新型压射冲头材料的研究

发布时间：2018-02-28 20:49

  本文关键词： 压射冲头 铝青铜 摩擦磨损 热疲劳　出处：《山东大学》2016年硕士论文　论文类型：学位论文

【摘要】：本课题以高强耐磨铝青铜为研究对象,对其组织和性能进一步改善和提高,以替代铍青铜成为新型压射冲头材料,从而解决当前国产冲头寿命较短,高性能冲头材料依赖进口的问题,提高压铸生产效率。基于对压射冲头的失效分析,对常见冲头材料的组织性能进行对比,选择铝青铜作为新型压射冲头材料,通过成分及熔炼工艺的优化,结合细晶强化及热处理,制备出高强耐磨冲头材料,并测试其耐磨性及热疲劳抗性。目标组织为：细化的晶粒及组织,强韧基体中均匀分布硬质耐磨相。方案设计为：通过控制Al含量,适当提高组织中硬/软相比例。Fe、Ni、Mn等元素形成κ相,并能增加β相的稳定性。在减少Ni含量的同时,发挥Mn的固溶强化作用。运用固溶时效结合细晶强化,提升合金强硬度的同时兼顾材料的塑韧性,力求达到性能要求。经过试验,优化合金成分为Al 10～10.5%、Fe 4%、Nil%、Mn 1～2%。为提高合金力学性能,确定最佳热处理工艺为：900℃保温2h后水淬+375℃保温2h后空冷。合金细化剂选用Al-5Ti-B,最佳加入量为0.6%。经优化后合金的最终显微组织为：β’相+少量α和γ2相构成强韧基体,硬质κ相细小弥散分布于基体之中。合金力学性能为：Rm:814MPa、Rp0.2:651MPa、A:8%、HB:336。试验对比分析了铍青铜、球铁、铝青铜的摩擦磨损和热疲劳性能。实验条件下,磨损结果显示零件处于边界摩擦和干摩擦的混合状态,材料耐磨性排序为：球墨铸铁试验铝青铜铍青铜。热疲劳试验结果显示,材料热疲劳抗性排序为：铍青铜试验铝青铜球墨铸铁。因此铝青铜可作为压射冲头材料。此外,本文通过加快冷速,增强微观偏析的方式,使原p枝晶形貌显现。并对合金中的相进行分析,发现铸态组织中片状或块状的a相,是三维空间中针片状α相的二维显现。组织中的κI颗粒形成于液相而非形成于凝固结束后,而κⅡ颗粒的析出有助于α相的细化。
[Abstract]:In this paper, the high-strength and wear-resistant aluminum bronze is taken as the research object, its structure and properties are further improved and improved to replace beryllium bronze as a new type of punching material, so as to solve the problem of the short life of domestic punching head at present. The high performance punching materials depend on import to improve the production efficiency of die casting. Based on the failure analysis of injection punch, the structure and properties of common punching materials are compared, and aluminum bronze is selected as a new type of punching material. Through the optimization of composition and melting process, combined with fine grain strengthening and heat treatment, the high-strength and wear-resistant punch material was prepared, and its wear resistance and thermal fatigue resistance were tested. By controlling Al content and increasing the ratio of hard to soft phase, Fe / Ni Ni mn can form 魏 phase, and increase the stability of 尾 phase. While reducing the content of Ni, the stability of 尾 phase can be increased. The application of solid solution aging combined with fine crystal strengthening to improve the hardness of the alloy while taking into account the plastic toughness of the material in order to achieve the performance requirements. In order to improve the mechanical properties of the alloy, The optimum heat treatment process was determined as follows: water quenching for 2 h at 900 鈩，

本文编号：1548895