本文關(guān)鍵詞： 鎂合金 熱加工圖 軋制 織構(gòu)　出處：《青海大學(xué)》2016年碩士論文　論文類型：學(xué)位論文

【摘要】：本文采用氣體保護(hù)攪拌熔煉工藝和金屬型鑄造法制備了Mg-5Sn-2.5Pb鎂合金,并對其高溫壓縮和熱軋變形行為進(jìn)行了研究。通過熱壓縮實(shí)驗(yàn),計(jì)算了本構(gòu)關(guān)系和建立了熱加工圖,對Mg-5Sn-2.5Pb鎂合金的軋制工藝進(jìn)行了優(yōu)化。通過軋制實(shí)驗(yàn),研究了軋制參數(shù)對Mg-5Sn-2.5Pb鎂合金軋制成型機(jī)理的影響。結(jié)果表明:Mg-5Sn-2.5Pb鎂合金的峰值應(yīng)力隨著變形溫度的升高而降低,隨著應(yīng)變速率的增大而增大,這是由于動(dòng)態(tài)回復(fù)和動(dòng)態(tài)再結(jié)晶的軟化作用和加工硬化作用的共同影響。經(jīng)過計(jì)算得到Mg-5Sn-2.5Pb鎂合金的表觀激活能并確定了適合材料的本構(gòu)方程,即雙曲線函數(shù)形式的本構(gòu)方程。在此基礎(chǔ)上,通過計(jì)算及線性擬合求出了材料的能量耗散系數(shù)和不穩(wěn)定參數(shù),疊加功率耗散圖和流變失穩(wěn)圖得到應(yīng)變?yōu)?.6時(shí)的Mg-5Sn-2.5Pb鎂合金的熱加工圖。利用熱加工圖確定了最佳的可加工區(qū)域:材料在變形溫度為375°C~450°C、應(yīng)變速率為0.01s-1~0.3s-1。對Mg-5Sn-2.5Pb鎂合金軋制變形后的宏觀形貌、機(jī)械性能和顯微組織進(jìn)行了觀察與分析,確定軋制溫度為450°C、軋制速度為20rad/min是Mg-5Sn-2.5Pb鎂合金的優(yōu)化軋制工藝。軋制后鎂合金中產(chǎn)生了基面(0002)晶面平行軋制方向的織構(gòu)。結(jié)果表明,軋制溫度和軋制速率并不能改變合金的織構(gòu)類型,卻會(huì)影響一定的織構(gòu)強(qiáng)度。
[Abstract]:In this paper, Mg-5Sn-2.5Pb magnesium alloy was prepared by gas shielded agitation melting and metal mold casting. The deformation behavior of high temperature compression and hot rolling was studied. The constitutive relation was calculated and the hot working diagram was established by hot compression experiment. The rolling process of Mg-5Sn-2.5Pb magnesium alloy was optimized. The effect of rolling parameters on the rolling forming mechanism of Mg-5Sn-2.5Pb magnesium alloy was studied. The results showed that the peak stress of the Mg-5Sn-2.5Pb magnesium alloy decreased with the increase of deformation temperature. With the increase of strain rate, the effect of dynamic recovery and dynamic recrystallization on softening and work hardening is considered. The apparent activation energy of Mg-5Sn-2.5Pb magnesium alloy is calculated and the constitutive equation suitable for the material is determined. On the basis of this, the energy dissipation coefficient and the unstable parameters of the material are obtained by calculation and linear fitting. The thermal processing diagram of Mg-5Sn-2.5Pb magnesium alloy with strain 0.6 was obtained by superposing power dissipation diagram and rheological instability diagram. The optimum machinable region was determined by using the hot working diagram: the deformation temperature was 375 擄C ~ (1) 450 擄C, the strain rate was 0.01s ~ (-1) / 0.3s ~ (-1). The Mg-5Sn-2.5Pb magnesium alloy was rolled at a strain rate of 0.01s ~ (-1) / 0.3s ~ (-1). The macroscopic morphologies after deformation, The mechanical properties and microstructure were observed and analyzed. It was determined that the rolling temperature was 450 擄C and the rolling speed was 20 rad-1 / min. The optimized rolling process of Mg-5Sn-2.5Pb magnesium alloy was obtained. After rolling, the texture of the base plane of the magnesium alloy was produced in parallel direction. The results show that the rolling temperature is 450 擄C and the rolling speed is 20 radr / min. Rolling temperature and rolling rate can not change the texture type of the alloy, but will affect the texture strength.
【學(xué)位授予單位】：青海大學(xué)
【學(xué)位級別】：碩士
【學(xué)位授予年份】：2016
【分類號】：TG339

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1 解品;Mg-Sn-Pb鎂合金軋制成型機(jī)理研究[D];青海大學(xué);2016年

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本文編號：1503787