【摘要】：電極是濕法冶金行業(yè)、電化學(xué)工業(yè)中非常關(guān)鍵的器件,在電解工業(yè)中起著至關(guān)重要的作用。開發(fā)成本低、活性強(qiáng),導(dǎo)電好、耐蝕強(qiáng)、無污染的新型電極材料得到較廣泛的關(guān)注和研究。Pb-Ag合金電極因成本低、電化學(xué)性能好、易加工、可回收等優(yōu)點(diǎn)是電化學(xué)領(lǐng)域最廣泛使用的電極材料,但該電極的傳統(tǒng)制備方法還存在難以克服的諸多問題。針對Pb-Ag合金存在強(qiáng)度低,內(nèi)阻大,能耗高等缺點(diǎn),本論文采用超聲波細(xì)晶技術(shù)對凝固過程中的Pb合金進(jìn)行處理,細(xì)均化合金的初始晶粒及組織;利用多能場(物理聲場,強(qiáng)塑性力場,溫度熱場)聯(lián)合作用進(jìn)一步細(xì)化合金晶粒均化組織,探討多能場對Pb合金組織結(jié)構(gòu)的影響規(guī)律及晶粒尺寸與性能之間的關(guān)聯(lián)。通過觀察合金金相,四探針法測量導(dǎo)電性能,電化學(xué)工作站測試電化學(xué)性能,再對電極進(jìn)行槽電壓測試,對其耐蝕性和節(jié)能性進(jìn)行探討,研究超聲工藝參數(shù)(熔體溫度、超聲頻率、超聲功率)、超聲+冷軋工藝參數(shù)(壓下率、退火溫度)對合金電極材料的微觀組織和性能的影響,結(jié)果表明:(1)觀察合金的顯微組織和性能測試分析表明,超聲工藝(超聲頻率、超聲功率、熔體溫度)中熔體溫度對材料晶粒大小和極化電位影響最大,超聲功率對電極電阻率影響最大。經(jīng)超聲波+冷軋?zhí)幚淼脑嚇?在同一退火溫度下,壓下率為40%時,晶粒明顯細(xì)化,呈細(xì)小均勻分布的等軸晶。但隨著壓下率的繼續(xù)增大,在物理聲場和強(qiáng)塑性力場的綜合作用下,再結(jié)晶過程在較短時間完成,隨著時間的延長,晶粒部分長大。退火處理可有效細(xì)化晶粒,隨著退火溫度的升高,再結(jié)晶晶粒尺寸小幅度增大;(2)通過對不同工藝參數(shù)制備的合金,結(jié)合組織和性能分析可知,顯微組織中晶粒尺寸適中,組織均勻致密,可以降低電阻率,提高電化學(xué)性能,極化電位降低,耐蝕性提高,達(dá)到節(jié)能降耗的目的。超聲波最佳工藝下制備的鉛合金陽極電阻率為2.2495×10-6Ω.m,極化電位2.2895V,槽電壓為3.2198V,自腐蝕電流1.255×10-4A/cm2。通過超聲波+冷軋進(jìn)一步細(xì)化均勻化晶粒電阻率可降至1.6934×10-6Ω! m,降低15.83%,導(dǎo)電性能提升;極化電位為2.2000V,負(fù)移89.5mV,降低4.1%,槽電壓降為3.1083V,降低3.46%,催化活性提升,能耗降低;自腐蝕電流為1.083×10-4A/cm2,降低13.7%,耐蝕性能明顯提升,陽極壽命延長。(3)研究超聲頻率、超聲功率和熔體溫度對Pb-0.5%Ag合金陽極材料組織和性能(導(dǎo)電性能、電化學(xué)性能、耐腐蝕性能)的影響,綜合性能分析最終優(yōu)化出超聲處理的最佳工藝參數(shù)為超聲頻率30kHz、超聲功率220W、熔體溫度370℃C;超聲波+冷軋法在超聲頻率30kHz、超聲功率220W、熔體溫度370℃下處理1min后,退火溫度120℃,退火時間30min,壓下率40%,可獲得多能場綜合作用下制備Pb-0.5%Ag合金陽極的最優(yōu)工藝。
[Abstract]:Electrode is a key device in hydrometallurgy industry and plays an important role in electrolysis industry. The new electrode materials with low cost, high activity, good conductivity, strong corrosion resistance and no pollution have been paid more attention and studied. The Pb-Ag alloy electrode is easy to process because of its low cost, good electrochemical performance and easy processing. Recoverability is the most widely used electrode material in the field of electrochemistry, but there are still many problems in the traditional preparation of the electrode. Aiming at the disadvantages of low strength, large internal resistance and high energy consumption in Pb-Ag alloy, the ultrasonic fine crystal technique is used to treat the Pb alloy during solidification, the initial grain and microstructure of the alloy are finely homogenized, and the multi-energy field (physical sound field, and so on) is used. The effect of the strong plastic force field and the temperature and thermal field on the grain homogenization of the Pb alloy was studied. The effect of the multi-energy field on the microstructure of the Pb alloy and the correlation between the grain size and the properties of the alloy were discussed. By observing the metallography of the alloy, measuring the electrical conductivity by four-probe method, testing the electrochemical performance by electrochemical workstation, and then measuring the voltage of the electrode, the corrosion resistance and energy saving of the electrode are discussed, and the ultrasonic process parameters (melt temperature, melt temperature) are studied. The effects of ultrasonic frequency, ultrasonic power) and ultrasonic cold rolling parameters (reduction rate, annealing temperature) on the microstructure and properties of the alloy electrode materials are discussed. The results show that: (1) the microstructure and properties of the alloy are measured and analyzed. In ultrasonic process (ultrasonic frequency, ultrasonic power, melt temperature), melt temperature has the greatest influence on grain size and polarization potential, and ultrasonic power has the greatest influence on electrode resistivity. At the same annealing temperature, the sample treated by ultrasonic cold rolling has fine grain size and uniform distribution of fine equiaxed grains when the reduction rate is 40%. However, with the increasing of the reduction rate, the recrystallization process is completed in a short time under the combined action of the physical sound field and the strong plastic force field, and the grain grows partly with the prolongation of the time. Annealing treatment can refine the grain effectively, and the recrystallization grain size increases slightly with the increase of annealing temperature. (2) by analyzing the microstructure and properties of the alloy prepared with different process parameters, it can be seen that the grain size in the microstructure is moderate. The uniform and dense microstructure can reduce the resistivity, improve the electrochemical performance, decrease the polarization potential and improve the corrosion resistance, thus achieving the purpose of saving energy and reducing consumption. The anode resistivity is 2.2495 脳 10 ~ (-6) 惟 路m, the polarization potential is 2.2895 V, the cell voltage is 3.2198 V, and the corrosion current is 1.255 脳 10 ~ (-4) A / m ~ (2). The resistivity of homogenized grain can be reduced to 1.6934 脳 10 ~ (-6) 惟 ~ (-1) by ultrasonic cold rolling, and the electrical conductivity can be improved by reducing 15.83 惟 路m, polarization potential is 2.2000V, negative shift is 89.5mV, decrease of 4.1%, cell voltage to 3.1083 V, reduction of 3.46%, catalytic activity is improved, energy consumption is reduced. When the corrosion current is 1.083 脳 10 ~ (-4) A / cm ~ (2), the corrosion resistance is improved and the anode life is prolonged. (3) the effects of ultrasonic frequency, ultrasonic power and melt temperature on the microstructure and properties (conductivity, electrochemical performance, corrosion resistance) of Pb-0.5%Ag alloy anode are studied. The optimum processing parameters of ultrasonic treatment were as follows: ultrasonic frequency 30kHz, ultrasonic power 220W, melt temperature 370C, ultrasonic cold rolling at 30kHz, ultrasonic power 220W, melt temperature 120 鈩，

本文編號：2269214