碳纤维编织物增韧补强WC-TiC层状陶瓷刀具的制备与摩擦磨损性能研究

发布时间：2018-01-25 01:04

  本文关键词： 碳纤维编织物 层状陶瓷刀具 热压烧结 力学性能 微观形貌 摩擦磨损性能　出处：《太原理工大学》2017年硕士论文　论文类型：学位论文

【摘要】：高速切削技术加工效率与加工精度较高,在机械加工领域中扮演着极为重要的角色。高速切削技术对切削刀具的性能要求较高。目前,常用于高速切削加工的刀具有硬质合金刀具、金属陶瓷刀具、金刚石刀具、陶瓷刀具等,其中陶瓷刀具以其优越的性能和较低的价格而受到广泛的关注。然而陶瓷刀具韧性较低这一缺点严重制约了其进一步推广与应用。本文针对其缺点设计制备了碳纤维编织物增韧补强WC-TiC层状复合陶瓷刀具材料。研究了TiC含量、烧结温度、保温时间对碳纤维编织物增韧补强WC-Ti C层状复合陶瓷刀具材料力学性能和微观组织的影响;分析了其增韧补强机理;研究了陶瓷刀具与难加工材料间的摩擦磨损性能。本课题提出了碳纤维编织物增韧WC-TiC层状复合陶瓷刀具材料的设计原则,并根据这一设计原则分别选择纳米WC和TiC作为基体相与添加相;确定了粘结剂的成分为Ni,并对其润湿性做了分析;对材料间化学相容性以及物理相容性进行了分析,证明了本课题选择的材料符合层状复合陶瓷刀具的设计原则。实验研究了TiC含量、烧结温度和保温时间对碳纤维编织物增韧补强WC-Ti C层状复合陶瓷刀具材料微观组织和力学性能的影响。当烧结温度为1500℃、烧结压力为20MPa、TiC含量为10wt.%时,保温30min的CWT11号陶瓷刀具的抗弯强度最高,达到905.30MPa,同样的烧结温度和TiC含量下,保温45min的陶瓷刀具CWT31的维氏硬度和断裂韧度最高,分别达到了20.21GPa和12.55MPa·m1/2。实验分析了烧结温度、TiC的质量分数和烧结过程中的保温时间对碳纤维编织物增韧补强WC-TiC层状陶瓷刀具微观组织的影响及刀具本身的增韧补强机理。结果表明,随着TiC含量、烧结温度和保温时间的升高,材料的晶粒尺寸与气孔率不断增大,从而影响了材料的力学性能。分析材料的微观组织可知,材料的主要增韧方式有裂纹的偏转、桥联、分叉以及纤维增韧、层状复合增韧等。刀具同时存在沿晶断裂与穿晶断裂两种断裂方式。最后,实验研究了刀具样品与316 L奥氏体不锈钢、GCr15轴承钢、TC4钛合金间的干摩擦磨损性能。通过对不同滑动速度与载荷下的材料间摩擦因数与磨损率的测试,研究了不同烧结温度、TiC含量、保温时间对刀具样品摩擦因数和磨损率的影响,同时得到了不同滑动速度与载荷对材料摩擦因数和磨损率的影响。
[Abstract]:High speed cutting technology plays a very important role in the field of machining because of its high efficiency and precision. High speed cutting technology requires high performance of cutting tools. The tools used in high speed cutting are carbide tools, cermet tools, diamond tools, ceramic tools and so on. Ceramic cutting tools have attracted wide attention because of their superior performance and low price. However, the low toughness of ceramic cutters has seriously restricted their further promotion and application. In this paper, carbon was designed and prepared in accordance with its shortcomings. The toughening and reinforcing WC-TiC laminated ceramic tool material with fiber braided material was studied. The content of TiC was studied. The effects of sintering temperature and holding time on the mechanical properties and microstructure of WC-Ti C laminated ceramic cutters reinforced by carbon fiber braids; The toughening and reinforcing mechanism is analyzed. The friction and wear properties of ceramic tools and refractory materials were studied. The design principle of WC-TiC laminated ceramic tool materials toughened by carbon fiber braided material was put forward in this paper. According to this design principle, nano-WC and TiC were chosen as matrix phase and additive phase respectively. The composition of the binder was determined as Ni.The wettability of the binder was analyzed. The chemical compatibility and physical compatibility of the materials were analyzed. It was proved that the materials selected in this paper accord with the design principle of laminated ceramic tools. The content of TiC was studied experimentally. Effects of sintering temperature and holding time on microstructure and mechanical properties of WC-Ti C laminated ceramic tool materials toughened and reinforced by carbon fiber braided, when sintering temperature is 1500 鈩，

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