Name :Hemamalini Rawindran
Group: ACB (A2)
1.0 Wear
In materials science, the terminology wear simply means, the disintegration of material from a solid surface by the movement of another solid. Wear may result whenever there is sliding. A potential wear situation occurs when there is relative motion between two solids under load. Motion can be unidirectional or reciprocating either sliding or rolling. There may be a combination of rolling and sliding of wear which may occur due to oscillary movement at small amplitudes. The investigation of the techniques of wear is some piece of the control of tribology.
Depending on the nature of the movement or of the media involved in an interaction under load, the following types of wear have been classified;
1. Adhesive wear
2. Abrasive wear
3. Corrosive wear
4. Surface fatigue
There are few types of wear mechanisms that can be found in automobile components. The components that are involved includes the accumulator, rolling bearings, piston rings, brake pads, gears and etc whereby different type of wears can be identified from each components.
2.0 Wear materials in automobiles
2.0.1 Ball and roller bearings
The ball and roller bearings is made up of several components such as two rings, rolling bodies, a cage (steel or bronze) to separate and guide the rolling balls, lubrication(oil or grease), protection (steel baffle) that is always lubricated. There are three types of roller bearings such as cylindrical, taper and spherical bearings.
Rolling, compared to sliding requires less effort and rolling bearings give the some order of low friction as encountered under fluid film lubrication in journal bearings. In a typical assembly, the shaft is fixed to the inner race which rotates whi...
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...st a more reactive counterface , as in steel bearing, the slight decomposition of the IL is caused at times due to the reaction with iron. However, IL can be still used as a lubricant in bearing because it is a highly performing lubricant that still plays part in improvement of corrosion level.
3.0 Conclusion:
Mechanical wear of bearings could be of varieties right from structures like abrasion and fretting to extreme structures, like smearing and skidding relying on the working conditions. Analysis of bearing damage observed under the scanning electron microscope aids in recognizing the mechanism and kind of wear. This further supports in building the cause of wear. The complete modification eventually is suitable in restorative measures of bearing. Subsequently the operational proficiency is ensured and life of different types of bearings could be enhanced.
As the ball bearing accelerates the friction acting against the falling ball bearing increases which in turn balances out the forces applied to the ball bearing which reaches the terminal velocity.
Fatigue failure can be divided in three parts i.e. Crack initiation, Crack propagation and Final rupture.
They use a special kind of rubber called butyl rubber. A machine helps to write on the balls to put the letters on it. Some balls are made with higher quality thread.
These globules act as a lubricant, decreasing the friction coefficient between the tools and the materials by creating discontinuities of chip fragmentation. Therefore, it reduces cutting force and then, the tool wear rate is minimized [13]. Different alloying elements help to improve the machinability are usually added to brass. The most common element used in this situation is lead, which improves the machinability with excellent chip breakage, low tool wear and high applicable cutting parameters. These aspects can be explained by two basic phenomena; in the first, the solubility of lead in brass is extremely low and lead segregates in the entire microstructure, particularly at the grain boundaries.
Foam rollers are made of cylindrical type of equipment used in both physical therapy and exercise.
At low cutting conditions attrition was found dominant wear mechanism of cemented carbide cutting tool.
wear smooth, certainly the machine will wear out. If the injustice has a spring, or a pulley, or a rope, or a
Mechanical Engineering 130.2 (2008): 6 - 7. Academic Search Complete. Web. The Web. The Web.
Brakes may be one of the most essential inventions in the developments of automobiles. Clearly, nothing can surpass the breakthrough of the wheel, but the brake system was a catalyst to the further developments of cars. The brake system has also evolved greatly throughout the years. Once considered one of the simplest parts of a vehicle, brakes have become one of the most complicated components in a vehicle. The scientific explanation behind a brake system is very rudimentary. Friction permits the concept of braking to occur.
In short brakes are a tool that turn kinetic energy into heat(http://en.wikipedia.org/wiki/Brakes). This is accomplished by applying friction in one way or another. In the case of disk brakes friction is created because the braking mechanism exerts a force on the break pads which pushes them into contact with disk. It is this contact combined with the fact that the disks are rotating that causes kinetic energy to be converted to heat.
Typically the lubricant-to-surface friction is much less than surface-to-surface friction in a system without any lubrication. Thus use of a lubricant reduces the overall system friction. Reduced friction has the benefit of reducing heat generation and reduced formation of wear particles as well as improved efficiency. Lubricants may contain additives known as friction modifiers that chemically bind to metal surfaces to reduce surface friction even when there is insufficient bulk lubricant present for hydrodynamic lubrication, e.g. protecting the valve train in a car engine at startup.
Corrosion is by far the greatest concern when it comes to aging aircraft. Corrosion is a deformity that occurs at the surface and subsurface of the structure and components of aircraft. This creates a greater need for advance techniques and inspections used to detect these deformities. Some techniques talked about in this paper that are used to detect corrosion are non-destructive testing, and different scheduled inspections.
In a world that is quickly becoming ever dependant on technology, people take many things for granted. For example: nearly every day you and I get into our cars to go to work, school, shopping, or anywhere else you can think of. Naturally, car manufacturers are constantly coming up with new technologies to get people to buy their car over the next manufacturers; and a lot of these new inventions seem straight out of a sci-fi movie, or book in this case.
Magnetic bearings can be broken down into two different categories depending on what type of application it will be implemented in: passive magnetic bearings and active magnetic bearings. Passive magnetic bearings use permanent magnets, which allow the the shaft to hold the position through the center of the bearing without the necessary use of electrical input power. These permanent magnet are placed around the inside of the cylindrical bearing to make sure the shaft levitates freely without the help of surface friction. The advantage is that these magnets are able to keep the shaft in equilibrium without the help of external electricity. The problem that the passive magnetic bearing faces is that it is very difficult to design these types of permanent magnetic bearings because of limitations in the actual permanent magnet. The limitations are that since there is no need for external electricity in a permanent magnet, that actual lack of it makes it hard to create an assemblage of point charges that buil...