TJ467 : Investigation of the effect of die manufacturing operation on the forging process tribology
Thesis > Central Library of Shahrood University > Mechanical Engineering > MSc > 2017
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Abstarct: In the forging process, the texture of the die surfaces, affected by die making method, plays a significant role in the contact surface tribology. The slip on the surface of the mold depends on the surface roughness and its orientation. Therefore, the coefficient of friction and contact forces directly affects the surface texture. In the present study, the effect of different methods of forging die manufacturing, in two dry and lubricated conditions has been investigated for ck45 steel by ring compression test. For this purpose, the forging die was made by six machining methods i.e. horizontal and vertical milling, EDM, grinding, grinding as along with polishing and turning and then the ring-shaped specimens ratio 6: 3: 2 were subjected to the compression test by these molds. Circular samples were rotated by a 12 mm machine and then drilled with a 6 mm internal diameter. After cutting, two flat surfaces of the ring were stamped to reach 4 mm. In this research, the effect of two parameters of machining method and lubrication mechanism on the coefficient of friction and surface roughness were investigated. To investigate the effect of parameters and optimize them, the necessary experiments were designed using a full-factorial design scheme. By performing the tests according to the design, the values of the functions of the coefficient of friction coefficient and surface roughness were extracted. The results show that machining is the most effective parameter affecting the coefficient of friction and surface roughness. Using die insert made by four machining methods of horizontal and vertical milling, EDM and turning, although the inserts had the same roughness, the different coefficient of friction was obtained. This is due to the different forms of surface texture. In the forging by completely smooth die surface i.e. ground and polished die, the lubrication has no meaningful effect on surface roughness of forged specimens. Increasing the strain caused by an increase of height reduction percent in the ring compression test results in an increase in surface roughness in both dry and lubrication conditions.
Keywords:
#Tribology - Die forging - Machining –Ring compression test Link
Keeping place: Central Library of Shahrood University
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Keeping place: Central Library of Shahrood University
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