粉末烧结坯冷轧时前滑与摩擦系数的确定

来源期刊：中南大学学报(自然科学版)1987年第1期

论文作者：曾德麟 周文标

文章页码：53 - 58

关键词：金属粉末； 板材； 冷轧； 前滑； 摩擦系数

Key words：metal powder； plates(materials)； cold rolling； forward slips； friction coefficient

摘    要：致密金属在理想轧制条件下.摩擦系数可由下式确定:μ=α/2[1-(4S_nh/Δh)^1/2 ]^-1 ,α是临界咬入角,S_n 是由实验测定的前滑值。Δh 为轧制压下量。本文根据有孔金属变形质量不变的原理,对上式进行修正,得到计算摩擦系数的新公式:μ=α/2[1-(4(S_n+1-K)h/KΔh)^1/2 ]^-1 ,K 是考虑:致密化的修正系数,它等于有孔金属轧制时,对应中性角的板坯密度与轧制带材的最终密度之比。该式也适用于致密金属轧制(K=1) ,因而是一个普遍公式。实验测定铜粉烧结坯冷轧的前滑值是随轧制板坯的原始密度增大而增大;按上式计算的摩擦系数则随轧带的密度增大而减小。

Abstract: Under an ideal roll-condition,the friction-coefficient of dense metals can be calculated by the formula as μ=a/2[1-(4S_nh/Δh)^1/2 ]^-1 ,where a is the critical angle of nip,S_n the forward slip determined experimentally and Δh the rolling reduction.Based on the mass constancy of the porous metal under deformation,in this paper,a modified formula for calculating the μ has been proposed,given by μ=a/2[1-(4(S_n+1-K)/KΔh)^1/2 ]^-1 ,where K is a modified index taking dinsification into account.The latter formula may be considered as an universal for it would be the same as the former(here K exactly becomes 1) when used to the dense metals.The values of forward slip were measured experimentally on copper powdersintered blanks and the μ was then obtained from the above formula.The forwardslip increases in magnitude with the increase of the initial densities of the blanks but the μ decreases with the increase of the density of sheets.