A desirable Nano crystallization of surface by shot peening on Metallic Parts |
Paper ID : 1575-UFGNSM-FULL |
Authors: |
Amir valla Azad University, Research unit |
Abstract: |
Abstract When severe plastic deformation is implied on metals and alloys, their grains are broken to very smaller grain size. These grains are in the nano scales [22]. Shot peening; 1) will increase hardness of metal significantly, 2) will increase wear corrosion resistance of metals in most pH and 3) will increase fatigue life up to 20%. Shot peening has many parameters which has to be taken into consideration in order to make a nanocrystalline surface. The first one is a good selection of instrument. Shot peening Machines are classified by the way they distribute energy to the peens. Some of which are: 1- Air blast or air shot peening 2- centrifuge shot peening 3- Ultrasonic shot peening. For obtaining the same result in shot peening there shoud take into the consideration the type of instrument which are selected and the accepted standards. The parameters in shot peening which must be taken into consideration for making the nano crystallization of the surface are : 1)intensity, 2) pecent of coverage, 3) size of peens and their materials, 4) angel of shot flow, 5) time of shot peening, 6) hardness of peens. In this research, these variables were determined for good nanocrystallization of surface. The calibration of intensity Acc. to Almen strip and percent coverage is done by drawing the time intensity curve for each shot peening machine. The number of passes or time of being in the chamber of shot peening machine is another important parameter. . |
Keywords: |
Severe plastic deformation, nano surface, size of pin, intensity, percent coverage, time of shot peen |
Status : Paper Accepted (Poster Presentation) |