How do you calculate material wear?
A wear factor is calculated with the equation W=K*F*V*T. In this equation W is wear volume (mm3), K is wear factor (mm3/N m)10-8, F is force (N), V is velocity (m/sec), and T is elapsed time (sec).
How is sliding distance calculated?
The sliding distance s can be replaced by s=v.t where v is the mean value for the slide rate and t the running time. Because the k-value depends just like the friction coefficient on a lot of parameters this factor is to be find experimentally.
How do you quantify wear resistance?
Pin-on-disc measurement involves engaging an indenter or pin (usually flat or sphere shaped) on to a test sample. The engagement mechanism applies a precise force to the indenter as the test sample is rotated. The resulting friction forces are measured using a strain gage sensor.
What is the abrasive wear?
Abrasive wear occurs when a hard rough surface slides across a softer surface. ASTM International defines it as the loss of material due to hard particles or hard protuberances that are forced against and move along a solid surface. Three commonly identified mechanisms of abrasive wear are: Plowing.
How do we measure wear?
There are two main methods to measure tool wear: indirect and direct methods. In the indirect method, tool wear is estimated with the signals coming from different types of sensors such as surface texture of machined workpiece, acoustics, vibration, feed forces, and current consumption [1–5].
What is the sliding distance?
The sliding distance can be calculated as the linear speed times the duration of the test. In the case of a reciprocating test you can find the sliding distance as the frequency(f) times the duration of the test(t) time wear track length (wtl), or SD=f*t*wtl.
What are the different types of wear?
There are four basic types of wear: adhesive, abrasive, corrosive, and surface-fatigue.
What are the two types of abrasive wear?
The abrasive wear to be verified was of two types: two-body abrasive wear and three-body abrasive wear. Two-body abrasive wear is caused by rubbing of a softer surface by a hard rough surface while three-body abrasive wear is caused by hard particles entrapped between two sliding surfaces (4).
How do you stop abrasive wear?
The most common techniques is to use wear resistant materials or simply by changing the material properties, e.g. by hardening. Wear can also be prevented by keeping the surfaces apart from each other. Oil and grease are commonly used for this purpose. A third method is to design for reduced wear.
How is the state of abrasive wear determined?
The shape of the abrasive particle, the hardness, the load and the shear strength at the contact interface determine the state of the abrasive wear . The abrasive wear coefficients of metals are in the range of depending on the conditions, which is larger compared to adhesive wear . Thus, abrasive mode is mainly a severe type of wear.
How is the value of an abrasion measured?
This value shall be reported as the percentage of wear. Difference between the original weight and the final weight of the test sample shall be expressed as a percentage of the original weight of the test sample. This value shall be reported as the percentage of wear.
How is K used to measure abrasive wear?
Then K can be defined for abrasive wear as work done to create abrasive wear particles by cutting is more useful; this is known as the dimensional wear coefficient or the specific wear rate. This is usually quoted in units of mm 3 N −1 m −1.
How to calculate the wear rate of a surface?
A common used equation to compute the wear rate is (Archard,1953). V i =k i F s. where F is the normal load, s the sliding distance, V i the wear volume and k i the specific wear rate coefficient. Index i identifies the surface considered.