本文選題：固態(tài)復(fù)合　切入點(diǎn)：復(fù)合材料　出處：《沈陽理工大學(xué)》2011年碩士論文

【摘要】：制備復(fù)合材料時(shí),根據(jù)增強(qiáng)顆粒進(jìn)入基體時(shí)基體的狀態(tài),有液態(tài)復(fù)合或半固態(tài)復(fù)合之分。但這些復(fù)合工藝均存在著增強(qiáng)顆粒與基體間的潤濕性差、有害界面反應(yīng)和顆粒偏聚等問題,極大地影響著復(fù)合材料性能的進(jìn)一步提高和推廣應(yīng)用。為此,作為液態(tài)復(fù)合和半固態(tài)復(fù)合概念的自然延伸,本文提出了固態(tài)復(fù)合的概念,并研究了SiC顆粒增強(qiáng)鋁基復(fù)合材料的固態(tài)復(fù)合和壓鑄成型工藝。 增強(qiáng)顆粒預(yù)處理是制備顆粒增強(qiáng)復(fù)合材料的前提性工藝步驟之一。通過掃描電鏡觀察和能譜分析,發(fā)現(xiàn)本研究所用SiC顆粒表面吸附或粘附著亞微米級的SiC粉體和少量Fe、Mn、V、Ni等雜質(zhì),為此通過酸洗和浸泡沖洗,有效地去除了顆粒表面的這些有害物。另外,為避免在復(fù)合坯料熔化時(shí)SiC顆粒與鋁液發(fā)生有害界面反應(yīng),對清洗后的SiC顆粒進(jìn)行了高溫氧化處理。氧化增重試驗(yàn)結(jié)果表明:經(jīng)過1000℃6小時(shí)的氧化處理,在碳化硅顆粒表面形成氧化層,其厚度經(jīng)測算約為117nm。 為了研究固態(tài)復(fù)合時(shí)增強(qiáng)顆粒在金屬基體中的分布均勻性,把經(jīng)過清洗和高溫氧化處理的SiC顆粒與鋁粉用帶強(qiáng)制攪拌的混料機(jī)進(jìn)行混合,然后經(jīng)冷壓、熱壓得到復(fù)合坯料。為避免鋁顆粒的氧化,在混合過程中混料機(jī)中始終通入氬氣進(jìn)行保護(hù)。試驗(yàn)結(jié)果表明,混料時(shí)間1.5小時(shí)即可使SiC顆粒均勻分布于鋁粉之中。熱壓的目的是,利用鋁粉的高溫塑性降低制坯壓力;同時(shí)可促進(jìn)SiC顆粒與鋁粉顆粒的緊密結(jié)合。 將復(fù)合坯料加入“貧鋁”7090Al合金溶液中進(jìn)行熔化分散,同時(shí)加以電磁攪拌,至半固態(tài)時(shí)進(jìn)行壓鑄成型。試樣檢測結(jié)果表明,采用固態(tài)復(fù)合工藝,SiC顆粒在基體合金中分布均勻,且結(jié)合狀況良好,沒有發(fā)現(xiàn)有害界面反應(yīng)和顆粒偏聚的現(xiàn)象。試樣摩擦磨損實(shí)驗(yàn)表明,復(fù)合材料摩擦系數(shù)較小,摩擦副表面基本無劃痕,說明所制備的復(fù)合材料具有良好的摩擦性能。
[Abstract]:When the composites are prepared, there are liquid or semi-solid composites according to the matrix state when the reinforced particles enter the matrix.However, these composite processes have some problems such as poor wettability between reinforced particles and matrix, harmful interfacial reaction and particle segregation, which greatly affect the further improvement and application of the properties of composites.Therefore, as a natural extension of the concepts of liquid and semi-solid composites, the concept of solid state composite is proposed, and the solid state recombination and die casting process of SiC particle reinforced aluminum matrix composites are studied.Pretreatment of reinforced particles is one of the process steps for preparing particle reinforced composites.By scanning electron microscope observation and energy dispersive analysis, it was found that the surface of SiC particles was adsorbed or adhered to submicron SiC powder and a small amount of Fe _ 2O _ mn _ (V _ (+)) Ni. These harmful substances were effectively removed by acid pickling and soaking and washing.In addition, in order to avoid the harmful interfacial reaction between SiC particles and molten aluminum when the composite billet melted, the SiC particles after cleaning were oxidized at high temperature.The results of oxidation weight gain test show that after 6 hours of oxidation at 1000 鈩，

本文編號：1689359