摘要
利用真空熔烧工艺制备了WCP-NiCrBSi/耐热钢复合材料,棒状增强相WCP-NiCrBSi均匀分布于基体表层,实现了复合材料的'硬韧匹配'。利用SEM、EDS和显微硬度等手段,对复合材料增强相和界面的微观组织结构进行了表征。在环-盘式试验机上对复合材料的高温磨损性能进行了研究,并与基体材料进行对比。结果表明,增强相WCP分布均匀,NiCrBSi合金在凝固过程中生成了γ-Ni(Ni3Si)、Ni-B、Cr-B和多元共晶物相。复合材料的增强相与基体之间为良好冶金结合,没有裂纹、气孔等缺陷。由于界面元素的互扩散,在增强相一侧发生了等温凝固,生成了γ-Ni固溶体层;在基体一侧的扩散影响区内弥散析出了大量的Fe-Cr-B化合物。在室温至600℃温度范围内复合材料的耐磨性都优于基体材料,复合材料的耐磨性优势在室温下最大,并随着温度的升高而逐渐减小。室温下,由于WCP凸出于磨损表面阻止了金属材料之间的直接接触,复合材料的磨损机制为轻微粘着磨损。在300℃和600℃下,由于磨损表面氧化物膜的形成,WCP-NiCrBSi/耐热钢复合材料的磨损机制转变为轻微氧化磨损。
WCp - NiCrBSi/refractory steel composite was fabricated by vacuum fusion sintering. The composite was constructed with rod-like WCp -NiCrBSi array within refractory steel matrix. This composite material structure could realize well compromise between hardness and toughness. The mierostruetures of the composite interface and WCe- NiCrBSi reinforcement were characterized using SEM, EDS and microhardness. The elevated temperature wear behavior of the composite was evaluated on ring-on-disc wear tester and compared with the unreinforced refractory steel. The results show that a metallurgical binding free from cracks and pores is produced between the refractory steel matrix and the WCp - NiCrBSi reinforcement. ＂/- Ni solid solution layer adjacent to the WCp - NiCrBSi reinforcement is formed by isothermal solidification and a large number of fine Fe - Cr - B precipitates are generated in the diffusion affected zone adjacent to the matrix due to mutual diffusion of elements. WCp are evenly dispersed within the WCp -NiCrBSi reinforcement and ＂/-Ni（Nia Si）, Ni -B, Cr- B and multiple eutectic are formed during the solidification of NiCrBSi alloy. In the temperature range from room temperature to 600 ℃, the wear resistance of the WCp - NiCrBSi/refractory composite is better than that of the unreinforced refractory steel. The wear resistance advantage of the composite at room temperature is maximum, and gradually decreases as the temperature increases. At room temperature, the wear mechanism of the composite is mild adhesive wear regime due to WCp preventing metal to metal contact. WCe - NiCrBSi/refractory steel the composite exhibits mild oxidation wear at 300 ℃ and 600 ℃ owing to the oxide film formation on the worn surface.
出处
《复合材料学报》
EI
CAS
CSCD
北大核心
2013年第5期125-131,共7页
Acta Materiae Compositae Sinica
