The validity of a novel, direct and convenient method for micromechanical property measurements by beam bending using a nanoindenter is demonstrated. This method combines a very high load resolution with a nanometric ...The validity of a novel, direct and convenient method for micromechanical property measurements by beam bending using a nanoindenter is demonstrated. This method combines a very high load resolution with a nanometric precision in the determination of the microcantilever beam deflection. The method is described clearly. In the deflection of microbeams, the influence of the indenter tip pushing into the top of the microbeams and the curvature across its width must be considered. The measurements were made on single-layer, micro-thick, several kinds of width and length polysilicon beams that were fabricated using conventional integrated circuit (IC) fabrication techniques. The elastic of a polysilicon microcantilever beam will vary linearly with the force and the deformation is thought to be elastic. Furthermore, it suggests that Young modulus of the beam can be determined from the slope of this linear relation. From the load deflection data acquired during bending the mechanical properties of the thin films were determined. Measured Young modulus is 137 GPa with approximately a ±2.9%～±6.3% difference in Young modulus.展开更多
The naniondentation fracture of multilayer hard coatings, such as TiN, TiN/Ti(C, N)/TiC, TiN/Ti (C,N)/TiC/Ti (C, N)/TiC and TiN/Ti (C, N)/TiC/Ti (C,N)/TiC/Ti(C,N)/TiC coating, deposited on cemented carbide using a CVD...The naniondentation fracture of multilayer hard coatings, such as TiN, TiN/Ti(C, N)/TiC, TiN/Ti (C,N)/TiC/Ti (C, N)/TiC and TiN/Ti (C, N)/TiC/Ti (C,N)/TiC/Ti(C,N)/TiC coating, deposited on cemented carbide using a CVD technique are studied. It is found that these coatings have high hardness. Based on the analysis of the energy release in cracking, the fracture toughness of these coatings are calculated. The observations clearly establish a step occurs in the force-displacement curves at the onset of coating fracture and a straight line segment in the load-penetration depth squared curves to idenntify the interfacial failure of coatings. The hardness, fracture toughness and anti-wearability of these coatings are clearly compared. The results show that with the layers increasing, the fracture toughness and anti-wearbility are getting larger.展开更多
The basic lubrication equations are used to calculate two kinds of lubrications examples,a plane inclined slider and a journal bearing respectively. In the calculation of the journal bearing,the Reynolds’ boundary co...The basic lubrication equations are used to calculate two kinds of lubrications examples,a plane inclined slider and a journal bearing respectively. In the calculation of the journal bearing,the Reynolds’ boundary conditions are used. In the calculation, it is found that the load carryingcapacities of the slider and the journal are of different tendencies with increase in Deborah number.Furthermore, the results show that with decrease in the film thickness the increase in the normalstress of second-order fluid is greater than that of Newtonian fluid. Finally, it is found that the dis-tribution of the normal stress changes significantly at a certain thickness.展开更多
文摘The validity of a novel, direct and convenient method for micromechanical property measurements by beam bending using a nanoindenter is demonstrated. This method combines a very high load resolution with a nanometric precision in the determination of the microcantilever beam deflection. The method is described clearly. In the deflection of microbeams, the influence of the indenter tip pushing into the top of the microbeams and the curvature across its width must be considered. The measurements were made on single-layer, micro-thick, several kinds of width and length polysilicon beams that were fabricated using conventional integrated circuit (IC) fabrication techniques. The elastic of a polysilicon microcantilever beam will vary linearly with the force and the deformation is thought to be elastic. Furthermore, it suggests that Young modulus of the beam can be determined from the slope of this linear relation. From the load deflection data acquired during bending the mechanical properties of the thin films were determined. Measured Young modulus is 137 GPa with approximately a ±2.9%～±6.3% difference in Young modulus.
文摘The naniondentation fracture of multilayer hard coatings, such as TiN, TiN/Ti(C, N)/TiC, TiN/Ti (C,N)/TiC/Ti (C, N)/TiC and TiN/Ti (C, N)/TiC/Ti (C,N)/TiC/Ti(C,N)/TiC coating, deposited on cemented carbide using a CVD technique are studied. It is found that these coatings have high hardness. Based on the analysis of the energy release in cracking, the fracture toughness of these coatings are calculated. The observations clearly establish a step occurs in the force-displacement curves at the onset of coating fracture and a straight line segment in the load-penetration depth squared curves to idenntify the interfacial failure of coatings. The hardness, fracture toughness and anti-wearability of these coatings are clearly compared. The results show that with the layers increasing, the fracture toughness and anti-wearbility are getting larger.
文摘The basic lubrication equations are used to calculate two kinds of lubrications examples,a plane inclined slider and a journal bearing respectively. In the calculation of the journal bearing,the Reynolds’ boundary conditions are used. In the calculation, it is found that the load carryingcapacities of the slider and the journal are of different tendencies with increase in Deborah number.Furthermore, the results show that with decrease in the film thickness the increase in the normalstress of second-order fluid is greater than that of Newtonian fluid. Finally, it is found that the dis-tribution of the normal stress changes significantly at a certain thickness.
