单层PCBN砂轮感应钎焊制备技术与磨损特性研究

发布时间：2018-04-13 16:45

本文选题：多晶立方氮化硼 + 高频感应钎焊　；参考：《南京航空航天大学》2017年硕士论文

【摘要】：多晶立方氮化硼(Polycrystalline cubic boron nitride,简称PCBN)磨粒是以微晶立方氮化硼(CBN)颗粒为原料,加入氮化铝(AlN)粘结剂,在高温高压下烧结而成的聚晶磨粒材料。多晶立方氮化硼磨粒保持了单晶CBN磨粒的优异耐磨性能,并且可以通过微破碎自锐效应使磨粒在磨削过程中始终具有锋利的微切削刃,以此克服普通单晶磨粒磨钝后砂轮锋利度难以保持的现象。高频感应钎焊技术加热效率高,砂轮基体变形小,是实现超硬磨料与砂轮基体高强度结合的有效渠道,特别是在制作大尺寸、高精度钎焊超硬磨粒砂轮方面具有广阔应用前景。有鉴于此,本文提出选用PCBN磨粒制作单层感应钎焊砂轮,探索砂轮制备机理,评价砂轮的磨削性能,研究砂轮的磨损特性。研究成果对于多晶CBN砂轮的研制及其在难加工材料磨削加工中的应用具有重要意义。本文完成的研究工作与取得的成果主要包括:(1)在不同感应钎焊参数下实现了Ag-Cu-Ti粉末、PCBN磨粒与45钢的钎焊连接,分析了PCBN磨粒钎焊界面微结构、表面生成物形貌及物相,对比了焊后磨粒的强度,优选了钎焊参数范围:感应电流为20-24A、扫描速度为0.5-1mm/s。(2)制作了单层感应钎焊PCBN砂轮,进行了高温合金GH4169的磨削试验,对比研究了不同磨削用量下磨削力、磨削温度、磨削功率及比能的变化规律。研究发现,单层PCBN砂轮具有优异的磨削性能,并且磨削力等特征参量随磨削用量的变化呈现出一定规律变化。(3)进行了单层钎焊PCBN砂轮磨损试验,研究了砂轮的主要磨损形式及磨粒形貌、磨粒磨损高度以及磨削力等特征参量随磨削过程的演变规律,发现PCBN磨粒的自锐行为可使砂轮锋利度长时保持在稳定的水平。
[Abstract]:Polycrystalline cubic boron nitride cubic boron nitrides (PCBNs) are polycrystalline abrasive materials sintered under high temperature and high pressure by adding aluminum nitride (AlN) binder with cubic boron nitride (CBN) particles as raw materials.Polycrystalline cubic boron nitride abrasive particles maintain the excellent wear resistance of single crystal CBN abrasive particles, and the abrasive particles can always have sharp micro-cutting edge in grinding process by micro-crushing self-sharpening effect.In this way, the sharpness of grinding wheel is difficult to be maintained after bluntness of single crystal abrasive grinding.High frequency induction brazing technology has high heating efficiency and low deformation of grinding wheel matrix. It is an effective channel to realize the high strength combination of superhard abrasive and grinding wheel matrix, especially in making large size and high precision brazing super hard abrasive grinding wheel.In view of this, this paper proposes to use PCBN abrasive particles to make single-layer induction brazing grinding wheel, to explore the mechanism of grinding wheel preparation, to evaluate the grinding performance of grinding wheel, and to study the wear characteristics of grinding wheel.The research results are of great significance for the development of polycrystalline CBN grinding wheel and its application in the grinding of difficult-machined materials.The research work and the results obtained in this paper mainly include: (1) the brazing connection between Ag-Cu-Ti powder and 45 steel was realized under different parameters of induction brazing. The microstructure of PCBN abrasive soldering interface, the morphology and phase of the surface product were analyzed.The strength of abrasive particles after welding is compared, and the brazing parameter range is chosen as follows: induction current is 20-24A, scanning speed is 0.5-1mm / s 路s. 2) single layer induction brazing PCBN grinding wheel has been made. Grinding test of superalloy GH4169 has been carried out, and grinding force under different grinding contents has been comparatively studied.Variation of grinding temperature, grinding power and specific energy.It is found that the monolayer PCBN grinding wheel has excellent grinding performance, and the grinding force and other characteristic parameters show a certain regularity with the change of grinding content. The wear tests of single-layer brazed PCBN grinding wheel are carried out.The evolution law of grinding wheel's main wear form, abrasive particle morphology, abrasive wear height and grinding force with grinding process is studied. It is found that the self-sharpening behavior of PCBN abrasive particles can keep the grinding wheel at a stable level when the sharpness of grinding wheel is long.
【学位授予单位】：南京航空航天大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：TG743

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