本文選題：Mg-Gd鎂合金 + 等溫處理　； 參考：《哈爾濱工業(yè)大學》2017年碩士論文

【摘要】：鎂是在所有實用結(jié)構(gòu)材料中屬于比重相對較小的金屬,主要以鎂元素組成的鎂合金其性能極其優(yōu)異。目前,鎂合金有很多成形方法,壓鑄、擠壓成形和固態(tài)鍛造都有他們的局限性。因此,半固態(tài)金屬加工技術的出現(xiàn)解決他們的問題,該工藝具備了鑄鍛工藝的綜合優(yōu)點。本文就是通過對Mg-Gd鎂合金棒材進行半固態(tài)等溫處理和半固態(tài)等溫壓縮方法分別研究其組織演變規(guī)律和力學行為變化,采用模鍛成形的工藝方法進行L型件模鍛成形并了解L型件的微觀組織變化和力學性能。通過Mg-Gd鎂合金半固態(tài)等溫處理及模鍛成形研究,確定Mg-Gd鎂合金最優(yōu)的半固態(tài)坯制備參數(shù),確認采用模鍛成形工藝方法對材料的成形效果,確定一條工藝簡便、成本低、材料熱物理性能高的Mg-Gd鎂合金零件加工途徑,促進半固態(tài)模鍛技術在Mg-gd鎂合金成形技術上的應用。半固態(tài)等溫處理實驗,首先通過DSC測試該材料的半固態(tài)溫度區(qū)間,在固液相溫度區(qū)間內(nèi)選取不同溫度。然后在不同保溫時間下進行等溫處理,借助掃描電鏡和圖像分析軟件等檢測手段,來研究該材料半固態(tài)組織的演變規(guī)律。最終通過分析表明通過半固態(tài)等溫處理,可以獲得晶粒細小、球化程度好而且晶粒尺寸均勻的半固態(tài)組織。通過半固態(tài)等溫壓縮實驗研究該材料在半固態(tài)等溫壓縮下力學行為。研究發(fā)現(xiàn)Mg-Gd鎂合金在半固態(tài)下,它的變形抗力較低,變形過程中的協(xié)調(diào)能力好,而且在半固態(tài)下的Mg-Gd鎂合金具有變形溫度和應變速率的敏感性。最終,通過生產(chǎn)性的工藝實驗,采用模鍛成形工藝,并以L型件為具體制件,在壓力機上成功制造出了L型件。并測試力學性能和觀察其微觀組織,并進行了分析研究。
[Abstract]:Magnesium is a relatively small proportion of metal in all practical structural materials. Magnesium alloys, mainly composed of magnesium, have excellent properties. At present, magnesium alloys have many forming methods, die-casting, extrusion forming and solid forging, so their problems are solved by the appearance of semi solid gold processing technology. In this paper, the microstructure evolution and mechanical behavior change of Mg-Gd magnesium alloy bar are studied by semi solid isothermal treatment and semi solid isothermal compression method. The forging process of L type parts by forging process is used to understand the microstructure change and mechanical properties of L type parts. Through the study of semi solid isothermal treatment and die forging of Mg-Gd magnesium alloy, the optimum preparation parameters of semi-solid billet of Mg-Gd magnesium alloy are determined. It is confirmed that the forming process method of die forging is used to determine the processing way of Mg-Gd magnesium alloy parts with simple process, low cost and high thermal physical properties of materials, and the semi-solid die forging is promoted. The application of technology in the forming technology of Mg-gd magnesium alloy. Semi solid isothermal treatment experiment. First, the semi-solid temperature range of the material was tested by DSC, and different temperatures were selected in the temperature range of the solid liquid phase. Then the isothermal treatment was carried out at different heat preservation time, and the materials were studied by means of scanning electron microscope and image analysis software. The evolution law of semisolid tissue is finally analyzed. The results show that the semi solid structure with fine grain, good spheroidization and uniform grain size can be obtained through semi solid isothermal treatment. The mechanical behavior of the material under isothermal compression in semisolid solid state is studied by semi solid isothermal compression experiments. It is found that Mg-Gd magnesium alloy is in semi solid state. The deformation resistance is low, the coordination ability in the deformation process is good, and the Mg-Gd magnesium alloy under semi-solid state has the sensitivity of deformation temperature and strain rate. Finally, through the production process experiment, the forging process is adopted, and the L type parts are used as the concrete parts, the L type parts are successfully manufactured on the pressure machine. The mechanical properties and the mechanical properties are tested. The microstructures were observed and analyzed.
【學位授予單位】：哈爾濱工業(yè)大學
【學位級別】：碩士
【學位授予年份】：2017
【分類號】：TG319
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本文編號：1952667