發(fā)布時(shí)間：2018-05-27 20:54

  本文選題：簡(jiǎn)化預(yù)處理 + 化學(xué)沉積　； 參考：《合肥工業(yè)大學(xué)》2015年碩士論文

【摘要】：W-Cu復(fù)合材料因具有高的強(qiáng)度、良好的導(dǎo)電導(dǎo)熱性,低的熱膨脹系數(shù)、良好的高溫抗氧化性等諸多的優(yōu)良性能而被廣泛用作電接觸器、真空斷路器、熱沉材料等功能和結(jié)構(gòu)器件。現(xiàn)代電子信息工業(yè)和國(guó)防工業(yè)高尖端領(lǐng)域的快速發(fā)展對(duì)W-Cu復(fù)合材料提出了新的發(fā)展方向和要求。由于W、Cu之間較大的性能差異,一直以來(lái)W-Cu復(fù)合材料的制備工藝都是該領(lǐng)域的研究熱點(diǎn)。制備超細(xì)/納米W-Cu復(fù)合粉末是獲得高性能W-Cu復(fù)合材料的方法之一,值得探索�；瘜W(xué)沉積是在水溶液中可控的自催化氧化還原反應(yīng),不需要提供電流,對(duì)基體沒(méi)有形狀和類型的限制,采用這種方法可以制備相分散均勻、純度高的復(fù)合粉體。本文采用簡(jiǎn)化預(yù)處理的化學(xué)沉積與粉末冶金相結(jié)合的方法制備了W-30Cu/(0,0.25,0.5,1,2) wt.% TiN復(fù)合材料,并對(duì)其工藝,優(yōu)化設(shè)計(jì)及性能等方面進(jìn)行研究,探索制備高性能的W-Cu復(fù)合材料的新途徑。主要研究結(jié)果如下：(1)通過(guò)對(duì)簡(jiǎn)化預(yù)處理工藝參數(shù)HF濃度的調(diào)整,制備具有表面缺陷的W粉,采用超聲波輔助化學(xué)沉積制備W-30Cu復(fù)合粉末。經(jīng)過(guò)簡(jiǎn)化預(yù)處理的W粉表面形成缺陷,有利于后續(xù)化學(xué)沉積過(guò)程中Cu顆粒的吸附、形核、長(zhǎng)大,且在其他條件相同的情況下,一定范圍內(nèi)隨著HF濃度的增加,簡(jiǎn)化預(yù)處理后的W粉表面胞狀凸起物數(shù)量增多,化學(xué)沉積后所得的W-Cu復(fù)合粉末沉積層越均勻：但是當(dāng)HF濃度繼續(xù)增大至一定值后,簡(jiǎn)化預(yù)處理后W粉表面所形成的缺陷數(shù)量減少,化學(xué)沉積過(guò)程中所吸附的Cu顆粒減少,最后所得的W-Cu復(fù)合粉末沉積層均勻度減少。當(dāng)HF溶度為60mL、L時(shí),復(fù)合粉末在400MPa壓制,1200℃燒結(jié)后燒結(jié)體試樣的相對(duì)密度高達(dá)95.04%,導(dǎo)電率高達(dá)53.24% IACS,高于國(guó)標(biāo)26.77%。(2)采用最優(yōu)簡(jiǎn)化預(yù)處理工藝制備W-Cu復(fù)合粉末,發(fā)現(xiàn)當(dāng)壓制壓力為400MPa,燒結(jié)溫度為1200℃時(shí),制備的W-30Cu復(fù)合材料組織結(jié)構(gòu)均勻且綜合性能優(yōu)良(具有最高的相對(duì)密度為95.04%;導(dǎo)電率為53.24% IACS,高于國(guó)標(biāo)26.77%)(3)納米TN的添加顯著影響了W-30Cu復(fù)合材料的組織結(jié)構(gòu)及性能,當(dāng)TiN的添加量為0.25wt%時(shí),盡管W-30Cu復(fù)合材料的相對(duì)密度和導(dǎo)電性稍微下降了,但是具有較好的綜合性能。
[Abstract]:W-Cu composites are widely used as electrical contactors, vacuum circuit breakers, heat sink materials and other functional and structural devices because of their high strength, good thermal conductivity, low thermal expansion coefficient, good high temperature oxidation resistance and many other excellent properties. The rapid development of modern electronic information industry and national defense industry puts forward new directions and requirements for the development of W-Cu composites. The preparation process of W-Cu composites has been a hot topic in this field due to the large difference in properties between WCU and Cu. The preparation of ultrafine / nano W-Cu composite powder is one of the methods to obtain high performance W-Cu composites, which is worth exploring. Chemical deposition is a controllable autocatalytic redox reaction in aqueous solution, which does not need to provide current and has no restrictions on the shape and type of matrix. This method can be used to prepare composite powders with uniform phase dispersion and high purity. In this paper, W-30Cu / O / 0 / 0.25% TiN composites were prepared by combining chemical deposition with powder metallurgy with simplified pretreatment. The process, optimization design and properties of W-30Cu / O / 0.25% W-Cu composites were studied in order to explore a new way to prepare high performance W-Cu composites. The main results are as follows: (1) W powder with surface defects was prepared by adjusting the concentration of HF, a simplified pretreatment process parameter, and W-30Cu composite powder was prepared by ultrasonic assisted chemical deposition. The formation of defects on the surface of W powder after simplified pretreatment is beneficial to the adsorption, nucleation and growth of Cu particles in the subsequent chemical deposition process, and with the increase of HF concentration in a certain range under the same other conditions. After simplified pretreatment, the number of cellular protrusions on the surface of W powder increased, and the W-Cu composite powder deposited by chemical deposition became more uniform: however, when HF concentration continued to increase to a certain value, After simplified pretreatment, the number of defects formed on the surface of W powder was reduced, the Cu particles adsorbed in the chemical deposition process were decreased, and the uniformity of the resulting W-Cu composite powder deposit layer was reduced. When the solubility of HF is 60 mL / L, the relative density of the sintered sample sintered at 1200 鈩，

本文編號(hào)：1943710