Flow Through Conical Converging Dies 通过圆锥会聚模的流动3.1. INTRODUCTION 3.1 引言3.1.1 The Subject 3.1.1 主题The study of metal flow through conical converging dies covers such processes as wire drawing, open-die extrusion, hydrostatic extrusion, and extrusion through a confined chamber. 金属流过圆锥会聚模的研究包括像拉丝、开式冷挤压、静液挤压和通过约束腔的挤压之类的工艺。Figure <1> represents a billet and die. 图1示出了一个毛坯和一个模具。The billet is made of an homogeneous isotropic material毛坯由一种均匀的各向同性材料制成; consideration will be given later to variable material properties.后面将对可变的材料性质给予考虑。 In the following simplification, the billet is a cylindrical rod of radius Ro; the rod is reduced to radius Rf by forcing it to pass through the conical converging die. 在以下的简化中,毛坯是一种半径为Ro的圆杆;该圆杆被迫通过圆锥会聚模而使半径缩小到Rf。Reduction is measured from the cross-section area of the billet at the entrance to the die (Ao) to that at the exit (Af). 半径的缩小通过模具入口处(Ao)到出口处(Af)的横截面积来衡量。Three variables involved in the reduction process are noted at once: 在缩径过程中涉及的三个变量马上就被注意到了:1. Reduction, which can be measured by the radius ratio Ro/Rf, the area ratio [(Ro / 2 2 Rf)], reduction in area: r = (Ao - Af) / Ao = 1 - Af / Ao = [1 - (Rf / Ro)], percent 2 reduction in area: r% = [1 - (Rf/Ro)]*100 or the effective or logarithmic strain: [Meff = 2*ln(Ro/Rf)] 1. 缩小量,它可以用半径比Ro/Rf;面积比[(Ro / 2 2 Rf)];面积的缩小:r = (Ao - Af) / Ao = 1 - Af / Ao = [1 - (Rf / Ro)];面积百分比2的缩小:r% = [1 - (Rf/Ro)]×100;或者有效应变或对数应变[Meff = 2*ln(Ro/Rf)]来衡量。2. The Semi-cone Angle, ("), half the die angle; in wire drawing " is relatively small, possibly 6E to 12E; open- die extrusion may employ an " = 60E; for extrusion through a closed chamber, the die may be square, namely with " = 90E. 2. 在拉丝中的半锥角(“),即模具的半角相对较小,可能在6E到12E; 开式冷挤压可能采用 “ =60E; 对于通过闭合腔的挤压来说,模具可能是方的,即具有” =90E。3. The third variable is friction between the die and the rod.3. 第三个变量为模具和坯料杆之间的磨擦。