温习题.2012(国外英文资料).docVIP

复习题.2012(国外英文资料) 16. In the plastic forming friction compared with friction in mechanical transmission, has the following characteristics:,,, and the nature of the metal and tool differ big. 17. Metal and plastic processing, contact friction on the surface of the tool and block USES the following three assumptions:,, and. 18. Both ends closed slender thin-walled tube of the average diameter of r, average thickness of l, under internal pressure p and produce plastic deformation, a pipe isotropic, try to calculate the tangential and axial and radial strain increment ratio. Find the ratio of plastic strain increments in the following two conditions: (1) unidirectional stress state:; (2) pure shear stress state:. 4 - June 20. Introduction of rolling, extrusion and drawing When rolling, the metal flows easily to the entrance and flows less to the exit side, which is tilted towards the outlet side. Metal particle to the entrance to the lateral flow form, toward the exit side flow, to flow on both sides of the form. Rolling can be divided into three forms. Pipe rolling is usually used. Draw a simplified picture and accompany the text to illustrate how the HC mill increases the straightness of the strip, reducing the plate and the edges of the strip. Roughing is usually made of large rolling mill, while cold rolling mill is generally smaller in diameter, and try to explain the reason. In order to improve the thickness of plate and strip thickness, which method can be used to control the thickness? And briefly explain why. The extrusion process can be divided into three stages according to the characteristics of the metal and the change of pressure. The first stage becomes The second phase, called the basic squeeze phase, is called the third stage. 7. Extrusion die working zone is also called, is used to stabilize a key part of the products size and ensure that the surface. Name a few extruding tools, and make a brief explanation of their effect. What are the four bands of