本文關(guān)鍵詞： 壓射沖頭 鋁青銅 摩擦磨損 熱疲勞　出處：《山東大學(xué)》2016年碩士論文　論文類型：學(xué)位論文

【摘要】：本課題以高強(qiáng)耐磨鋁青銅為研究對象,對其組織和性能進(jìn)一步改善和提高,以替代鈹青銅成為新型壓射沖頭材料,從而解決當(dāng)前國產(chǎn)沖頭壽命較短,高性能沖頭材料依賴進(jìn)口的問題,提高壓鑄生產(chǎn)效率�；趯荷錄_頭的失效分析,對常見沖頭材料的組織性能進(jìn)行對比,選擇鋁青銅作為新型壓射沖頭材料,通過成分及熔煉工藝的優(yōu)化,結(jié)合細(xì)晶強(qiáng)化及熱處理,制備出高強(qiáng)耐磨沖頭材料,并測試其耐磨性及熱疲勞抗性。目標(biāo)組織為：細(xì)化的晶粒及組織,強(qiáng)韌基體中均勻分布硬質(zhì)耐磨相。方案設(shè)計為：通過控制Al含量,適當(dāng)提高組織中硬/軟相比例。Fe、Ni、Mn等元素形成κ相,并能增加β相的穩(wěn)定性。在減少Ni含量的同時,發(fā)揮Mn的固溶強(qiáng)化作用。運(yùn)用固溶時效結(jié)合細(xì)晶強(qiáng)化,提升合金強(qiáng)硬度的同時兼顧材料的塑韌性,力求達(dá)到性能要求。經(jīng)過試驗,優(yōu)化合金成分為Al 10～10.5%、Fe 4%、Nil%、Mn 1～2%。為提高合金力學(xué)性能,確定最佳熱處理工藝為：900℃保溫2h后水淬+375℃保溫2h后空冷。合金細(xì)化劑選用Al-5Ti-B,最佳加入量為0.6%。經(jīng)優(yōu)化后合金的最終顯微組織為：β’相+少量α和γ2相構(gòu)成強(qiáng)韌基體,硬質(zhì)κ相細(xì)小彌散分布于基體之中。合金力學(xué)性能為：Rm:814MPa、Rp0.2:651MPa、A:8%、HB:336。試驗對比分析了鈹青銅、球鐵、鋁青銅的摩擦磨損和熱疲勞性能。實(shí)驗條件下,磨損結(jié)果顯示零件處于邊界摩擦和干摩擦的混合狀態(tài),材料耐磨性排序為：球墨鑄鐵試驗鋁青銅鈹青銅。熱疲勞試驗結(jié)果顯示,材料熱疲勞抗性排序為：鈹青銅試驗鋁青銅球墨鑄鐵。因此鋁青銅可作為壓射沖頭材料。此外,本文通過加快冷速,增強(qiáng)微觀偏析的方式,使原p枝晶形貌顯現(xiàn)。并對合金中的相進(jìn)行分析,發(fā)現(xiàn)鑄態(tài)組織中片狀或塊狀的a相,是三維空間中針片狀α相的二維顯現(xiàn)。組織中的κI顆粒形成于液相而非形成于凝固結(jié)束后,而κⅡ顆粒的析出有助于α相的細(xì)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，

本文編號：1548895