發(fā)布時間：2018-05-26 18:33

  本文選題：APM + 膠粘復合　； 參考：《太原科技大學》2017年碩士論文

【摘要】：將多孔泡沫金屬芯材與致密外殼通過一定連接方式組合成復合結構,既具有泡沫芯材的輕質、耐沖擊、抗振阻尼等特點,亦具有致密外殼的高強度特點,從而使泡沫金屬在民生、國防、航空航天等領域具有廣闊的應用前景。目前泡沫鋁復合結構的制備方式眾多,但多數制備工藝過程復雜,模具成本較高,尤其對于一些大型復雜構件,現有復合工藝難以保證充型效果及芯材孔隙率的均勻性。本文基于傳統(tǒng)粉末冶金發(fā)泡法(Powder Compacted Foaming,簡稱PCF法)泡沫鋁制備工藝,提出一種新型復合工藝。即通過泡沫化過程制備出具有先進孔隙結(Advanced Pore Morphology,簡稱APM)的泡沫鋁硅合金填料小球,隨后利用環(huán)氧涂覆膠粘和環(huán)氧發(fā)泡膠粘兩種方法將小球填充到中空模具中,形成夾芯復合結構。通過實驗獲得復合結構制備工藝的基本參數,并對其發(fā)泡和粘結機理進行分析。對利用此法獲得的復合結構進行力學性能測試,并與中空模具的力學性能進行比較。具體結論如下:(1)小球制作過程:利用PCM法制備泡沫鋁小球。發(fā)泡溫度、加熱速度、發(fā)泡劑種類對試樣膨脹過程和孔結構參數有較大的影響。當加熱速度為2.6℃/s時小球發(fā)泡綜合效果最好;發(fā)泡時間接近最大膨脹點時間點時孔結構最為均勻,APM小球外形球形度也較高;以Zr H2為發(fā)泡劑的預制體在膨脹過程中的溫度平臺區(qū)長度、到達最大膨脹點的溫度均要高于以Ti H2為發(fā)泡劑的預制體。(2)粘接復合過程:采用環(huán)氧膠粘和環(huán)氧發(fā)泡兩種方法用APM小球填充薄壁鋼管。采用環(huán)氧膠粘工藝進行粘接充型時,小球仍保持原位填充狀態(tài),填充均勻性僅與初始填充率有關;而采用環(huán)氧發(fā)泡工藝進行粘接充型時,直徑為15mm的小球經環(huán)氧樹脂發(fā)泡之后的分散均勻性強于直徑為20mm的小球;而當APM小球初始填充率在80%和100%時,發(fā)泡后在管中的分散均勻性要強于初始填充率為50%與30%的管件。采用直徑為15mm APM小球,填充率為80%和100%兩種參數對異形件進行充填效果分析,發(fā)現采用直徑15mm APM小球、當APM填充率100%時效果最好;且APM填充法提高了異形件內部泡沫體孔的平均圓形度,增強了孔結構的均勻性和重現性。(3)力學性能研究:采用環(huán)氧膠粘和環(huán)氧發(fā)泡兩種方法制備兩組復合管件樣本,將APM小球、薄壁空管及復合管件分別進行準靜態(tài)壓縮,結果表明:APM小球變形過程中為首先靠近工作臺兩端部位孔穴最先變形坍塌,隨后向中心部位擴展,直至全部壓潰;APM單元小球的應力-載荷曲線與傳統(tǒng)泡沫鋁形狀大致相同,平臺區(qū)跨度較大。而薄壁鋼管主要表現為非對稱變形模式,環(huán)氧膠粘-APM填充管為混合模式,環(huán)氧發(fā)泡-APM填充管表現出較典型的六角變形模式,且后二者褶皺數目要多于薄壁空管。環(huán)氧膠粘-APM復合管與環(huán)氧發(fā)泡-APM復合管提高了壓縮載荷水平,環(huán)氧發(fā)泡-APM復合管的理想吸能效率約為薄壁空管的188%,可達環(huán)氧膠粘-APM復合管的113%。
[Abstract]:The porous foam metal core and the dense shell are combined to form a composite structure by a certain connection, which has the characteristics of light weight, shock resistance, vibration resistance and damping of the foam core, and also has the characteristics of high strength of the dense shell. Thus, foam metal has a broad application prospect in the fields of people's livelihood, national defense, aerospace and so on. At present, there are many preparation methods of aluminum foam composite structure, but most of the preparation process is complex and the die cost is high. Especially for some large and complex components, the existing composite process is difficult to ensure the filling effect and the uniformity of core porosity. Based on the traditional powder metallurgical foaming method powder Compacted foaming (PCF) foam aluminum preparation process, a new composite process is proposed in this paper. That is to say, the foamed Al-Si alloy filler pellets with advanced pore junctions, Advanced Pore Morphology (APM) were prepared through the foaming process, and then the spheres were filled into the hollow mold by using epoxy coating adhesive and epoxy foaming adhesive. A sandwich core composite structure is formed. The basic parameters of the preparation process of composite structure were obtained by experiments, and the foaming and bonding mechanism were analyzed. The mechanical properties of the composite structure obtained by this method were tested and compared with the mechanical properties of the hollow die. The main conclusions are as follows: PCM method is used to prepare foamed aluminum pellets. Foaming temperature, heating speed and type of foaming agent have great influence on the expansion process and pore structure parameters. When the heating speed is 2.6 鈩，

本文編號：1938433