Name: determining tribocorrosion rate and wear-corrosion synergy of bulk and thin film aluminum alloys
Uploaded: 2018-09-11T14:30:00.000+00:00
Duration: 7 min 12 s
Description: Watch this Scientific Journal Video about Determining Tribocorrosion Rate and Wear-Corrosion Synergy of Bulk and Thin Film Aluminum Alloys at JoVE.com

这项工作得到美国国家科学基金会赠款 DMR-1455108 和 CMMI-1663098 的支持。

警告: 使用前请查阅所有相关材料安全数据表 (MSDS)。议定书中使用的一些化学品是有毒的。在进行实验时, 请使用所有适当的安全做法, 包括使用工程控制 (油烟机) 和个人防护设备 (安全眼镜、手套、实验室大衣、全长长裤和闭合脚趾鞋)。CNC (计算机数控) 机必须由训练有素的人员操作。氢氟酸必须在一个通风罩内处理, 这是一个标志, 上面标明 "危险, 氢氟酸在这个地区使用" 或类似。
1. 样品准备
注: 在 tribocorrosion 试验之前, 适当的表面制备样品是确保所完成测试的可靠性和提高测试重复性的关键。在本协议中, 以商业铝3003合金 (Si: 0.1, Fe: 0.4, 铜: 0.08, 锰: 1.1 .%, 平衡 Al) 为例。
<ol><li>散装金属样品制备<ol>
<li>3003合金 (以下简称 al) 被切割为 1.5 x 2 厘米2赠券, 使用 CNC 机器。</li>
		<li>机械研磨试样表面的一侧使用砂纸增加砂砾数 (#180, 240, 400, 600 和 1200)。<ol>
<li>研磨样品使用 #180 砂纸三十年代沿一个任意方向。</li>
			<li>旋转样品90˚和研磨它使用 #240 砂纸, 直到从前一步的划痕线完全消除。使用光学显微镜来帮助检查。</li>
			<li>重复样品旋转过程, 移动到下一个研磨纸上。使用软刷子在步骤之间清洁样品表面在自来水, 以消除任何污染, 从上一步。</li>
		</ol>
</li>
		<li>研磨后, 用不同尺寸的高粘度氧化铝抛光悬浮液 (1 µm、0.3 µm 和0.05 µm) 在超细纤维布垫上抛光试样表面。对每个复合尺寸使用不同的布垫。<ol>
<li>在清洁布垫上倒入〜1盎司1µm 氧化铝悬浮液 (10-30% 氧化铝, 0.6-1% 二氧化硅玻璃, 70-90% 水)。在一个方向上抛光样品, 或绘制 "8" 形状 (避免绘制 "0" 形状), 直到从上一步删除划痕线。</li>
			<li>重复0.3 和0.05 µm 抛光悬浮 (10-30% 氧化铝, 0.6-1% 二氧化硅玻璃, 70-90% 水), 直到达到镜面完成。</li>
		</ol>
</li>
		<li>将抛光试样放在烧杯中, 用40毫升的去离子 (DI) 水, 将烧杯放在超声波清洗器中1-2 分钟, 以除去任何表面微粒。使用压缩气体完全干燥的表面。图 1a显示了一个未打磨的与抛光铝样的示例。</li>
		<li>切割5厘米长, 1-2 毫米直径的电线和剥离保护塑料盖 (长度1厘米) 两端暴露内部铜线的空气。</li>
		<li>用导电胶带或导电环氧树脂将导线的一端电连接到样品背面 (未磨光的一侧)。如果使用导电环氧树脂, 按照制造商的建议, 直到完全治愈。</li>
		<li>使用电化学停止漆油漆 1×1 cm2窗口的抛光面和完整的背面的样品。在后侧, 漆在暴露的铜线上。</li>
		<li>在实验前, 在通风良好的油烟机中完全干燥所绘样品至少24小时。图 1b展示了被绘的散装样品的例子, 被使用作为工作电极为腐蚀和 tribocorrosion 测试。</li>
	</ol>
</li>
	<li>薄膜样品制备 注: 使用非平衡处理技术, 如物理气相沉积和电沉积, 在平板基板上沉积的金属薄膜 (如玻璃、硅晶片和其他金属板) 可用于 tribocorrosion 测试后的适当制备。在此, 以硅基片沉积的磁控溅射铝锰薄膜样品为例, 说明了关键步骤。<ol>
<li>抛光硅晶片 (100 毫米直径), 1:50 氢氟酸水溶液2分钟, 以去除任何表面氧化层。</li>
		<li>用95% 乙醇清洁硅晶片。然后用压缩空气将其烘干, 并将其直接转移到磁控溅射机真空室中。</li>
		<li>在 5 mTorr 氩气 (99.99%)1下, 在 80 W 输入功率下操作溅射机。在溅射机中使用铝锰靶材, 在锰膜 (以下简称铝薄膜) 上生长2-3 µm 厚度 Al-20。</li>
		<li>自旋涂层一薄保护层的正光刻胶 (约10毫升的100毫升硅晶片) 在沉积侧的硅晶片和骰子它成几个 1.5 x 2 cm2优惠券。</li>
		<li>将样品中的丙酮浸泡1分钟, 完全去除保护层。用酒精冲洗, 最后用压缩空气晾干。</li>
		<li>按照步骤1.1.5 和1.1.8 进行电气连接, 并为 tribocorrosion 测试绘制样品表面。图 1c显示了一个绘制的薄膜样本示例。</li>
	</ol>
</li>
</ol>2. Tribocorrosion 测试
<ol><li>Tribocorrosion 机安装<ol>
<li>使用在通用机械测试仪 (城市轨道交通) 上安装的定制设计的腐蚀单元进行 tribocorrosion 测试, 如图 2a所示。使用 tribocorrosion 测试设置的示意图, 如图 2b所示。图 3显示了自定义设计的腐蚀单元安装在城市轨道交通的旋转阶段。受力传感分辨率分别为5-500 锰和 10-1000 N 的载荷范围为50µN 和50锰。</li>
		<li>对于电化学测量, 使用 2 x 10-17安培电流分辨率和 1014 Ω输入阻抗。</li>
	</ol></li>
	<li>Tribocorrosion 率测量原理<ol>
<li>测量 tribocorrosion 电阻根据 ASTM G119 标准2, 其中总材料损失 T = C0 + W0 + S (参见介绍为细节)。<ol>
<li>从极化测试中测量腐蚀速率 C0 。</li>
			<li>从 tribocorrosion 试验中测量阴极极化时的纯磨损率 W0 。应用一个球盘配置, 使用氧化铝球施加相互机械磨损的负载范围的锰到几个 N。</li>
			<li>对于薄膜样品, 选择适当的正常载荷。这就确保了塑性变形被限制在顶部表面, 使沉积试样厚度足够大, 足以类似真实的散装材料行为。这种估计可以使用赫兹接触理论12。</li>
			<li>测量 tribocorrosion 率 T 从 tribocorrosion 测试在泛消费。</li>
			<li>计算与上述测量和方程1的协同作用。</li>
		</ol>
</li>
	</ol></li>
	<li>极化 (PD) 试验中腐蚀速率 C0的测定<ol>
<li>准备工作电极 (如分析中的大块或薄膜金属试样)。用丙酮清洗金属表面, 然后用95% 乙醇。</li>
		<li>在每次腐蚀运行前都要清洗腐蚀细胞。用家用洗涤剂擦洗细胞, 用自来水彻底冲洗。重复此步骤3次。</li>
		<li>用脱电离水 (DI) 水冲洗腐蚀细胞3次, 以除去自来水中发现的潜在污染物。</li>
		<li>将100毫升的95% 乙醇倒入腐蚀细胞中, 旋转周围以接触所有内部表面。倒出乙醇, 重复这一步骤3次。</li>
		<li>将腐蚀细胞留在通风罩下30分钟, 使所有乙醇完全蒸发。</li>
		<li>采取清洁, 干燥腐蚀细胞和冲洗它的电解质, 将用于腐蚀运行。每冲洗一次, 用40毫升电解质填充腐蚀细胞, 重复此过程3次。对于本协议, 用 3.5 wt% (0.6 米)、pH ≈7氯化钠水溶液 (即模拟海水) 冲洗腐蚀细胞。</li>
		<li>冲洗后, 用40毫升电解质填充腐蚀细胞, 准备好反应。</li>
		<li>设置三电极配置。使用 Al 样品, 标准 Ag/AgCl, 和活化钛网作为工作, 参考和柜台电极分别。</li>
		<li>将工作电极集中在腐蚀单元的底部, 用超级胶水胶水底部。将暴露的铜线尖端置于预期的电解质表面高度之上。</li>
		<li>将参考电极置于工作电极上方1厘米处。</li>
		<li>在试验 (工作电极) 周围松散地弯曲计数器电极以缠绕试样。计数器和工作电极之间的距离为2-4 厘米。</li>
		<li>用恒电位仪连接电极。确保电极不接触。</li>
		<li>打开与 USB 控制恒电位仪接口的电化学软件包。打开恒电位仪。</li>
		<li>打开并使用 "测量" 视图查看腐蚀环境的潜在和当前读数。在没有坡道电位的泛型阶段, 在工作 (正电位) 和计数器 (负极) 电极之间的电流读数约为0到0.01 µA。</li>
		<li>让样品在腐蚀细胞环境中平衡和稳定。时间期限为这变化 (1 到 6 h) 并且取决于被测试的材料。使用 "测量" 视图监视潜在的电位, 以确定是否达到稳定条件 (即小于 50 mV 的潜在变化超过半个小时)。</li>
		<li>运行腐蚀测试。随着腐蚀电位的稳定 (E),在相对于参考电极的正方向上, 斜坡的应用电位。</li>
		<li>从 "过程" 选项卡中选择 "安装" 视图中的循环伏安恒电位仪过程. 为腐蚀运行启用以下参数取样: 时间、工作电极 (我们) 电位和腐蚀运行电流。</li>
		<li>选择用于自动执行当前范围的选项。将范围中的最高电流设置为 10 mA, 并且范围中的最低电流为我们的 10 nA。</li>
		<li>通过将 "循环回" 参数设置为 0.8 mV 以允许滞后循环完成, 确保最终的截止选择是通过电位控制的。</li>
		<li>将 "度量" 视图中的泛消费项记录到泛化参数文本框中。将起始电位设置为 100 mV, 低于记录的泛消费价值。将上顶点电位设置为 800 mv, 下顶点到 100 mv 下方的起始电位和停止电位为 100 mv 低于下顶点电位。将扫描速率设置为 0.167 mV (ASTM 标准)。</li>
		<li>按 "开始"。几个小时后, 腐蚀试验完成。</li>
		<li>查看软件中的结果。 注: 光学显微镜将在每次测试后执行。丢弃在停止漆下显示缝隙腐蚀迹象的样品。每个测试条件的结果应至少重复三次。图 4显示了 3.5 .% 氯化钠水溶液中≈7的 PD 试验后大块和薄膜铝的代表性结果。</li>
		<li>从 PD 试验中确定点蚀电位 (E坑), 作为腐蚀电流迅速增加的电位 (图 4)。</li>
		<li>获得阴极极化斜率 (βc) 的标称值, 将一条直线与极化曲线的部分相对应, 其相对于 50 mV 低于 Eoc的电位。</li>
		<li>获得阳极极化斜率 (βa) 的标称值, 同样使用起始于电位 > 50 mV 的曲线部分, 高于 eoc , 并在 e坑结束。</li>
		<li>将这两种趋势推断为 Eoc和适当的平均值, 以获得标称腐蚀电流密度 (i.) (图 4)。</li>
		<li>从腐蚀电流中计算腐蚀速率 C0使用法拉第的转换 (1 µA-2≈10.9 µm/y), 假设与 Al3 +的形成一致的腐蚀。法拉第的方程式是 r = M/nFP (i), 其中 R 是腐蚀率, 我是从 PD 测试测量的腐蚀电流, M 是金属的原子重量, P 是密度, n 是指示数的电荷数在溶解反应中交换的电子, 和 F 是法拉第常数等效于 96485 C/摩尔. M/n 等于重量。</li>
	</ol></li>
	<li>阴极保护试验中0的磨损率测量 注: 为了测量磨损率, 在试样浸入溶液中时, 用4毫米直径的氧化铝球作为计数器, 在样品表面上划痕, 如图 5所示。下面是阴极保护试验的程序。<ol>
<li>在第2.3 节中执行从2.3.1 到2.3.13 的步骤。</li>
		<li>将压探头向下移动到样品表面, 尽可能接近 (离样品表面1毫米的距离)。确保压停留在样品中心附近, 电极、探头和样品表面之间没有电接触。</li>
		<li>将压向前移动200毫米. 将 3.5 .% 氯化钠水溶液倒入腐蚀细胞, 直至所有电极、探针和试样表面浸入。</li>
		<li>将压探头向下移动到样品表面尽可能接近。将电极与恒电位仪连接。</li>
		<li>打开与 USB 控制恒电位仪接口的电化学软件包。打开恒电位仪。</li>
		<li>选择实验以查看直流腐蚀, 选择恒电位模式。</li>
		<li>应用 350 mV 以下的阴极电位。这种阴极电位 (350 mV 以下) 是为了避免在滑动过程中的氢演化反应, 这可能会导致样品的脆化13。最初的潜力和最终的潜力是-350 mV vs Eoc。实验总时间为1800秒, 包括300s 时间。</li>
		<li>通过应用1赫兹划痕频率、5 mm 划痕长度和 0.5 N 正常负载, 建立城市轨道交通软件的磨损试验。按下磨损系统中的 "运行" 按钮启动 tribocorrosion。注意, 划痕频率、划痕长度和应用载荷是测试参数, 可以根据实验的目的而变化。</li>
		<li>1800秒后, 测试完成。查看城市轨道交通软件的结果。为了可靠的测试, 在相同条件下重复测试至少三次。</li>
		<li>使用表面轮廓测量每个样品沿磨损轨迹的至少三个不同位置的磨损轨迹的深度。扫描方向垂直于划痕线, 扫描长度大于磨损轨道宽度 (见图 6)。轮廓触笔的半径为5µm, 手写笔力为3毫克, 扫描分辨率为0.028 µm/样例。</li>
		<li>导出配置文件测量数据。使用软件直接集成还没穿破表面下的深度 (图 7中的阴影区域)。</li>
		<li>计算横断面磨损面积<img alt="Equation 2" src="/files/ftp_upload/58235/58235eq2.jpg" style="opacity: 0.9;"> </img>, 如 h (x) 是位置 x 的函数的表面高度, a 为磨损履带宽度。使用 a, 计算磨损量为<img alt="Equation 3" src="/files/ftp_upload/58235/58235eq3.jpg" style="opacity: 0.9;"> </img>(A 是横断面磨损面积, L 是磨损履带长度 = 5 毫米)。</li>
		<li>最后, 计算0 w0= V/升的磨损率, 在那里我是总滑动距离。</li>
	</ol></li>
	<li>tribocorrosion 试验中 tribocorrosion 率 T 的测定<ol>
<li>以下步骤 2.4. 1-2. 4.8 除步骤2.4.6 外, 在测试期间将应用电位设定为泛型。</li>
		<li>测试完成后, 按照步骤2.4.10 计算 t = V/升.</li>
	</ol></li>
	<li>磨损腐蚀协同作用的计算<ol>
<li>在执行所有上述步骤后, 计算磨损-腐蚀协同作用为 S = t W0-C0, 其中 t 是总材料损失测量在泛型, W0是材料损失测量在阴极电位主要由于机械磨损 (与磨损相比, 腐蚀变得微不足道), 而 C0是由 PD 测试14、15所估计的纯腐蚀造成的物质损失。注意, 如果 C0是从 PD 测试中的深度损耗/年来衡量的, 重要的是要将其转换为等效的体积损耗, 以便正确计算 S。</li>
	</ol></li>
</ol>

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(7), 573-583 (2008).</li><li>Watson, S. W., Friederdorf, F. J., Madsen, B. W., Cramer, S. D. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Methods+of+measuring+wear-corrosion+synergism.">Methods of measuring wear-corrosion synergism.</a> Wear. 181, 476-484 (1995).</li><li>Assi, F., B&#246;hni, H. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Study+of+wear-corrosion+synergy+with+a+new+microelectrochemical+technique1.">Study of wear-corrosion synergy with a new microelectrochemical technique1.</a> Wear. (233-235), 505-514 (1999).</li><li>Mraied, H., Cai, W. 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作者声明没有竞争的财政利益。

在此协议中有几个关键步骤。首先, 在 tribocorrosion 试验之前对样品进行适当的表面制备, 对于确保测试的可靠性和提高测试重复性至关重要。不同的散装合金将按照不同的程序准备, 以确保受控表面粗糙度, 并清除任何表面污染物或鳞片。此处描述的过程仅包括机械研磨和抛光。这种方法一般适用于中、高硬度合金, 如铝、钛、镍、铜合金和钢。对于镁合金等软合金, 电化学抛光或离子铣削应与机械抛光配合, 达到预期的表面粗糙度。其次, 对于薄膜样品溅射, 在溅射腔中保持超低 (< 10-6乇) 真空是保证沉积膜中低缺陷浓度的关键, 否则会影响镀层的耐腐蚀性。显著。第三, 在将散装或薄膜样品准备成工作电极时, 必须确保样品与连接 (铜线) 之间有良好的电连接。本协议采用导电胶带或导电环氧树脂。另外, 还可以使用焊接、点焊或类似技术。然而, 在焊接过程中加热对试样的显微组织和最终 tribocorrosion 电阻的影响必须仔细评估。这对于低熔点的金属和合金尤其重要。最后, 由于 tribocorrosion 涉及三体的相互作用 (包括接触的两个物体和中间的第三个物体), 在执行重复 tribocorrosion 测试时, 确保使用新的球尖 (或球尖的新区域) 是很重要的。
目前的协议通过测量材料损失来评估 tribocorrosion 率。通过对该协议的修改, 可以很容易地对 tribocorrosion 的钝化和钝化动力学进行评价。这是通过跟踪电流, 电位和摩擦系数 (COF) 的变化在测试过程中实现的。举例来说,图 10和11显示了 tribocorrosion 试验后铝薄膜的腐蚀电位和 COF 的演化的代表性结果。图 10中的箭头表示划痕的开始和结束。可以看出, 对于无源合金, 如 Al, 在 tribocorrosion 过程中的机械破坏导致磨损轨道上的被动薄膜局部击穿/去除, 并暴露出一个 depassivated 区域, 导致腐蚀电位降低 20 mV。我们早期的工作16表明, 由于试验参数 (如应用载荷、滑动速度、温度) 相同, 腐蚀电位降低的幅度与金属的显微结构密切相关。对于硬度较高、显微组织较细的铝, 同样的应用载荷可能导致较小的 depassivated 面积, 从而减小腐蚀电位的变化。还指出, 在开路模式下, 电流太低, 无法检测到电路是 "打开" 的。然而, 在施加阴极或阳极电位的 tribocorrosion 试验中, 目前的演变可以被监测。在我们以前的工作16中可以找到一个例子。图 12显示了铝薄膜在 tribocorrosion 过程中的当前演化过程, 其阳极电位为 200 mV, 比泛型更积极。这种阳极电位是在被动区内选择的, 但远远低于点蚀电位。该结果可用于量化磨损加速腐蚀。在这种情况下, 总的材料损失可以评估为 T = v机械+ v化学, 其中 v机电和 v化学对应于机械和电化学材料损失的贡献, 分别。具体来说, V化学可以被认为是由金属氧化产生的阳极应用电位。因此, 它可以计算法拉第定律为17,18,19<img alt="Equation 4" src="/files/ftp_upload/58235/58235eq4.jpg" style="font-size: 14px;">, 其中 Q 是电荷 (计算通过乘以平均阳极电流在和之前的差异滑动的时间), M 是分子量, n 是氧化价, F 是法拉第常数, 而ρ是 al 的密度.图 13显示了两种铝薄膜术语的典型结果。从上述讨论中可以看出, 对电化学参数变化的评价, 除了减重外, 还将为 tribocorrosion 中的钝化动力学提供重要的洞察力。
这里提出的议定书也有若干限制。首先, 腐蚀细胞是由聚四氟乙烯 (聚四氟乙烯) 或类似材料制成的。因此, 所有的测试都是在室温附近进行的。对于需要更高温度的应用 (例如,核反应堆核心的400摄氏度以上), 必须制造一种特殊的腐蚀电池和尖端, 以经受高温蠕变和腐蚀。在高温下处理熔融盐电解质和金属样品也需要额外的安全。其次, 在工作电极附近的参考电极的附着 (试样) 限制了磨损运动为线性对等。在需要样品旋转运动的应用中, 必须设计一个特殊的 tribocorrosion 装置。第三, 在目前的设置, 磨损刮率比腐蚀率快得多。因此, 与所有其他条款相比, C0的贡献是微不足道的。虽然在有限的试验时间内, 腐蚀本身并没有导致重大的物质损失, 但其对 S 的影响是显著的。在现实世界中, 机械划痕在更低的频率下发生, 这种趋势可能会改变 C0可能成为主导地位的地方。最后, 必须特别注意在测试过程中产生的错误。这对于评价 tribocorrosion 率 (T)、磨损率 (W0) 和腐蚀率 (C0) 的磨损-腐蚀协同作用尤为重要。因而错误可以被积累。为了尽量减少在 T 和 W0中生成的错误, 非接触式3D 光学轮廓 (而不是接触2D 轮廓) 可以用来确定总的材料损耗量。为了减少 C0中的误差, PD 测试可以与非破坏性的 EIS (电化学阻抗谱) 测试结合, 以评估腐蚀率20。
作为最后的说明, tribocorrosion 速率不是物质属性, 而是一个系统的响应, 取决于测试参数 (应用负荷, 滑动速度等), 环境 (温度, pH 值, 盐浓度等), 和材料性能 (硬度、表面粗糙度等)。此处介绍的协议仅使用一组条件进行演示。在处理不同的系统时, 读者应考虑差异, 并在样本准备、测试设置和数据分析方面采取适当的改变。替代测试设置, 包括在板上的针脚 (往复), microabrasion, 缸在酒吧,等等, 可以在21找到。Tribocorrosion 是一个新兴的跨学科学科。希望这项议定书将有助于评估现有的工程材料以及设计抗磨损和腐蚀降解的新材料。这些材料在未来的应用中越来越被要求, 如先进的植入式医疗设备, 下一代核电厂, 以及高容量的快速充电电池等, 这些都不仅需要强大和强硬的材料, 但在与一些极端的环境进行交互时, 它是健壮可靠的。

Tribocorrosion 是一种材料降解过程, 由磨损和腐蚀的复合效应1,2。Tribocorrosion 发生在自然界和工业应用中, 机械接触和腐蚀性环境同时存在。tribocorrosion 的复杂性在于化学和机械降解机制不是相互独立的。由于协同作用, 机械和化学攻击的组合往往导致加速失败。因此, 总的材料损耗可以计算为 T = C0 + W0 + S (eqn 1), 其中 C0是材料损失造成的腐蚀在没有磨损, W0是由于机械磨损的材料损失在没有腐蚀, S 是由于磨损-腐蚀协同作用的物质损失3,4。与氧或水接触时, 铝、钛、不锈钢等无源合金的协同作用显著, 如铝合金、钛合金、和不锈钢等, 自发形成保护薄 (少量纳米厚度) 氧化物膜 (被动膜), 6。在腐蚀过程中, 如果这种被动薄膜在局部受到机械磨损的干扰, 钝化可能导致局部腐蚀和意外故障1、3、7、8, 9。
作为 tribocorrosion 在我们社会中的经济影响的一个例子, 磨损和腐蚀估计在美国每年花费近3000亿美元,10。在佛罗里达, 由于海洋经济 (捕鱼、海运和沿海建设), tribocorrosion 的结构合金在海水中的现象是有意义的, 它贡献了佛罗里达州11的国内生产总值的4% 左右。因此, 更好地理解金属和合金的 tribocorrosion, 将会在苛刻的环境服务条件下为合金的应用和使用提供更好的指导。这种理解还将有助于改进设计原则, 以制造新的合金和涂层对 tribocorrosion 和提高耐久性。
Tribocorrosion 研究需要摩擦和电化学测量系统的集成。摩擦提供受控机械载荷和相对运动, 并测量摩擦力和试样表面高度的变化。电化学测量系统包括具有零电阻电流表 (可选) 的恒电位仪/结合恒电流, 用于确定开路电位 (泛光) 和电化学极化测量。这种技术提供了一种快速、廉价的方法来获得材料的电化学性能, 在这种情况下, 通过观察电荷传递过程对受控电化学扰动的响应, 可以测量金属的腐蚀速率。.在这里, 我们提出了一个测试协议, 以确定的 tribocorrosion 率和磨损腐蚀协同的铝合金, 主要遵循 ASTM 标准 G1192。此协议包括样本准备、机器设置、tribocorrosion 测试和测试后计算过程。我们希望这一努力将有利于这些新的领域进行可靠和可重复的 tribocorrosion 测试, 以评估的变形和降解行为的散装和薄膜金属样品。

<table><tbody><tr><td>UMT (universal mechanical testing) machine</td><td>Bruker</td><td>UMT-2</td><td></td></tr><tr><td>Potentiostat</td><td>Gamry</td><td>Reference 600</td><td></td></tr><tr><td>Surface profilometer&amp;nbsp;</td><td>Veeco&amp;nbsp;</td><td>Dektak150</td><td></td></tr><tr><td>Al3003</td><td>Metal supermarkets</td><td>3003</td><td></td></tr><tr><td>Sodium choloride</td><td>Fisher Scientific</td><td>S640-3</td><td></td></tr><tr><td>DI water</td><td>USF NREC</td><td></td><td></td></tr><tr><td>Alcohol</td><td>Fisher Chemical</td><td>A405P-4</td><td></td></tr><tr><td>Grinding paper</td><td>LECO Corporation</td><td>810-221-300 (#180)&lt;br/&gt; 810-223-300 (#240)&lt;br/&gt; 810-227-300 (#400)&lt;br/&gt; 810-229-300 (#600)&lt;br/&gt; 810-036-100 (#1200)</td><td></td></tr><tr><td>Polishing Pad</td><td>Pace Technologies</td><td>NP. 7008</td><td></td></tr><tr><td>Polishing suspension</td><td>Pace Technologies</td><td>NANO2-1010-06 (1 um)&lt;br/&gt; NANO2-1003-06 (0.3 um)&lt;br/&gt; NANO2-1005-06 (0.05 um)</td><td></td></tr><tr><td>Stop-off lacquer</td><td>Romanoff</td><td>210-1250</td><td></td></tr><tr><td>Ag/AgCl Reference electrode</td><td>SYC Technologies, Inc.</td><td>CHI111</td><td></td></tr><tr><td>Compressed air</td><td>Office depot</td><td>911-245</td><td></td></tr><tr><td>Ultrasonic cleaner</td><td>Cole Parmer</td><td>8890</td><td></td></tr><tr><td>Sputtering coater</td><td>Torr International</td><td>CRC-100</td><td></td></tr></tbody></table>

determining tribocorrosion rate and wear-corrosion synergy of bulk and thin film aluminum alloys

诸如航空航天和海洋工业、核系统、微电子、电池和生物医学设备等领域的服务条件日益复杂和严重, 对可靠的性能提出了巨大的挑战.在机械和电化学攻击共存的极端条件下接触的合金。因此, 在这种极端条件下, 寻找合金以减轻磨损和腐蚀的联合攻击 (即tribocorrosion) 的方法对于提高其可靠性和使用寿命非常关键。挑战在于磨损和腐蚀不是相互独立的, 而是协同工作以加速总的材料损耗。因此, 需要一种可靠的方法来评估金属和合金的 tribocorrosion 电阻。本文给出了一种在室温下腐蚀环境下测定铝基散装和薄膜样品的 tribocorrosion 率和磨损腐蚀协同性的协议。

根据上面描述的测试协议, tribocorrosion 速率 (T) 以不同的电位进行测量。图 8代表了铝薄膜样品在阴极 (tribocorrosion 以下 350 mV)、开路和阳极 (200 mv 以上) 电位下获得的材料损失。试验在 3.5 .% 氯化钠水溶液中进行5分钟 0.5 N 正常负荷, 在1赫兹滑动频率和5毫米冲程长度。在每次测试之前, 该产品稳定了20分钟.图 9显示了 eqn 的所有组件的摘要, 包括 tribocorrosion 率 (T)、磨损率 (W0)、腐蚀速率 (C0) 和铝薄膜的磨损腐蚀协同作用。
<img alt="Figure 1" class="xfigimg" src="/files/ftp_upload/58235/58235fig1.jpg"> 图 1.(a) 未磨光和抛光的铝散装样品的照片 (b) 有线和彩绘散装, (c) tribocorrosion 测试用薄膜铝试样。<a href="https://www.jove.com/files/ftp_upload/58235/58235fig1large.jpg" target="_blank">请单击此处查看此图的较大版本.</a>
<img alt="Figure 2" class="xfigimg" src="/files/ftp_upload/58235/58235fig2.jpg"> 图 2.(一) 没有定制的 tribocorrosion 单元的布鲁克 optics 轨道交通机器前面的照片。(b) tribocorrosion 测试设置示意图。<a href="https://www.jove.com/files/ftp_upload/58235/58235fig2large.jpg" target="_blank">请单击此处查看此图的较大版本.</a>
<img alt="Figure 3" class="xfigimg" src="/files/ftp_upload/58235/58235fig3.jpg"> 图 3.自订制作的 tribocorrosion 单元照片安装在城市轨道交通转台式阶段。该电池是由聚四氟乙烯与 O 形环在底部表面, 以防止液体泄漏在 tribocorrosion 测试。<a href="https://www.jove.com/files/ftp_upload/58235/58235fig3large.jpg" target="_blank">请单击此处查看此图的较大版本.</a>
<img alt="Figure 4" class="xfigimg" src="/files/ftp_upload/58235/58235fig4.jpg"> 图 4.在0.6 米氯化钠溶液浸泡1小时后, 代表极化极化曲线的铝体积和薄膜。<a href="https://www.jove.com/files/ftp_upload/58235/58235fig4large.jpg" target="_blank">请单击此处查看此图的较大版本.</a>
<img alt="Figure 5" class="xfigimg" src="/files/ftp_upload/58235/58235fig5.jpg"> 图 5.tribocorrosion 机的照片在测试中, indentor 探针是在样品表面上移动的相互运动。<a href="https://www.jove.com/files/ftp_upload/58235/58235fig5large.jpg" target="_blank">请单击此处查看此图的较大版本.</a>
<img alt="Figure 6" class="xfigimg" src="/files/ftp_upload/58235/58235fig6.jpg"> 图 6.tribocorrosion 试验后的磨损轨迹扫描电镜图像。虚线表示磨损轨道的边界。<a href="https://www.jove.com/files/ftp_upload/58235/58235fig6large.jpg" target="_blank">请单击此处查看此图的较大版本.</a>
<img alt="Figure 7" class="xfigimg" src="/files/ftp_upload/58235/58235fig7.jpg"> 图 7.轮廓 tribocorrosion 试验后铝薄膜的典型磨损轨迹剖面。<a href="https://www.jove.com/files/ftp_upload/58235/58235fig7large.jpg" target="_blank">请单击此处查看此图的较大版本.</a>
<img alt="Figure 8" class="xfigimg" src="/files/ftp_upload/58235/58235fig8.jpg"> 图 8.不同应用电位下铝薄膜 tribocorrosion 率的研究综述。箭头栏表示来自所有重复测试结果的一个标准偏差。<a href="https://www.jove.com/files/ftp_upload/58235/58235fig8large.jpg" target="_blank">请单击此处查看此图的较大版本.</a>
<img alt="Figure 9" class="xfigimg" src="/files/ftp_upload/58235/58235fig9.jpg"> 图 9.tribocorrosion 率 (T)、磨损率 (W0)、腐蚀速率 (C0) 和铝薄膜的磨损腐蚀协同作用的总结。箭头栏表示来自所有重复测试结果的一个标准偏差。<a href="https://www.jove.com/files/ftp_upload/58235/58235fig9large.jpg" target="_blank">请单击此处查看此图的较大版本.</a>
<img alt="Figure 10" class="xfigimg" src="/files/ftp_upload/58235/58235fig10.jpg"> 图 10.tribocorrosion 铝薄膜在泛化试验中腐蚀电位的演变。<a href="https://www.jove.com/files/ftp_upload/58235/58235fig10large.jpg" target="_blank">请单击此处查看此图的较大版本.</a>
<img alt="Figure 11" class="xfigimg" src="/files/ftp_upload/58235/58235fig11.jpg"> 图 11.COF 在铝薄膜 tribocorrosion 试验过程中摩擦系数的演变。<a href="https://www.jove.com/files/ftp_upload/58235/58235fig11large.jpg" target="_blank">请单击此处查看此图的较大版本.</a>
<img alt="Figure 12" class="xfigimg" src="/files/ftp_upload/58235/58235fig12.jpg"> 图 12.200 mV 以上的铝薄膜 tribocorrosion 试验中腐蚀电流的演变。<a href="https://www.jove.com/files/ftp_upload/58235/58235fig12large.jpg" target="_blank">请单击此处查看此图的较大版本.</a>
<img alt="Figure 13" class="xfigimg" src="/files/ftp_upload/58235/58235fig13.jpg"> 图 13.tribocorrosion 试验中铝薄膜的机械和化学磨损总结 200 mV 以上。<a href="https://www.jove.com/files/ftp_upload/58235/58235fig13large.jpg" target="_blank">请单击此处查看此图的较大版本.</a>

Watch this Scientific Journal Video about Determining Tribocorrosion Rate and Wear-Corrosion Synergy of Bulk and Thin Film Aluminum Alloys at JoVE.com

Determining Tribocorrosion Rate and Wear-Corrosion Synergy of Bulk and Thin Film Aluminum Alloys

在这里, 我们提出了一个协议, 以测量在室温下模拟海水中的薄膜和散装铝合金的 tribocorrosion 率和磨损腐蚀协同作用。

Tribocorrosion 和薄膜铝合金的磨损与腐蚀协同性测定

The increasing complexity and severity of service conditions in areas, such as aerospace and marine industries, nuclear systems, microelectronics, ...

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Potential Energy and Energy Conservation

SCIENTISTS IN ACTION

11.2K 次观看.  University of South Florida. 在这里, 我们提出了一个协议, 以测量在室温下模拟海水中的薄膜和散装铝合金的 tribocorrosion 率和磨损腐蚀协同作用。

视频: Determining Tribocorrosion Rate and Wear-Corrosion Synergy of Bulk and Thin Film Aluminum Alloys

Potentiodynamic Corrosion Testing

Different metallic materials have different polarization characteristics as dictated by the open circuit potential, breakdown potential, and passivation potential of the material. The detection of these electrochemical parameters identifies the corrosion factors of a material. A reliable and well-functioning corrosion system is required to achieve this.
Corrosion of the samples was achieved via a potentiodynamic polarization technique employing a three-electrode configuration, consisting of reference, counter, and working electrodes. Prior to commencement a baseline potential is obtained. Following the stabilization of the corrosion potential (Ecorr), the applied potential is ramped at a slow rate in the positive direction relative to the reference electrode. The working electrode was a stainless steel screw. The reference electrode was a standard Ag/AgCl. The counter electrode used was a platinum mesh. Having a reliable and well-functioning in vitro corrosion system to test biomaterials provides an in-expensive technique that allows for the systematic characterization of the material by determining the breakdown potential, to further understand the material's response to corrosion. The goal of the protocol is to set up and run an in vitro potentiodynamic corrosion system to analyze pitting corrosion for small metallic medical devices.

Here, we present a protocol to set up and run an in vitro potentiodynamic corrosion system to analyze pitting corrosion for small metallic medical devices.

动电位腐蚀试验

Different metallic materials have different polarization characteristics as dictated by the open circuit potential, breakdown potential, and passivation ...

科研

环境科学

Experiments on Ultrasonic Lubrication Using a Piezoelectrically-assisted Tribometer and Optical Profilometer

Friction and wear are detrimental to engineered systems. Ultrasonic lubrication is achieved when the interface between two sliding surfaces is vibrated at a frequency above the acoustic range (20 kHz). As a solid-state technology, ultrasonic lubrication can be used where conventional lubricants are unfeasible or undesirable. Further, ultrasonic lubrication allows for electrical modulation of the effective friction coefficient between two sliding surfaces. This property enables adaptive systems that modify their frictional state and associated dynamic response as the operating conditions change. Surface wear can also be reduced through ultrasonic lubrication. We developed a protocol to investigate the dependence of friction force reduction and wear reduction on the linear sliding velocity between ultrasonically lubricated surfaces. A pin-on-disc tribometer was built which differs from commercial units in that a piezoelectric stack is used to vibrate the pin at 22 kHz normal to the rotating disc surface. Friction and wear metrics including effective friction force, volume loss, and surface roughness are measured without and with ultrasonic vibrations at a constant pressure of 1 to 4 MPa and three different sliding velocities: 20.3, 40.6, and 87 mm/sec. An optical profilometer is utilized to characterize the wear surfaces. The effective friction force is reduced by 62% at 20.3 mm/sec. Consistently with existing theories for ultrasonic lubrication, the percent reduction in friction force diminishes with increasing speed, down to 29% friction force reduction at 87 mm/sec. Wear reduction remains essentially constant (49%) at the three speeds considered.

We present a protocol for using a piezoelectrically-assisted tribometer and optical profilometer to investigate the dependence of ultrasonic wear and friction reduction on linear velocity, contact pressure, and surface properties.

使用超声波润滑实验一压电辅助摩擦试验机和光学轮廓

Friction and wear are detrimental to engineered systems. Ultrasonic lubrication is achieved when the interface between two sliding surfaces is vibrated at ...

工程学

Knowledge Based Cloud FE Simulation of Sheet Metal Forming Processes

The use of Finite Element (FE) simulation software to adequately predict the outcome of sheet metal forming processes is crucial to enhancing the efficiency and lowering the development time of such processes, whilst reducing costs involved in trial-and-error prototyping. Recent focus on the substitution of steel components with aluminum alloy alternatives in the automotive and aerospace sectors has increased the need to simulate the forming behavior of such alloys for ever more complex component geometries. However these alloys, and in particular their high strength variants, exhibit limited formability at room temperature, and high temperature manufacturing technologies have been developed to form them. Consequently, advanced constitutive models are required to reflect the associated temperature and strain rate effects. Simulating such behavior is computationally very expensive using conventional FE simulation techniques.
This paper presents a novel Knowledge Based Cloud FE (KBC-FE) simulation technique that combines advanced material and friction models with conventional FE simulations in an efficient manner thus enhancing the capability of commercial simulation software packages. The application of these methods is demonstrated through two example case studies, namely: the prediction of a material's forming limit under hot stamping conditions, and the tool life prediction under multi-cycle loading conditions.

The following paper presents a novel FE simulation technique (KBC-FE), which reduces computational cost by performing simulations on a cloud computing environment, through the application of individual modules. Moreover, it establishes a seamless collaborative network between world leading scientists, enabling the integration of cutting edge knowledge modules into FE simulations.

板料成形过程的知识基于云的有限元模拟

The use of Finite Element (FE) simulation software to adequately predict the outcome of sheet metal forming processes is crucial to enhancing the ...

Metal Corrosion and the Efficiency of Corrosion Inhibitors in Less Conductive Media

Material corrosion can be a limiting factor for different materials in many applications. Thus, it is necessary to better understand corrosion processes, prevent them and minimize the damages associated with them. One of the most important characteristics of corrosion processes is the corrosion rate. The measurement of corrosion rates is often very difficult or even impossible especially in less conductive, non-aqueous environments such as biofuels. Here, we present five different methods for the determination of corrosion rates and the efficiency of anti-corrosion protection in biofuels: (i) a static test, (ii) a dynamic test, (iii) a static test with a reflux cooler and electrochemical measurements (iv) in a two-electrode arrangement and (v) in a three-electrode arrangement. The static test is advantageous due to its low demands on material and instrumental equipment. The dynamic test allows for the testing of corrosion rates of metallic materials at more severe conditions. The static test with a reflux cooler allows for the testing in environments with higher viscosity (e.g., engine oils) at higher temperatures in the presence of oxidation or an inert atmosphere. The electrochemical measurements provide a more comprehensive view on corrosion processes. The presented cell geometries and arrangements (the two-electrode and three-electrode systems) make it possible to perform measurements in biofuel environments without base electrolytes that could have a negative impact on the results and load them with measurement errors. The presented methods make it possible to study the corrosion aggressiveness of an environment, the corrosion resistance of metallic materials, and the efficiency of corrosion inhibitors with representative and reproducible results. The results obtained using these methods can help to understand corrosion processes in more detail to minimize the damages caused by corrosion.

The testing of processes associated with material corrosion can often be difficult especially in non-aqueous environments. Here, we present different methods for short-term and long-term testing of corrosion behavior of non-aqueous environments such as biofuels, especially those containing bioethanol.

金属腐蚀与腐蚀抑制剂在低导电介质中的效率

Material corrosion can be a limiting factor for different materials in many applications. Thus, it is necessary to better understand corrosion processes, ...

The Evolution of Silica Nanoparticle-polyester Coatings on Surfaces Exposed to Sunlight

Corrosion of metallic surfaces is prevalent in the environment and is of great concern in many areas, including the military, transport, aviation, building and food industries, amongst others. Polyester and coatings containing both polyester and silica nanoparticles (SiO2NPs) have been widely used to protect steel substrata from corrosion. In this study, we utilized X-ray photoelectron spectroscopy, attenuated total reflection infrared micro-spectroscopy, water contact angle measurements, optical profiling and atomic force microscopy to provide an insight into how exposure to sunlight can cause changes in the micro- and nanoscale integrity of the coatings. No significant change in surface micro-topography was detected using optical profilometry, however, statistically significant nanoscale changes to the surface were detected using atomic force microscopy. Analysis of the X-ray photoelectron spectroscopy and attenuated total reflection infrared micro-spectroscopy data revealed that degradation of the ester groups had occurred through exposure to ultraviolet light to form COO&#903;, -H2C&#903;, -O&#903;, -CO&#903; radicals. During the degradation process, CO and CO2 were also produced.

Two types of surfaces, polyester-coated steel and polyester coated with a layer of silica nanoparticles, were studied. Both surfaces were exposed to sunlight, which was found to cause substantial changes in the chemistry and nanoscale topography of the surface.

表面上的纳米硅聚酯涂料暴露在阳光下的演变

Corrosion of metallic surfaces is prevalent in the environment and is of great concern in many areas, including the military, transport, aviation, ...

Determining the Chemical Composition of Corrosion Inhibitor/Metal Interfaces with XPS: Minimizing Post Immersion Oxidation

An approach for acquiring more reliable X-ray photoelectron spectroscopy data from corrosion inhibitor/metal interfaces is described. More specifically, the focus is on metallic substrates immersed in acidic solutions containing organic corrosion inhibitors, as these systems can be particularly sensitive to oxidation following removal from solution. To minimize the likelihood of such degradation, samples are removed from solution within a glove box purged with inert gas, either N2 or Ar. The glove box is directly attached to the load-lock of the ultra-high vacuum X-ray photoelectron spectroscopy instrument, avoiding any exposure to the ambient laboratory atmosphere, and thus reducing the possibility of post immersion substrate oxidation. On this basis, one can be more certain that the X-ray photoelectron spectroscopy features observed are likely to be representative of the in situ submerged scenario, e.g. the oxidation state of the metal is not modified.

A protocol to avoid the oxidation of metallic substrates during sample transfer from an inhibited acidic solution to an X-ray photoelectron spectrometer is presented.

确定缓蚀剂/金属界面的化学成分与XPS:最小化后浸入氧化

An approach for acquiring more reliable X-ray photoelectron spectroscopy data from corrosion inhibitor/metal interfaces is described. More specifically, ...

化学

Preparation and High-temperature Anti-adhesion Behavior of a Slippery Surface on Stainless Steel

Anti-adhesion surfaces with high-temperature resistance have a wide application potential in electrosurgical instruments, engines, and pipelines. A typical anti-wetting superhydrophobic surface easily fails when exposed to a high-temperature liquid. Recently, Nepenthes-inspired slippery surfaces demonstrated a new way to solve the adhesion problem. A lubricant layer on the slippery surface can act as a barrier between the repelled materials and the surface structure. However, the slippery surfaces in previous studies rarely showed high-temperature resistance. Here, we describe a protocol for the preparation of slippery surfaces with high-temperature resistance. A photolithography-assisted method was used to fabricate pillar structures on stainless steel. By functionalizing the surface with saline, a slippery surface was prepared by adding silicone oil. The prepared slippery surface maintained the anti-wetting property for water, even when the surface was heated to 300 &#176;C. Also, the slippery surface exhibited great anti-adhesion effects on soft tissues at high temperatures. This type of slippery surface on stainless steel has applications in medical devices, mechanical equipment, etc.

Slippery surfaces provide a new way to solve the adhesion problem. This protocol describes how to fabricate slippery surfaces at high temperatures. The results demonstrate that the slippery surfaces showed anti-wetting for liquids and a remarkable anti-adhesion effect on soft tissues at high temperatures.

不锈钢滑面的制备及高温抗粘接性能研究

Anti-adhesion surfaces with high-temperature resistance have a wide application potential in electrosurgical instruments, engines, and pipelines. A ...

Imaging Corrosion at the Metal-Paint Interface Using Time-of-Flight Secondary Ion Mass Spectrometry

Corrosion developed at the paint and aluminum (Al) metal-paint interface of an aluminum alloy is analyzed using time-of-flight secondary ion mass spectrometry (ToF-SIMS), illustrating that SIMS is a suitable technique to study the chemical distribution at a metal-paint interface. The painted Al alloy coupons are immersed in a salt solution or exposed to air only. SIMS provides chemical mapping and 2D molecular imaging of the interface, allowing direct visualization of the morphology of the corrosion products formed at the metal-paint interface and mapping of the chemical after corrosion occurs. The experimental procedure of this method is presented to provide technical details to facilitate similar research and highlight pitfalls that may be encountered during such experiments.

Time-of-flight secondary ion mass spectrometry is applied to demonstrate the chemical mapping and corrosion morphology at the metal-paint interface of an aluminum alloy after being exposed to a salt solution compared with a specimen exposed to air.

利用飞行时二次离子质谱法成像金属颜料界面的腐蚀

Corrosion developed at the paint and aluminum (Al) metal-paint interface of an aluminum alloy is analyzed using time-of-flight secondary ion mass ...

Hydrogen Charging of Aluminum using Friction in Water

A new method of hydrogen charging of aluminum was developed by means of a friction in water (FW) procedure. This procedure can easily introduce high amounts of hydrogen into aluminum based on the chemical reaction between water and non-oxide coated aluminum.

In order to introduce high amounts of hydrogen in aluminum and aluminum alloys, a new method of hydrogen charging was developed, called the friction in water procedure.

利用水中摩擦力对铝进行氢充电

A new method of hydrogen charging of aluminum was developed by means of a friction in water (FW) procedure. This procedure can easily introduce high ...

Co-localizing Kelvin Probe Force Microscopy with Other Microscopies and Spectroscopies: Selected Applications in Corrosion Characterization of Alloys

Kelvin probe force microscopy (KPFM), sometimes referred to as surface potential microscopy, is the nanoscale version of the venerable scanning Kelvin probe, both of which measure the Volta potential difference (VPD) between an oscillating probe tip and a sample surface by applying a nulling voltage equal in magnitude but opposite in sign to the tip-sample potential difference. By scanning a conductive KPFM probe over a sample surface, nanoscale variations in surface topography and potential can be mapped, identifying likely anodic and cathodic regions, as well as quantifying the inherent material driving force for galvanic corrosion.
Subsequent co-localization of KPFM Volta potential maps with advanced scanning electron microscopy (SEM) techniques, including back scattered electron (BSE) images, energy dispersive spectroscopy (EDS) elemental composition maps, and electron backscattered diffraction (EBSD) inverse pole figures can provide further insight into structure-property-performance relationships. Here, the results of several studies co-localizing KPFM with SEM on a wide variety of alloys of technological interest are presented, demonstrating the utility of combining these techniques at the nanoscale to elucidate corrosion initiation and propagation.
Important points to consider and potential pitfalls to avoid in such investigations are also highlighted: in particular, probe calibration and the potential confounding effects on the measured VPDs of the testing environment and sample surface, including ambient humidity (i.e., adsorbed water), surface reactions/oxidation, and polishing debris or other contaminants. Additionally, an example is provided of co-localizing a third technique, scanning confocal Raman microscopy, to demonstrate the general applicability and utility of the co-localization method to provide further structural insight beyond that afforded by electron microscopy-based techniques.

Kelvin probe force microscopy (KPFM) measures surface topography and differences in surface potential, while scanning electron microscopy (SEM) and associated spectroscopies can elucidate surface morphology, composition, crystallinity, and crystallographic orientation. Accordingly, the co-localization of SEM with KPFM can provide insight into the effects of nanoscale composition and surface structure on corrosion.

开尔文探针力显微镜与其他显微镜和光谱学共定位:合金腐蚀表征中的选定应用

Kelvin probe force microscopy (KPFM), sometimes referred to as surface potential microscopy, is the nanoscale version of the venerable scanning Kelvin ...