Nano Tribology

Great Essays
Introduction:

Nano tribology is a study field of interfacial phenomenon in nano scale. The interaction between

two contacting solids during a relative motion from atomic to microscale is important to

understand the friction, wear, adhesion, indentation phenomenon. Now a days it has a plenty

application in micro electro mechanical system (MEMS), nano electro mechanical system

(NEMS), magnetic storage, lubricant manufacturing and many more field. There are few

instruments in the market to study the tribology , they are SFA, STM, AFM,FFM. Out of them

AFM is a powerful tool to study nano mechanics and nano tribology for its versatile nature in

imaging, roughness, nano scale force measurement to manipulation of tiny particle in nanoscale.
…show more content…
If we would do the scan in high speed then we have choose low stiffness material but

in case of low speed we should always choose high elastic moduli probe.

Adhesion force measurement: Adhesion force measurement can be done during recording of

the force vs displacement curve. This measurement has to be done in force calibration way. In

the below plot point A indicates that the distance between the tip and the sample is too high,

hence there is no interaction between sample and probe. After that, probe approaching the

sample surface and the distance between the probe and sample is decreases. Probe is now

coming towards sample and its now so close to the surface that is point B. Point C indicates that

probe is in contact with sample surface and the piezo goes beyond that so that the probe

deflected more. C-D indicates that the probe is in contact with surface and how sample starts

deforming by the applied probe force. Region D-E shows that probe is being withdrawn from

sample surface. Region D-F describe that the tip is being retracted. Just before this position
…show more content…
High stiffness probe is used to indent on any surface. During indentation

procedure a loading unloading curve will come that will describe the indentation depth amount

of indentation and many more elastic properties of samples. Depends on the sample, probe has to

choose. Generally diamond probe are using to indent very hard surface. The probe radius, half

cone angle, poison ratio of the materials all are required during calculation of young’s modulus.

We can clearly understand by comparing the before and after image of the indentation. After

indentation image will clearly shows the amount of area indented. Generally indentation

geometry cause non perpendicular tip-sample approach which result in significant lateral force

contributions during indentation. The spring constant of the cantilever and its geometry must be

well known to calculate the elastic properties. During nano indentation hardness measurement

the scan size has to be zero. Advantage of AFM indentation is its high depth and load

Related Documents

  • Great Essays

    Z= gives us the straining of the outer fiber. D= represents the depth of the beam. Z should be equal to 0.01 A plate with parallel grooves can be used to check the parallelism of the apparatus. Loading nose and supports would fit when it is properly aligned. A load has to be applied to the specimen at the specific crosshead rate and may take simultaneous load-deflection data.…

    • 1261 Words
    • 6 Pages
    Great Essays
  • Great Essays

    Cellulose Case Study

    • 2188 Words
    • 9 Pages

    Two limiting factors, i.e., cross-head speed and draw ratio were optimized to obtain the highest possible alignment of the nanofibrils during the hydrogel stretching. High cross-head speed and draw ratio typically lead to nanofibrillar fracture [ ]. Hence, the draw ratio and cross-head speed for largest inelastic deformation to align TBC in the stretching direction were optimized by conducting preliminary experiments. Figure 2 shows typical stretching behavior of TBC hydrogel at a cross-head speed of 0.03 mm/min. The optimum stretching of TBC hydrogel was obtained at a draw ratio of 1.2 without any initiation of fracture in TBC.…

    • 2188 Words
    • 9 Pages
    Great Essays
  • Improved Essays

    Stent Essay

    • 1686 Words
    • 7 Pages

    Due to low aspect ratio this method cannot be extended to stents of all designs. Thin film technology Stent manufacturing requires precision and tight tolerances which can be successfully achieved by this method. If the stents surface after manufacture is contaminated then it increases the clot forming tendency of blood. Thin film technology gives unadulterated surface finish which makes it a favourable method. .In radically high vacuum atmosphere sputters are deposited on planar or rotating substrate.…

    • 1686 Words
    • 7 Pages
    Improved Essays
  • Improved Essays

    If the contact surfaces are free from lubricant, then it is called dry friction. Otherwise it is called fluid friction. The friction is commonly controlled by kinematics of the surfaces in contact, external load, environmental conditions, texture of surface and properties of the materials. Figure 1.7 Friction force required to cause relative motion by (a) sliding (b) rolling 1.6.2 Mechanism of Sliding Friction Always the engineering surfaces are not perfectly smooth and flat. It has asperities (ie.,short range perturbations from the mean) and waviness (i.e., long range perturbations from the mean).…

    • 2169 Words
    • 9 Pages
    Improved Essays
  • Improved Essays

    Bending Strength Essay

    • 940 Words
    • 4 Pages

    The slope of the curve in the load-deflection graph will be as a result, the stiffness of the body (Malen 2011 p.124). Figure 44: H-point bending test convention (Malen, 2011) Bending Stiffness requirement Consider the body idealized as a simple beam loaded at its center span and the supporting points are in the suspension (Figure 45) as an analogy of H-point bending test of Figure 44. Figure 45: Simple supported beam for static test By applying the load, the body reacts in opposition to be bent. If this opposition is low, the distance of bending δ will be higher and consequently the bending angle α. This opposition depends on the wheelbase l and the section bending stiffness EI.…

    • 940 Words
    • 4 Pages
    Improved Essays
  • Great Essays

    Introduction The main objective of this lab is to observe the behavior of a metal block while experiencing uniaxial translation and oscillation in respects to time to calculate the acceleration, spring constant, and damping factor. The experiment was split into two different labs. Part one, the drop test, to take the block to a fixed height and drop it. This would then allow us to calculate the friction force, along with the acceleration of the metal block. Part two, the bounce test, is attaching the metal block to the spring, pushing the block down and releasing it.…

    • 2010 Words
    • 9 Pages
    Great Essays
  • Improved Essays

    The grippers differ from one application to another, so it is important to define the task clearly. Only by doing this, requirements for the design can be determined. This gripper will be used with robot in Institute for Plasma Research, RHRTD Division to develop a Mock-up platform for demonstration of Remote Handling tasks which will comprise of a robot and associated control system. The operation is mainly used during the maintenance period. Many-a-times this operations involves holding parts within tight enclosures, hence a two-fingered design is proposed which can access small areas along with simplicity of design compared to anthromorphic…

    • 879 Words
    • 4 Pages
    Improved Essays
  • Great Essays

    Rockbolts Essay

    • 1471 Words
    • 6 Pages

    The basic parts of a rockbolt are; the bolt, the keyhole plate, a nut, and a setting tool (Hartman & Mutmansky, 2002). The bolt must be tensioned with the correct force and set with the correct angle as calculated for the scenario (de la Vergne, 2008). The three main types of rockbolts are; mechanical bolts, resin bolts, and friction bolts (Hustrulid & Bullock). The mechanical bolts are mechanical point anchors which, when set in the predrilled hole, are then tensioned to secure an anchoring device which will pull against the keyhole plate and the anchor point to secure the surface to a more competent layer. The mechanical bolts have more parts to go wrong, as well as a higher cost.…

    • 1471 Words
    • 6 Pages
    Great Essays
  • Improved Essays

    Failure Mechanistics

    • 1636 Words
    • 7 Pages

    )〗^2/E πa=0 From the above equation, the stress can be written as: σf = √((2Eγ )/πa) It is important to note that Griffith’s original work was true for brittle materials, specifically glass rods. When a ductile material is considered, an accurate fracture model cannot be provided considering only the surface energy. Later on, Irwin and Orowan independently suggested that in a ductile material, the released strain energy was absorbed by energy dissipation due to plastic flow near the crack tip. Accordingly, the Griffith’s equation was modified…

    • 1636 Words
    • 7 Pages
    Improved Essays
  • Improved Essays

    Rockwell in 1922, these test procedures the depth of penetration as a substitute of the diameter of the indentation. The indenter is forced onto the surface, first through a minor load and then with a major load; the modification in the depths of diffusion is amount of the hardness of the material. Rockwell superficial hardness tests by means of the same kind of indenters, then at lighter loads, have also been established. Various features of the Rockwell hardness test can affect the measurement result. These comprise the purpose and standardization of separate components of the hardness machine, differences in the indenter, the testing sequence that is used, the testing atmosphere, the condition of the test material, and the operator.…

    • 1108 Words
    • 5 Pages
    Improved Essays

Related Topics