本文選題：鎢合金 + 高溫拉伸�。� 參考：《西安建筑科技大學》2017年碩士論文

【摘要】：鎢合金由于其獨特的力學性能而被廣泛用于民用工業(yè)與軍工業(yè)方面。隨著現(xiàn)代技術(shù)的不斷發(fā)展,鎢合金逐步取代貧鈾合金成為穿甲彈彈芯的主材料。鑒于鎢合金優(yōu)異力學性能和在軍事領(lǐng)域的重要地位,研究者們對于鎢合金在不同試驗條件下的力學性能進行了更深一步地研究。然而在相關(guān)研究中,由于鎢金屬的稀有性以及試驗過程中的環(huán)境控制等問題,導致進行大量重復性試驗的可行性不高。針對這一問題,在有限的試驗基礎上,利用計算機輔助軟件與試驗相結(jié)合的研究方法是可行的,且研究前景十分廣闊。本文以鎢合金中的93WNiFe合金為主要研究對象,以高溫拉伸試驗為基礎,綜合運用有限元仿真軟件以及數(shù)字圖像處理技術(shù),分析研究了93WNiFe合金在高溫拉伸作用下的力學性能變化以及微觀金相組織變化的特性及規(guī)律,在研究金屬材料的宏微觀力學性能方面提出了一種有效的研究思路及方法。通過使用電液伺服試驗機與高溫加熱爐對鎢合金進行常溫及高溫拉伸試驗,使用金相顯微鏡與場掃描電鏡對金相組織進行觀測采集,分析溫度對于鎢合金力學性能的影響得出:(1)隨著溫度的升高鎢合金的強度逐漸降低,其中抗拉強度與斷裂強度的變化規(guī)律基本相同,屈服強度變化較為平緩;(2)伴隨著溫度的升高,鎢合金的塑性出現(xiàn)高-低轉(zhuǎn)化現(xiàn)象,在400℃時塑性達到最佳。利用Ansys/Ls-dyna與HyperMesh有限元分析軟件對鎢合金進行常溫及高溫熱力耦合仿真模擬,通過模擬結(jié)果與試驗結(jié)果對比分析得出:(1)模擬計算的強度與試驗強度基本吻合,證明了有限元仿真的可行性及正確性;(2)通過合理添加失效準則,模擬出拉伸斷裂時的狀態(tài)并對斷裂后的斷口進行分析,得出其斷面收縮率變化與真實試驗塑性變化規(guī)律一致,出現(xiàn)高-低轉(zhuǎn)換現(xiàn)象;(3)預測性分析900℃時的拉伸力學性能,模擬數(shù)據(jù)符合真實力學性能變化趨勢。通過使用數(shù)字圖像處理技術(shù)對鎢合金的金相組織進行分析,以Matlab圖像處理為主要手段,運用改進分水嶺變化分割及矩形擬合的方法,分析微觀金相組織中鎢顆粒的變形,并對金相組織進行定量分析,得出高溫拉伸作用下鎢合金宏觀塑性變化規(guī)律是由于其微觀尺度變化所引起的。以試驗為基礎,通過使用有限元軟件仿真與數(shù)字圖像處理技術(shù)不僅可以高效、準確地對鎢合金高溫拉伸力學性能進行分析,且具有一定的經(jīng)濟效益。
[Abstract]:Tungsten alloys are widely used in civil and military industries because of their unique mechanical properties. With the development of modern technology, tungsten alloy has gradually replaced depleted uranium alloy as the main material of armour-piercing projectile. In view of the excellent mechanical properties of tungsten alloys and their important position in the military field, researchers have studied the mechanical properties of tungsten alloys under different experimental conditions. However, due to the rarity of tungsten metal and the environmental control during the test, it is not feasible to carry out a large number of repetitive tests. In order to solve this problem, it is feasible to combine the computer aided software with the experiment on the basis of limited experiment, and the research prospect is very broad. In this paper, the 93WNiFe alloy in tungsten alloy is taken as the main research object, based on the high temperature tensile test, the finite element simulation software and digital image processing technology are used synthetically. The changes of mechanical properties and microstructure of 93WNiFe alloy under high temperature tension were analyzed and studied. An effective research method was put forward to study the macro and micro mechanical properties of metal materials. The tensile tests of tungsten alloy at room temperature and high temperature were carried out by using electro-hydraulic servo testing machine and high temperature heating furnace. Metallographic microscope and field scanning electron microscope were used to observe and collect the microstructure of tungsten alloy. By analyzing the effect of temperature on the mechanical properties of tungsten alloy, it is concluded that the strength of tungsten alloy decreases gradually with the increase of temperature, and the change of tensile strength and fracture strength is basically the same. With the increase of temperature, the plasticity of tungsten alloy appears high to low conversion phenomenon, and the plasticity reaches the best at 400 鈩，

本文編號：1806899