摘要
材料磨损现象主要发生在表面区域,对表面进行局域强化能够更加有效地提升材料的耐磨性能。陶瓷颗粒通常作为增强相会设计并制备成前驱体,并通过铸渗法制备金属基复合材料,进而达到局域强化的目的。前期研究结果证实了通过向前驱体中引入自放热粉体能够改善复合材料铸造质量。本文从前驱体黏合剂种类、用量、自放热粉体用量入手,对铸渗自放热陶瓷颗粒前驱体的制备工艺进行研究。结果表明,有机黏合剂PVAL和无机黏合剂水玻璃均不会影响放热反应的发生,但无机黏结剂水玻璃更适合于铸渗法;质量分数少于5%粉体用量时会导致部分颗粒表面明显无粉体包裹,而超过20%粉体用量时会导致包裹层内混合不均,在自放热时反应剧烈并出现较多孔洞;采用Al-ZnO 10%(质量分数)活性粉体,黏合剂为1 g∶1 mL的水玻璃制备前驱体性能最佳。
Wear phenomenon primarily occurs on the surface of materials,making the localized strengthening of the surface crucial for improving wear resistance.Typically,ceramic particles are employed as reinforcing agents to design and create precursors.Metal matrix composites are then formed through the casting infiltration method,achieving the desired localized strengthening.Previous studies have demonstrated that the introduction of self-exothermic powders into precursors enhances the casting quality of composites.This paper investigates the preparation process of a cast and infiltrated self-exothermic ceramic particle precursor,considering factors such as the type and amount of precursor binder,as well as the dosage of self-exothermic powder.The results indicate that the occurrence of the exothermic reaction is unaffected by the organic binder PVAL and the inorganic binder sodium silicate.However,the inorganic binder water glass is more suitable for the cast infiltration method.The inclusion of 5%(mass fraction)powder leads to noticeable absence of powder coverage on some particle surfaces,while a 20%dosage results in uneven mixing in the reaction layer,causing violent exothermic reactions and the formation of more voids.The best-performing precursor is prepared using 10%(mass fraction)Al-ZnO active powder and 1 g∶1 mL sodium silicate as a binder.
作者
于文臻
王怡然
高义民
施庆峰
高尚君
YU Wenzhen;WANG Yiran;GAO Yimin;SHI Qingfeng;GAO Shangjun(State Key Laboratory for Mechanical Behavior of Materials,School of Materials Science and Engineering,Xi'an Jiaotong University,Xi'an 710049,China;China Railway Baoji Bridge Group Co.,Ltd.,Baoji 721006,China)
出处
《铸造技术》
CAS
2023年第10期899-908,共10页
Foundry Technology
基金
国家重点研发计划(2021YFB3701204)
中国博士后科学基金面上项目(2021M692516)。
关键词
金属基复合材料
自放热活性粉体
铸造前驱体
metal matrix composites
self-exothermally active powders
casting precursor
