【摘要】：TC18合金具有密度低、比強(qiáng)度高等優(yōu)點(diǎn),已經(jīng)用于飛機(jī)起落架制造,但是面臨腐蝕和磨損問題。本文設(shè)計(jì)兩種防腐耐磨涂層,包括Al2O3涂層和WC-Co涂層,提高TC18合金的防腐耐磨性能。首先需要對(duì)基體進(jìn)行合適的表面預(yù)處理,然后通過正交試驗(yàn)法優(yōu)化涂層成分,同時(shí)采用DSC、IR優(yōu)化涂層固化工藝,制備防腐耐磨性能兼?zhèn)涞耐繉印１碚魍繉右恍┪锢頇C(jī)械性能,包括硬度、附著力、耐沖擊、剪切應(yīng)力等,涂層的耐磨性能及其耐腐蝕性能。研究結(jié)果表明:經(jīng)過除油、酸洗及化學(xué)氧化預(yù)處理,涂層金屬體系的附著力得到提升,且表面氧化薄膜提高基體的耐蝕性能。正交試驗(yàn)法優(yōu)化Al2O3涂層的成分(質(zhì)量百分比)是:800目Al2O3粉:1500目Al2O3粉:偶聯(lián)劑=24%:22%:2%,余下為環(huán)氧樹脂和固化劑(比例為1:1.05);WC-Co涂層的各成分(質(zhì)量百分比)是:WC-Co粉:800目Al2O3粉:偶聯(lián)劑=29%:6%:2%,余下為環(huán)氧樹脂和固化劑(比例為1:1.05)。在固化工藝參數(shù)為100℃下保溫2h條件下,得到涂層顏色均勻、表面完整,硬度、附著力、耐沖擊韌性滿足使用要求。對(duì)TC18合金基體和涂層的耐蝕性能進(jìn)行研究,電化學(xué)測(cè)試結(jié)果表明,涂層的自腐蝕電位高于基體,自腐蝕電流小于基體,Al2O3涂層對(duì)基體的保護(hù)效率達(dá)到98.8%,高于WC-Co涂層的98.3%,涂層可以起到很好的保護(hù)效果。隨著浸泡時(shí)間延長(zhǎng),涂層的容抗弧幅值不斷減小,在25天之后,減小幅度開始降低。對(duì)涂層分別進(jìn)行750h中性鹽霧試驗(yàn)和耐濕熱試驗(yàn),結(jié)束后涂層表面仍然保持完整,沒有起皮、剝離等現(xiàn)象,而基體鹽霧試驗(yàn)后表面出現(xiàn)腐蝕坑,涂層濕熱試驗(yàn)出現(xiàn)局部缺膠現(xiàn)象。在室溫干摩擦磨損條件下,與基體相比,涂層的摩擦系數(shù)都比較平穩(wěn),磨損量和磨損率小于基體,磨痕的寬度和深度也小于基體,表明涂層可以提供很好的耐磨防護(hù)。對(duì)于Al2O3涂層和WC-Co涂層的摩擦性能進(jìn)行比較,Al2O3涂層優(yōu)于WC-Co涂層。綜合耐腐蝕和耐磨損性能,Al2O3涂層的防護(hù)效果優(yōu)于WC-Co涂層。
[Abstract]:TC18 alloy has been used in aircraft landing gear manufacturing because of its low density and high specific strength, but it is faced with corrosion and wear problems. In this paper, two kinds of anticorrosive and wear resistant coatings, including Al2O3 coating and WC-Co coating, are designed to improve the anticorrosion and wear resistance of TC18 alloy. At first, it is necessary to pretreat the substrate properly, then optimize the coating composition by orthogonal test method, and adopt DSC,IR to optimize the coating curing process to prepare the coating with both anticorrosive and wear-resistant properties. Some physical and mechanical properties, including hardness, adhesion, impact resistance, shear stress, wear resistance and corrosion resistance of the coating were characterized. The results showed that the adhesion of the coated metal system was improved after deoiling, acid cleaning and chemical oxidation pretreatment, and the corrosion resistance of the substrate was improved by the surface oxidation film. The composition (mass percentage) of Al2O3 coating was optimized by orthogonal test as follows: 800-mesh Al2O3 powder: 1500 mesh Al2O3 powder: coupling agent = 24: 22: 2, the rest was epoxy resin and curing agent (1: 1.05); The composition (mass percentage) of WC-Co coating is as follows: WC-Co powder: 800 mesh Al2O3 powder: coupling agent = 29. 6: 2. The rest is epoxy resin and curing agent (1: 1.05). When the curing process parameters are 100 鈩，

本文編號(hào)：2427790