【摘要】：QBe2鈹青銅是一種時效強化型合金,具有較好的彈性、塑性、強度、無磁性等優(yōu)良性能,廣泛應用在很多行業(yè),被譽為“有色彈性材料之王”。根據(jù)課題要求,致力于獲得一種優(yōu)良性能的彈性元件,本文通過對該合金分別進行熱變形行為和熱處理后的性能及組織研究,分析和討論了QBe2鈹青銅的高溫塑性變形行為,及熱處理對QBe2鈹青銅的性能及微觀組織的影響。研究結果表明:流變應力隨著溫度的升高而降低,隨著應變速率的降低而降低。在溫度為600℃、640℃,應變速率為0.001 s~(-1)、0.01s~(-1)的條件下流變應力曲線總體呈現(xiàn)動態(tài)軟化型,在熱拉伸條件為600℃-0.001s~(-1)尤其明顯;而在680℃-0001~0.01s~(-1)條件下,呈現(xiàn)為穩(wěn)定流動型。在溫度為600~680℃、應變速率為0.001~0.01s~(-1)的條件下,對QBe2鈹青銅熱變形過程綜合分析,可知合金的熱變形激活能Q=204.92KJ/mol,Arrhenius型本構方程為:在時效處理過程中,隨著溫度的升高,QBe2鈹青銅的抗拉強度和伸長率均先達到一定峰值,然后下降;硬度值逐漸降低,但較熱處理前原始狀態(tài),合金的硬度均增強。隨著時效時間的延長,合金的抗拉強度與伸長率同樣是先增大然后呈現(xiàn)減小的趨勢。240℃/2h,空冷+400℃/4h,空冷的時效工藝下,硬態(tài)QBe2鈹青銅合金的綜合性能最佳,合金的抗拉強度為833MPa,彈性模量為132.4 GPa,伸長率為17.7%。分級時效后合金的綜合力學性能優(yōu)于常規(guī)時效,隨著時效溫度越高,時效時間越,長瘤狀γ相增多,β相細小均勻。常規(guī)時效中低溫長時間時效,高溫短時間時效有利于提高合金彈性,同時分級時效中退火孿晶的出現(xiàn),也有利于提高合金綜合力學性能。通過對彈性性能優(yōu)化的實驗研究,發(fā)現(xiàn)彈性性能最佳的時效工藝為:硬態(tài)/780℃/15min,水淬+240℃/2h,空冷+400℃/4h,空冷。在此工藝下簧片能夠保持25次彎曲90o后,具有良好彈性的性能。厚度為0.15mm,圓弧角度為110o的硬態(tài)QBe2鈹青銅簧片獲得的彎矩值最大,而厚度為0.3mm、圓弧角度為60o簧片獲得的彎矩值最小。
[Abstract]:QBe2 beryllium bronze is a kind of aging strengthened alloy with good properties such as elasticity, plasticity, strength and nonmagnetism. It is widely used in many industries and is called "king of colored elastic materials". According to the requirements of the project, we are committed to obtain a kind of elastic element with excellent properties. In this paper, the high temperature plastic deformation behavior of QBe2 beryllium bronze is analyzed and discussed by studying the hot deformation behavior and the properties and microstructure of the alloy after heat treatment, respectively. And the effect of heat treatment on the properties and microstructure of QBe2 beryllium bronze. The results show that the flow stress decreases with the increase of temperature and with the decrease of strain rate. When the temperature is 600 鈩，

本文編號：2335536