基于单磨粒的中密度纤维板磨削特性比较研究  

Comparative study on grinding characteristics of medium density fiberboard based on single grit

作　　者：张健 罗斌[1] 刘红光[1] 李黎[1] Zhang Jian;Luo Bin;Liu Hongguang;Li Li(School of Materials Science and Technology,Beijing Forestry University,Beijing 100083,China)

机构地区：[1]北京林业大学材料科学与技术学院,北京100083

出　　处：《北京林业大学学报》2021年第8期98-106,共9页Journal of Beijing Forestry University

基　　金：“十三五”国家重点研发计划(2018YFD0600304)。

摘　　要：【目的】探究圆锥形磨粒和棱锥形磨粒对中密度纤维板(MDF)的磨削特性差异,考察切削刃对于纤维材料磨削去除的作用机制,为实现MDF高效磨削提供理论依据。【方法】采用球头圆锥磨粒和五棱锥磨粒,采用楔形式划擦法,分别对MDF开展磨削试验。使用高速摄像机、三维测力仪、3D轮廓仪测定动态磨削过程、动态磨削力变化以及磨削表面的形貌轮廓等评价指标。【结果】球头圆锥磨粒在沟壑两侧形成更多的材料隆起,但沟壑边沿区域的初始表面完整性更好。当沟壑体积相近时,五棱锥磨粒产生更多的磨屑,且在单道磨削痕迹中产生磨屑的相对时点更早,更明显的磨屑流沿着切削方向从两个前刀面流出。五棱锥磨粒的切向磨削力达到最大值的相对时间点要早于球头圆锥磨粒。两种磨粒磨削MDF时的磨削力与磨削深度均呈现二次幂增加趋势,但五棱锥磨粒对应的磨削力比更大。两种磨粒切削时比磨削能与沟壑体积呈先降低后增大的二次幂关系,并存在一个转折点即临界沟壑体积(对应一个临界磨削深度);在沟壑体积基本相同时,球头圆锥磨粒真实的比磨削能较五棱锥磨粒更大。【结论】具有明显切削刃特征的五棱锥磨粒在磨削MDF时具有更优的磨削性能,具体表现为更高的材料去除率以及更高的能量利用率。可见,切削刃对于由纤维组成的材料具有重要的磨削去除作用。[Objective]The objective of this research was to investigate the difference of medium density fiberboard(MDF)cutting characteristics between spherical cone grit and pentagonal pyramid grit and study the action mechanism of cutting edges on fibrous material removal in sanding process.This research is going to provide some theory basis to fulfill highly efficient sanding.[Method]Spherical cone grit and pentagonal pyramid grit were used to conduct the cutting experiments through a wedge-style scratching method.High-speed camera,three-dimensional dynamometer and 3D profiler were applied to record and measure the dynamic cutting process,the cutting force variation and the sanded surface morphological profile.[Result]Spherical cone grit caused more material pile-up on both sides of the groove,where the initial surface integrity was better.For nearly the same groove volume,more chips formed in the pentagonal pyramid grit cutting,where the relative moment of chip formation was earlier for a single scratch with more evident chip flowing from the two rake faces.For a single scratch,the pentagonal pyramid grit presented less time to reach the peak value of tangential cutting force.The two kinds of abrasive grits when cutting MDF showed a quadratic increasing trend between cutting force and cutting depth.And the force ratio of the pentagonal pyramid grit was greater.There was a quadratic variation that first decreased and then increased between the specific grinding energy and the groove volume for the two kinds of abrasive grits.And there existed a turning point that was the critical groove volume(a critical cutting depth).When the groove volume was basically the same,the actual specific energy of spherical cone grit was greater than that of the pentagonal pyramid grit.[Conclusion]The pentagonal pyramid grit which was with evident cutting edges presented better cutting performances,specifically higher material removal rate and energy utilization rate,which shows that cutting edge plays a key role in removing fibrous materia

关 键 词：中密度纤维板 磨削 单磨粒 材料去除 比磨削能 

分 类 号：TS652[轻工技术与工程]