Table of Contents
How do you calculate specific wear rate?
wear rate=(wear amount)/(sliding distance or time) (m/m, m3/m, kg/m, m/s, m3/s, kg/s). wear coefficient, or specific wear rate (also sometimes called wear factor) = (wear rate)/(normal force) (m3 N−1m−1).
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).
What is the relation between rate of wear and constant surface area?
What is the relation between rate of wear and contact surface area? Explanation: If any surface has large number of irregularities i.e. hills and valley then the surface will obtain good bearing properties. Rate of wear is proportional to the load per unit area and surface area in contact.
What is the unit of wear coefficient k )?
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 do we measure wear?
Wear Rate and Volume The specific wear rate for any material can be calculated using the measured average depth during each scratch. Wear rate, k, has most physical relevance when reported as volume loss per unit normal force per unit sliding distance . This shows the loss of material occurred by the wearing.
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 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.
What are the different types of wears?
There are four basic types of wear: adhesive, abrasive, corrosive, and surface-fatigue.
What is abrasive wear in gear?
Abrasive wear is another form of gear wear in which hard particles slide and roll under pressure, causing cutting. Hard particle sources may include metal particles from gear teeth and particles being introduced into the housing, such as casting dirt and scale.
Does wear rate increases with increasing load?
Generally, wear rate due to time increased linearly and linear wear resistance decreased with increasing loads. However, the wear rate was directly proportional to the load up to a critical load of 7 N. The wear rate due to time increased slightly as the sliding speed increased in the range 0.09-0.90 m/s.
Which of the following is true about Tomlinson surface meter?
Which of the following is true about Tomlinson surface meter? Explanation: The Tomlinson surface meter uses mechanical cum optical means for magnification. It has a diamond stylus on the surface finish recorder. This instrument is given reliable results.
Which of the following method is used for the determination of flatness when the surface is irregular?
5. Which of the following method is used for the determination of flatness when the surface is irregular? Explanation: When the surface is irregular, contact method of testing for flatness is used. Explanation: Straight edges can be used to test flatness and straightness of the surfaces.
What are tribological properties?
Tribology is the science of wear, friction and lubrication, and encompasses how interacting surfaces and other tribo-elements behave in relative motion in natural and artificial systems. This includes bearing design and lubrication.
Who is father of tribology?
Leonardo da Vinci (1452-1519) has been named as the father of modern tribology as he was the first who studied an incredible manifold of tribological subtopics such as: friction, wear, bearing materials, plain bearings, lubrication systems, gears, screw-jacks, and rolling-element bearings.
How is wear test conducted?
The wear tests were carried out on a pin-on-disc tribometer, placed in a magnetic field applied perpendicularly to the sliding surface, in an ambient environment (Fig. 1). The disc with 50 mm in diameter was rotated by an electrical motor. The pin was a cylinder with 10 mm in diameter and 20 mm in length.
Why wear test is done?
ABSTRACT: Wear tests are performed for a variety of reasons: to gain an under- standing of the wear process, to determine the effects of variables, to characterize materials, and to select materials for specific applications. The development of a standard wear test is considered to be urgently needed.
What is material wear?
Wear is a process that involves the interactions between surfaces and, more specifically, the removal and deformation of material from a surface as a result of mechanical action of the contacting object through motion.
What is the mechanism of wear?
Wear is the removal of the material from the surface of a solid body as a result of mechanical action of the counterbody. Wear of Engine bearings is the removal of the bearing material from its surface caused by sliding friction between the bearing and the crankshaft.
How is tear resistance measured?
Tear resistance can be measured by the ASTM D 412 method (the same used to measure tensile strength, modulus and elongation). Tear resistance is then calculated by dividing the force applied by the thickness of the material.
What makes a material wear resistant?
Surface Hardness and Wear Resistance If the hardness of the material is higher than that of the abrasive material, less wear rate will occur. Case hardening or surface hardening is the process in which hardness the surface (case) of an object is enhanced, while the inner core of the object remains elastic and tough.
What is sliding distance in wear test?
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.
