机械合金化对fecu复合粉末固相烧结及性能的影响

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1、摘要本文针对金属结合剂金刚石上具中Fe、Cu粉末圃相烧结中可烧结性差、可控工艺范围窄，烧结不稳定的现象，提出采用机械合金化技术改善Fe．Cu复合粉末固相烧结性能，提高Fe基结合剂金刚石工具使用性能。本文通过对不同球磨时间Fe—Cu复合粉术的研究，分析了Fe．Cu复合粉末在机械合金化过程中颗粒度、晶粒度、晶体结构、粉术成分均匀化程度以及粉末储能的变化。通过对烧结后胎体金相组织结构、密度、硬度、抗弯强度的研究，分析了机械合金化过稗对Fe．Cu复合粉术固相烧结的影响。实验结果表明，通过机械合金化处理，Fe—Cu复合粉术粒度减小、晶粒细化、成分均匀化程度提高，粉末中

2、积聚了大量的表面能、界面能、畸变能等能量。在球磨30h后，Fe．Cu复合粉末在加热到940。C时放热1809．20J／g，是未进行机械合金化的粉体放热量(65．62J／g)的27．5倍。900℃下烧结后，胎体金相组织细腻，组分均一，结合良好，其密度、硬度、抗折强度分别提高了9．7％、84．6％和51．2％，金刚石刀头磨削性能显著提高，球磨30hFe—Cu复合粉末制得的金刚石刀头与未经机械合金的金刚石=JJ头相比，其磨耗比提高了近5倍。以上结果说明，机械合金化显著促进了Fe．Cu复合粉术的固相烧结，改善了烧结后胎体的性能，大幅度提高了金刚石刀头的磨削性能。关键

3、词机械合金化；复合粉术；储能；固相烧结：金刚石刀头燕山大学工学硕士学位论文Abs仃actInordertosolvetheproblemsofthesolidstatesinteringbetweenCuandFe(suchashard-to—sinter,narrowcontrollabletechnology,instabilityofsintering)，whichwerethemainelementsofmetallicbinderdiamondproducts，mechanicalalloying(MA)wasintroducedtoimprove

4、thesolidstatesintercharacterofFe-Cucompoundpowdersandtheperformanceoftheiron·-basebinderdiamondproducts．11hechangeoftheparticlesize，grainsize，crystalstructure，homogeneitydegreeofthepowderscomponentsandthestoredenergyintheprocessofMAwasanalyzedbyinvestigatingthecompoundpowdersofFe—C

5、uunderdifferentmillingtimes．AndtheinfluenceofmechanicalalloyingonthesolidstatesinteringofFe-Cucompoundpowderswasalsostudiedbyresearchthemetallurgicalstructure，density,hardnessandbendstrengthofthesinterThetestresultsshowedthattheparticleandthegrainsizewererefined，thehomogeneitydegre

6、eofthecomponentswasimproved，aftertheFe—Cucompoundpowdersmilled．Andthelargequantityofdefectenergy,distortionenergyandsurfaceenergywereaccumulatedintheFe-Cupowders．Thedifferentialscanningcalorimetry(DSC)experimentfoundthataftermilled30hours，theheatreleaseofthepowdersat900℃，1809．20J／g

7、，wasabout27timesthanthatofwhichhadnotbeenmilled(65．62J／g)．Byanalyzingthesinter(sinteredat900℃)ofFe-Cucompoundpowders(milled30h)，itwasshownthatthemetallurgicalstructureofwasfine，thecomponentwasuniformandthebondstrengthwasstrong．Thedensity,hardnessandbendstrengthwereimprovedby9．7％．84

8、．6％and51．2％．respectively．T