal expansion of head slider can be realized when the head is heated,thus decreasing the FH of head and ensuring flying stability.The numerical analysis steps of the thesis are: 1)establish a geometric model of the TFC slider with a heater,extract the data of the deformation and temperature of the slider under the influence of the heater;2)use the finite element method to solve the Reynolds equation with the LFR model and heat transfer energy equation are used to obtain the pressure distribution and temperature distribution data of the magnetic disk;3)Study the influence on the pressure distribution and heat transfer when the gas between the gas films is a helium-air mixed gas.The simulation results show that the heater position height,heater length,height and the heater power all have a large effect on the deformation and temperature,but the thickness of the heater has a weak effect on the deformation and temperature of the magnetic head slider.Changes in disk speed,ambient pressure,heater length,height,and power all have an effect on the pressure and temperature of the disk surface,but the pitch angle has a small effect on the pressure and temperature of the disk surface.Helium has the advantages of good thermal conductivity and easy storage.It is more suitable for filling hard disks than air,and can effectively reduce the vibration of the magnetic head slider.However,helium also has the disadvantages of being difficult to obtain and expensive,and hard disks charged with pure helium are expensive.In order to balance the flight characteristics and cost of the hard disk,filling the hard disk with a mixedgas of helium and air also has the advantage of filling the hard disk with pure helium.Under the influence of the gas film of mixed gas with different helium volume ratios,the effects of different helium content on pressure and heat transfer under different environmental pressures,disk rotation speeds,and heater power were compared.Ambient pressure,disk speed,and heater power all cause changes in helium content to affect the maximum pressure and head-disk temperature difference.