【作者】 冯益华；

【导师】 邓建新；

【作者基本信息】 山东大学 ， 机械制造及其自动化， 2003， 博士

【摘要】 本文从喷砂嘴的使用要求出发,研究开发出新型B₄C基陶瓷喷砂嘴,深入研究了陶瓷喷砂嘴材料的组分设计、工艺设计、力学性能和微观结构。运用气固两相流动理论对喷砂过程进行了模拟和仿真。对陶瓷喷砂嘴进行了大量的冲蚀磨损试验,分析了陶瓷喷砂嘴冲蚀磨损的影响因素,建立了陶瓷喷砂嘴冲蚀磨损模型,探索了陶瓷喷砂嘴的冲蚀磨损机理。 以B₄C为基体,（W,Ti）C固溶体为增韧补强剂,借助于热压过程的B₄C和（W,Ti）C原位化学反应,首次成功制备出B₄C/（W,Ti）C陶瓷喷砂嘴。与B₄C陶瓷相比,B₄C/（W,Ti）C陶瓷喷砂嘴材料的抗弯强度从300MPa提高到693MPa,断裂韧性从2.5MPa.m^1/2提高到3.9MPa.m^1/2,烧结温度从2200℃降低到1850℃,减少了能耗,降低了制造成本。 B₄C/（W,Ti）C陶瓷喷砂嘴材料的相对密度、抗弯强度和断裂韧性随（W,Ti）C含量的增加而增大,而硬度随（W,Ti）C含量的增加而降低。B₄C陶瓷的断口表面存在许多气孔,晶粒大小为6～8μm左右,而B₄C/（W,Ti）C陶瓷材料的断口表面几乎没有气孔存在,晶粒尺寸小于2μm,各相分布均匀,晶粒显著细化。 系统研究了10种不同材料喷砂嘴的冲蚀磨损行为,得出抗冲蚀能力由强到弱的顺序依次是:B₄C陶瓷、B₄C/（W,Ti）C陶瓷、Al₂O₃/（W,Ti）C陶瓷、YG8和YT15硬质合金、75瓷、铸铁（HT15-33）、45#淬火钢、45#钢和聚氨脂塑料,其中B₄C/（W,Ti）C陶瓷喷砂嘴表现出了最佳的综合性能指标。更多还原

【Abstract】 Based on the requirements of sandblasting nozzles, B4C based advanced ceramic nozzles have been successfully developed. Researches were carried out on its composition and hot-pressing parameters, mechanical properties and microstructure. With the theory of gas-solid two-phase flow, computer simulation of sandblasting process was discussed. Under the experimental results, effect of the factors that influence the nozzle wear was investigated, the erosion wear model was established, and the wear mechanisms were studied.B₄C/（W,Ti）C ceramic composites with different content of solid-solution （W,Ti）C were produced by hot pressing. Chemical reaction took place for this ceramic system during hot pressing sintering, and resulted in a B4C/TiB₂A/W₂B₅ composite. The flexure strength and fracture toughness were increased from 300 MPa and 2.5 MPa.m^1/2 for monolithic B₄C to 693 MPa and 3.9 MPa.m^1/2for B₄C/（W,Ti）C composites respectively, while the sintering temperature was lowered from 2200℃ to 1850℃.The density, flexure strength and fracture toughness of B4C/（W,Ti）C ceramic composites continuously increased with increasing （W,Ti）C content, while the hardness decreased with increasing （W,Ti）C content. There are a lot of obvious pores located at the B₄C grain boundary, and the grain size is about 6-8 urn. While there are almost no pores observed in the composite and the grain size is less than 2 μm.Erosion wear behavior of the nozzles made from different materials has been studied. Results showed that the wear resistance of the nozzles from high to low is B₄C, B₄C/（W,Ti）C, Al₂O₃/（W,Ti）C, 75 ceramic, YG8, YT15,45# steel, 45# hardened steel, cast iron（HT 15-33） and polyurethane plastic in turn, and B₄C/（W,Ti）C ceramic nozzle has high ratio of capability to price among all of these nozzles.The effect of abrasive particle hardness（H_p）, the ratio of particle hardness to nozzle更多还原