This research was supported by the European Union's Seventh Framework Programme (FP7/2007-2013) under grant agreement No. 604240, project title "An industrial system enabling the use of a patented, lab-proven materials processing technology for Low Cost forming of Lightweight structures for transportation industries (LoCoLite)."

1.试样的制备<ol><li>机平坦狗骨和使用激光切割机和一个计算机数字控制（CNC）铣床（对于在不同的应变路径包括单轴，平面应变成形性试验从市售材料的铝合金6082（AA6082）十字形标本和等双轴应变状态）。 </li><li>测量每个十字形试和每个狗骨样品的厚度用游标卡尺三次在中央计区域，并计算平均值。确保在一个十字形试测量部分的厚度为0.7±0.05mm与该单轴试样的厚度为1.5±0.1毫米。 </li><li>通过使用耐火，黑色喷漆（能够承受的温度高达1093℃下的）喷漆十字形样品的整个顶表面。等到油漆变干，然后从手臂的长度来创建一个随机喷洒阻燃，白色油漆点喷雾图案由DIC系统识别（参见图1中的例子）。 </li><li>焊接的一对热电偶到后表面的中心（相对的涂漆的表面）的样品的。将热电偶连接到单轴试验机的反馈温度控制系统的另一端，以监视和控制的温度变化的历史。 </li></ol> 2.双轴试验设备的组装<ol><li>组装该双轴测试装置的所有部分，包括一个底板，一个中心轴，输入和输出可旋转板，车厢，夹具，导轨，和刚性的连接杆（组装装置示于图2）。 <ol><li>输入可旋转板直接使用连接杆，连接到电阻加热单轴拉伸试验机，它提供了单轴拉伸力的可动夹爪。耦合输入可旋转板的中心驱动轴和夫妇该中心驱动轴与输出可旋转板。 </li><li>确保围绕旋转轴线的可旋转输入盘的旋转而旋转的驱动轴，从而旋转输出旋转板其所围绕旋转轴线被耦合。 </li><li>在一个端部，一对每个刚性连接杆对输出可旋转板连接点中的一个的。夫妇的另一端连接到车厢中的一个。 注意:这将引起车厢与试样保持器滑动来回沿导轨以低摩擦，这可以应用双轴力到十字形样品。 </li><li>使用螺栓，所述十字形样品的每个臂夹紧到与试样保持器和顶板的滑架。 </li></ol></li><li>在单轴拉伸试验机的腔室设置把手， 如图3（a）中 。将四个焊接电缆到每对夹具的，这是由不锈钢和铜，respe沉着应对，因此，焊接电缆连接到电源。 注意:所述焊接电缆的导体面积为50mm 2和电流额定值是345 A. <ol><li>把夹具和双轴测试设备到单轴拉伸试验机的两个夹具的夹具和他们的内部拧紧（ 图3（a））。 </li></ol></li><li>在单轴拉伸试验机的腔室设置双轴测试装置， 如图3（b）中 。 <ol><li>使用两个帧，并且在顶部螺栓与底板的底侧固定装置在单轴拉伸试验机的腔室。 </li><li>把样品插入到样品支架上的双轴测试装置的顶部。 </li><li>所述焊接电缆的每个端子连到检查体的每个夹紧区域。 </li></ol></li></ol> 3.加热淬火系统的设置<ol><li>紧密合作nnect试样的每个夹紧区域到不锈钢顶板，其用作电阻加热的电极。 </li><li>拧紧与压接环端子焊接电缆连接到每个夹紧区域的顶板。 </li><li>连接在8000公斤/米2的压力，用于冷却喇叭形与软管喷嘴与调节的空气供给高流量骤冷系统。 </li><li>使用四个喷嘴以从试样的臂吹送空气到样本的中心区域。 注:喷嘴不引导到测量部分，用于冷却以避免阻塞从相机的视图中的中央区域。 </li></ol> 4. DIC系统的设置<ol><li>该DIC系统的高速相机连接用微透镜到计算机。调整相机的帧速率，以每秒25帧，50帧，并且从帧速率的菜单（用于以0.01 / s时，0.1 / s和1 / s时，分别在拉伸应变速率下测试）500帧。将所有我的决议法师到1280×1024像素。 注:帧速率取决于数据点收集的数量;至少200个数据点可以使用上述的设置来收集。 </li><li>使用一个额外的聚光灯下300 W的在高应变率测试电源。直接在单轴拉伸试验机的腔室指向聚光灯。 </li><li>调整相机镜头，使得它平行于所述室中的样品的顶部表面和聚焦相机上的测量部分。 </li></ol> 5.实验计划<ol><li>运行阻力通过点击在控制软件的三角运行按钮加热单轴拉伸试验机。 注:电力贯穿AA6082材料和以30℃/秒的加热速率加热到49的535°C 14的固溶热处理温度。该材料在535℃下浸泡1分钟，这是足够的析出物的全分辨率。嗳ř从急冷系统吹用于在在370-510℃的范围内100℃/秒15到一个3指定升高的温度下的冷却速度，淬灭材料。 </li><li>伸展用双轴测试装置试样在0.01-1 /秒的范围内的恒定应变速率和通过手动按压连接到高速照相机触发按钮记录变形历史。 注:从单轴试验机的输入位移双轴试验装置由单轴试验机的内置软件控制。 </li><li>在由单轴不同应变路径，平面应变，和双轴应变状态3通过调整双轴测试装置的结构进行测试。 <ol><li>断开单轴测试两个相对的连接杆。夹紧在双轴测试装置狗骨样品，并将其连接到焊接电缆，如在步骤3.1-3。4.重复步骤5.1-5.2。 </li><li>固定两个相对的滑架与螺栓的底板，以限制对平面应变状态下的检测相应的方向上的变形。夹紧在双轴测试装置十字形样品，并将其连接到焊接电缆，如步骤3.1-3.4。重复步骤5.1-5.2。 </li></ol></li><li>对于每个测试条件重复步骤5.3.1-5.3.2三次，使用新的狗骨和十字形标本。 </li></ol> 6.数据处理<ol><li>导入由高速照相机记录到后处理软件的所有图像和根据软件手册遵循标准步骤进行数据分析。 </li><li>使用ISO标准3，以确定通过点击软件的FLC模式按钮形成限制。 注:此方法已经被集成到图像相关处理软件。 </li><li>标记在不同温度下的成形限制每个结果在图中S，应变率，和应变路径。 </li><li>绘制在所有测试条件下的成形极限曲线，得到的合金的FLD热冲压条件下进行。 </li></ol>

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The authors have nothing to disclose.

用于确定成形限制常规的成形性的测试方法是通常只在室温下适用。所呈现的技术可用于通过引入新颖的双轴测试设备到电阻加热单轴试验机来评价金属用于热片冲压应用的可成形性。这可以不使用用于热冲压应用的常规方法来进行。加热和冷却系统和DIC系统的设置是为了控制在样品温度分布的均匀性，并因此记录拉伸试样的变形历史的关键。 在该技术中，加热和冷却速率?...

汽车行业正面临着降低燃油消耗和车辆排放减少环境污染的一个巨大的全球性挑战。轻量化对提高汽车的性能是有益的，并且可以直接降低能耗1。由于金属板在室温下，热冲压和冷模淬火工艺低的可成形性（称为热冲压）2用于改进合金的成形性并因此获得在汽车应用中复杂形状的部件。 成形极限图（FLD）是评价的合金3的成形性的有用工具。外的平面的测试，如测试Nakazima 4， 图5和面内测试，如测试Marciniak 6，7，8，一个再常规的实验方法，以获得各种条件9，10，11下的金属板的成形极限。甲伺服液压双轴测试机也已经用于研究合金在室温下12，13中的可成形性。 然而，没有上述方法适用于热冲压条件下的可成形性的测试中，因为与加热和冷却速率的控制一起，需要成形之前的冷却过程。变形温度和应变速率很难获得准确。因此，一种新的成形性的测试系统是在本研究中提出的通过实验来确定片材金属的热冲压条件下成形极限。

<table border="0" cellpadding="0" cellspacing="0" width="923">
	<colgroup>
		<col />
		<col />
		<col />
		<col />
	</colgroup>
	<tbody>
		<tr height="21">
			<td height="21" style="height:21px;width:229px;">Aluminium Alloy&#160;</td>
			<td style="width:152px;">Smiths Metal</td>
			<td style="width:121px;">6082</td>
			<td style="width:421px;">Specimens machining</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:229px;">Laser cutter</td>
			<td style="width:152px;">LVD Ltd</td>
			<td style="width:121px;">HELIUS 25/13</td>
			<td>Laser cutting specimens</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:229px;">CNC machine</td>
			<td style="width:152px;">HAAS Automation</td>
			<td style="width:121px;">TM-2CE</td>
			<td>Machine specimens by milling</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:229px;">Vernier caliper</td>
			<td style="width:152px;">Mitutoyo</td>
			<td style="width:121px;">575-481</td>
			<td>Thickness measurement</td>
		</tr>
		<tr height="42">
			<td height="42" style="height:42px;width:229px;">Resistance heating uniaxial testing machine</td>
			<td style="width:152px;">Dynamic System Inc</td>
			<td style="width:121px;">Gleeble 3800</td>
			<td>Thermo-mechanical materials simulator</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:229px;">High flow quench system</td>
			<td style="width:152px;">Dynamic System Inc</td>
			<td style="width:121px;">38510</td>
			<td>For air cooling</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:229px;">Thermocouples</td>
			<td style="width:152px;">Dynamic System Inc</td>
			<td style="width:121px;">K type</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:229px;">Nozzles</td>
			<td style="width:152px;">Indexa</td>
			<td style="width:121px;"></td>
			<td>Nozzle flared 1/4 inch bore</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:229px;">Welding cables</td>
			<td style="width:152px;">LAPP Group</td>
			<td style="width:121px;">H01N2-D</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:229px;">High-speed camera</td>
			<td style="width:152px;">Photron</td>
			<td style="width:121px;">UX50</td>
			<td>For DIC testing</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:229px;">Camera lens</td>
			<td style="width:152px;">Nikon</td>
			<td style="width:121px;">Micro 200mm</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:229px;">Lamp</td>
			<td style="width:152px;">Liliput</td>
			<td style="width:121px;">150ce</td>
			<td>300W</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:229px;">Laptop</td>
			<td style="width:152px;">HP</td>
			<td style="width:121px;">Campaq 2530p</td>
			<td>For images recording</td>
		</tr>
		<tr height="42">
			<td height="42" style="height:42px;width:229px;">Biaxial testing apparatus</td>
			<td style="width:152px;">Manufactured independently</td>
			<td style="width:121px;"></td>
			<td style="width:421px;">All parts were designed and machinced by authors for biaxial testing</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;width:229px;">Steel&#160;</td>
			<td style="width:152px;">West Yorkshire Steel</td>
			<td style="width:121px;">H13</td>
			<td style="width:421px;">Mateials of the biaxial testing apparatus</td>
		</tr>
		<tr height="42">
			<td height="42" style="height:42px;width:229px;">Image correlation processing software</td>
			<td style="width:152px;">GOM</td>
			<td style="width:121px;">ARAMIS</td>
			<td>Non-contact measuring system and data post-pocessing</td>
		</tr>
	</tbody>
</table>

a novel biaxial testing apparatus for the determination of forming limit under hot stamping conditions

热冲压和冷模淬火工艺越来越多地用于形成金属片的复杂形状的结构部件。常规的实验方法，如外的平面和平面内的测试中，并不适用于加热和快速冷却处理之前形成用于热冲压条件下进行测试时引入成形极限的确定。一种新颖的平面内双轴测试系统的设计和用于形成在电阻加热单轴试验机加热和冷却过程后的不同应变路径，温度和应变率的金属板的限制的确定。双轴测试系统的核心部分是一个双轴设备，其传送由单轴试验机提供到双轴力的单轴力。十字形样品的一种类型被设计和验证的使用提出的双轴测试系统铝合金6082的成形性试验。数字IM使用年龄相关性（DIC）系统用高速照相机对变形期间采取的试样的应变测量。提出该双轴测试系统的目的是使合金的成形极限，在热冲压条件下各种温度和应变速率来确定。

由于成形极限是高度应变路径依赖性的，对于每个测试条件下的应变路径的线性通过分析DIC结果验证;应变路径是整个变形对于每个测试条件成比例的。次要到主应变比的范围是约-0.37（单轴条件）至0.26（近双轴条件）。通过处理用于不同AA6082条件的数据，形成用于不同应变路径限制数据被确定并且因此，是通过曲线拟合获得的热冲压条件AA6082的成形极限。在图3</stro...

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A Novel Biaxial Testing Apparatus for the Determination of Forming Limit under Hot Stamping Conditions

该协议提出上的电阻，以确定热冲压条件下的金属板的成形极限图（FLD）加热单轴拉伸试验机中使用的新颖的双轴测试系统。

一种新型双轴试验设备的成形极限的下烫印条件的决定

The hot stamping and cold die quenching process is increasingly used to form complex shaped structural components of sheet metals. Conventional ...

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7.5K 次观看.  Imperial College London. 该协议提出上的电阻，以确定热冲压条件下的金属板的成形极限图（FLD）加热单轴拉伸试验机中使用的新颖的双轴测试系统。 

视频: A Novel Biaxial Testing Apparatus for the Determination of Forming Limit under Hot Stamping Conditions

Fabrication of VB2/Air Cells for Electrochemical Testing

A technique to investigate the properties and performance of new multi-electron metal/air battery systems is proposed and presented. A method for synthesizing nanoscopic VB2 is presented as well as step-by-step procedure for applying a zirconium oxide coating to the VB2 particles for stabilization upon discharge. The process for disassembling existing zinc/air cells is shown, in addition construction of the new working electrode to replace the conventional zinc/air cell anode with a the nanoscopic VB2 anode. Finally, discharge of the completed VB2/air battery is reported. We show that using the zinc/air cell as a test bed is useful to provide a consistent configuration to study the performance of the high-energy high capacity nanoscopic VB2 anode.

Fabrication of VB2/Air Cells for Electrochemical Testing

A protocol is presented to study multi-electron metal/air battery systems by using previous technology developed for the zinc/air cell. Electrochemical testing is then performed on fabricated batteries to evaluate performance.

VB制作<sub&gt; 2</sub&gt; /空气电池电化学测试

A technique to investigate the properties and performance of new multi-electron metal/air battery systems is proposed and presented. A method for ...

科研

工程学

High-Sensitivity Nuclear Magnetic Resonance at Giga-Pascal Pressures: A New Tool for Probing Electronic and Chemical Properties of Condensed Matter under Extreme Conditions

Nuclear Magnetic Resonance (NMR) is one of the most important techniques for the study of condensed matter systems, their chemical structure, and their electronic properties. The application of high pressure enables one to synthesize new materials, but the response of known materials to high pressure is a very useful tool for studying their electronic structure and developing theories. For example, high-pressure synthesis might be at the origin of life; and understanding the behavior of small molecules under extreme pressure will tell us more about fundamental processes in our universe. It is no wonder that there has always been great interest in having NMR available at high pressures. Unfortunately, the desired pressures are often well into the Giga-Pascal (GPa) range and require special anvil cell devices where only very small, secluded volumes are available. This has restricted the use of NMR almost entirely in the past, and only recently, a new approach to high-sensitivity GPa NMR, which has a resonating micro-coil inside the sample chamber, was put forward. This approach enables us to achieve high sensitivity with experiments that bring the power of NMR to Giga-Pascal pressure condensed matter research. First applications, the detection of a topological electronic transition in ordinary aluminum metal and the closing of the pseudo-gap in high-temperature superconductivity, show the power of such an approach. Meanwhile, the range of achievable pressures was increased tremendously with a new generation of anvil cells (up to 10.1 GPa), that fit standard-bore NMR magnets. This approach might become a new, important tool for the investigation of many condensed matter systems, in chemistry, geochemistry, and in physics, since we can now watch structural changes with the eyes of a very versatile probe.

Nuclear magnetic resonance is one of the most important spectroscopic tools. Here, the development of a new approach under high pressure, currently up to 10.1 GPa, is presented. This opens a new window into condensed matter physics and chemistry, where high-pressure research is of great importance.

高灵敏度核磁共振的千兆帕斯卡压力:一种新的工具，用于极端条件下探测电子和化工凝聚态的性质

Nuclear Magnetic Resonance (NMR) is one of the most important techniques for the study of condensed matter systems, their chemical structure, and their ...

A Testing Platform for Durability Studies of Polymers and Fiber-reinforced Polymer Composites under Concurrent Hygrothermo-mechanical Stimuli

The durability of polymers and fiber-reinforced polymer composites under service condition is a critical aspect to be addressed for their robust designs and condition-based maintenance. These materials are adopted in a wide range of engineering applications, from aircraft and ship structures, to bridges, wind turbine blades, biomaterials and biomedical implants. Polymers are viscoelastic materials, and their response may be highly nonlinear and thus make it challenging to predict and monitor their in-service performance. The laboratory-scale testing platform presented herein assists the investigation of the influence of concurrent mechanical loadings and environmental conditions on these materials. The platform was designed to be low-cost and user-friendly. Its chemically resistant materials make the platform adaptable to studies of chemical degradation due to in-service exposure to fluids. An example of experiment was conducted at RT on closed-cell polyurethane foam samples loaded with a weight corresponding to ~50% of their ultimate static and dry load. Results show that the testing apparatus is appropriate for these studies. Results also highlight the larger vulnerability of the polymer under concurrent loading, based on the higher mid-point displacements and lower residual failure loads. Recommendations are made for additional improvements to the testing apparatus.

The durability of polymers and fiber-reinforced polymer composites in service is a critical aspect for their designs and condition-based maintenance. We present a novel low-cost laboratory testing platform for the investigation of the influence of concurrent mechanical and environmental loadings, and may help design more efficient yet safer composite structures.

一个测试平台为聚合物的耐久性研究，并在同期Hygrothermo机械刺激纤维增强聚合物复合材料

The durability of polymers and fiber-reinforced polymer composites under service condition is a critical aspect to be addressed for their robust designs ...

Detection and Recovery of Palladium, Gold and Cobalt Metals from the Urban Mine Using Novel Sensors/Adsorbents Designated with Nanoscale Wagon-wheel-shaped Pores

Developing low-cost, efficient processes for recovering and recycling palladium, gold and cobalt metals from urban mine remains a significant challenge in industrialized countries. Here, the development of optical mesosensors/adsorbents (MSAs) for efficient recognition and selective recovery of Pd(II), Au(III), and Co(II) from urban mine was achieved. A simple, general method for preparing MSAs based on using high-order mesoporous monolithic scaffolds was described. Hierarchical cubic Ia3d wagon-wheel-shaped MSAs were fabricated by anchoring chelating agents (colorants) into three-dimensional pores and micrometric particle surfaces of the mesoporous monolithic scaffolds. Findings show, for the first time, evidence of controlled optical recognition of Pd(II), Au(III), and Co(II) ions and a highly selective system for recovery of Pd(II) ions (up to ~95%) in ores and industrial wastes. Furthermore, the controlled assessment processes described herein involve evaluation of intrinsic properties (e.g., visual signal change, long-term stability, adsorption efficiency, extraordinary sensitivity, selectivity, and reusability); thus, expensive, sophisticated instruments are not required. Results show evidence that MSAs will attract worldwide attention as a promising technological means of recovering and recycling palladium, gold and cobalt metals.

Because of the importance and extensive use of palladium, gold and cobalt metals in high-technology equipment, their recovery and recycling constitute an important industrial challenge. The metal recovery system described herein is a simple, low-cost means for the effective detection, removal, and recovery of these metals from the urban mine.

检测和钯的回收，从城市矿山黄金和钴金属使用标有纳米货车车轮形的孔隙新型传感器/吸附剂

Developing low-cost, efficient processes for recovering and recycling palladium, gold and cobalt metals from urban mine remains a significant challenge in ...

Development of an Experimental Setup for the Measurement of the Coefficient of Restitution under Vacuum Conditions

The Discrete Element Method is used for the simulation of particulate systems to describe and analyze them, to predict and afterwards optimize their behavior for single stages of a process or even an entire process. For the simulation with occurring particle-particle and particle-wall contacts, the value of the coefficient of restitution is required. It can be determined experimentally. The coefficient of restitution depends on several parameters like the impact velocity. Especially for fine particles the impact velocity depends on the air pressure and under atmospheric pressure high impact velocities cannot be reached. For this, a new experimental setup for free-fall tests under vacuum conditions is developed. The coefficient of restitution is determined with the impact and rebound velocity which are detected by a high-speed camera. To not hinder the view, the vacuum chamber is made of glass. Also a new release mechanism to drop one single particle under vacuum conditions is constructed. Due to that, all properties of the particle can be characterized beforehand.

The coefficient of restitution is a parameter that describes the loss of kinetic energy during collision. Here, a free-fall setup under vacuum conditions is developed to be able to determine the coefficient of restitution parameter for particles in micrometer range with high impact velocities.

实验装置的研制归还系数在真空条件下测量

The Discrete Element Method is used for the simulation of particulate systems to describe and analyze them, to predict and afterwards optimize their ...

Advanced Experimental Methods for Low-temperature Magnetotransport Measurement of Novel Materials

Novel electronic materials are often produced for the first time by synthesis processes that yield bulk crystals (in contrast to single crystal thin film synthesis) for the purpose of exploratory materials research. Certain materials pose a challenge wherein the traditional bulk Hall bar device fabrication method is insufficient to produce a measureable device for sample transport measurement, principally because the single crystal size is too small to attach wire leads to the sample in a Hall bar configuration. This can be, for example, because the first batch of a new material synthesized yields very small single crystals or because flakes of samples of one to very few monolayers are desired. In order to enable rapid characterization of materials that may be carried out in parallel with improvements to their growth methodology, a method of device fabrication for very small samples has been devised to permit the characterization of novel materials as soon as a preliminary batch has been produced. A slight variation of this methodology is applicable to producing devices using exfoliated samples of two-dimensional materials such as graphene, hexagonal boron nitride (hBN), and transition metal dichalcogenides (TMDs), as well as multilayer heterostructures of such materials. Here we present detailed protocols for the experimental device fabrication of fragments and flakes of novel materials with micron-sized dimensions onto substrate and subsequent measurement in a commercial superconducting magnet, dry helium close-cycle cryostat magnetotransport system at temperatures down to 0.300 K and magnetic fields up to 12 T.

We describe the methodology of mechanical exfoliation and deposition of flakes of novel materials with micron-sized dimensions onto substrate, fabrication of experimental device structures for transport experimentation, and the magnetotransport measurement in a dry helium close-cycle cryostat at temperatures down to 0.300 K and magnetic fields up to 12 T.

对于新材料的低温磁输运测量先进的实验方法

Novel electronic materials are often produced for the first time by synthesis processes that yield bulk crystals (in contrast to single crystal thin film ...

Spark Plasma Sintering Apparatus Used for the Formation of Strontium Titanate Bicrystals

A spark plasma sintering apparatus was used as a novel method for diffusion bonding of two single crystals of strontium titanate to form bicrystals with one twist grain boundary. This apparatus utilizes high uniaxial pressure and a pulsed direct current for rapid consolidation of material. Diffusion bonding of strontium titanate bicrystals without fracture, in a spark plasma sintering apparatus, is possible at high pressures due to the unusual temperature dependent plasticity behavior of strontium titanate. We demonstrate a method for the successful formation of bicrystals at accelerated time scales and lower temperatures in a spark plasma sintering apparatus compared to bicrystals formed by conventional diffusion bonding parameters. Bond quality was verified by scanning electron microscopy. A clean and atomically abrupt interface containing no secondary phases was observed using transmission electron microscopy techniques. Local changes in bonding across the boundary was characterized by simultaneous scanning transmission electron microscopy and spatially resolved electron energy-loss spectroscopy.

A viable technique for the formation of strontium titanate bicrystals at high pressure and fast heating rate via the spark plasma sintering apparatus is developed.

放电等离子烧结设备中使用的钛酸锶双晶体的形成

A spark plasma sintering apparatus was used as a novel method for diffusion bonding of two single crystals of strontium titanate to form bicrystals with ...

In Situ Visualization of the Phase Behavior of Oil Samples Under Refinery Process Conditions

To help address production issues in refineries caused by the fouling of process units and lines, we have developed a setup as well as a method to visualize the behavior of petroleum samples under process conditions. The experimental setup relies on a custom-built micro-reactor fitted with a sapphire window at the bottom, which is placed over the objective of an inverted microscope equipped with a cross-polarizer module. Using reflection microscopy enables the visualization of opaque samples, such as petroleum vacuum residues, or asphaltenes. The combination of the sapphire window from the micro-reactor with the cross-polarizer module of the microscope on the light path allows high-contrast imaging of isotropic and anisotropic media. While observations are carried out, the micro-reactor can be heated to the temperature range of cracking reactions (up to 450 &#176;C), can be subjected to H2 pressure relevant to hydroconversion reactions (up to 16 MPa), and can stir the sample by magnetic coupling. 
Observations are typically carried out by taking snapshots of the sample under cross-polarized light at regular time intervals. Image analyses may not only provide information on the temperature, pressure, and reactive conditions yielding phase separation, but may also give an estimate of the evolution of the chemical (absorption/reflection spectra) and physical (refractive index) properties of the sample before the onset of phase separation.

In Situ Visualization of the Phase Behavior of Oil Samples Under Refinery Process Conditions

This article describes a setup and method for the in situ visualization of oil samples under a variety of temperature and pressure conditions that aim to emulate refining and upgrading processes. It is primarily used for studying isotropic and anisotropic media involved in the fouling behavior of petroleum feeds.

在油样品的相行为在炼油工艺条件的原位可视化

To help address production issues in refineries caused by the fouling of process units and lines, we have developed a setup as well as a method to ...

Subsurface Defect Localization by Structured Heating Using Laser Projected Photothermal Thermography

The presented method is used to locate subsurface defects oriented perpendicularly to the surface. To achieve this, we create destructively interfering thermal wave fields that are disturbed by the defect. This effect is measured and used to locate the defect. We form the destructively interfering wave fields by using a modified projector. The original light engine of the projector is replaced with a fiber-coupled high-power diode laser. Its beam is shaped and aligned to the projector&#39;s spatial light modulator and optimized for optimal optical throughput and homogeneous projection by first characterizing the beam profile, and, second, correcting it mechanically and numerically. A high-performance infrared (IR) camera is set up according to the tight geometrical situation (including corrections of the geometrical image distortions) and the requirement to detect weak temperature oscillations at the sample surface. Data acquisition can be performed once a synchronization between the individual thermal wave field sources, the scanning stage, and the IR camera is established by using a dedicated experimental setup which needs to be tuned to the specific material being investigated. During data post-processing, the relevant information on the presence of a defect below the surface of the sample is extracted. It is retrieved from the oscillating part of the acquired thermal radiation coming from the so-called depletion line of the sample surface. The exact location of the defect is deduced from the analysis of the spatial-temporal shape of these oscillations in a final step. The method is reference-free and very sensitive to changes within the thermal wave field. So far, the method has been tested with steel samples but is applicable to different materials as well, in particular to temperature sensitive materials.

This method aims at locating vertical subsurface defects. Here, we couple a laser with a spatial light modulator and trigger its video input to heat a sample surface deterministically with two anti-phased modulated lines while acquiring highly resolved thermal images. The defect position is retrieved from evaluating thermal wave interference minima.

使用激光投射光热法构造加热的地下缺陷定位

The presented method is used to locate subsurface defects oriented perpendicularly to the surface. To achieve this, we create destructively interfering ...

Ultrasonic Fatigue Testing in the Tension-Compression Mode

Ultrasonic fatigue testing is one of a few methods which allow investigating fatigue properties in the ultra-high cycle region. The method is based on exposing the specimen to longitudinal vibrations on its resonance frequency close to 20 kHz. With use of this method, it is possible to significantly decrease the time required for the test, when compared to conventional testing devices usually working at frequencies under 200 Hz. It is also used to simulate loading of material during operation in high speed conditions, such as those experienced by components of jet engines or car turbo pumps. It is necessary to operate only in the high and ultra-high cycle region, due to the possibility of extremely high deformation rates, which can have a significant influence on the test results. Specimen shape and dimensions have to be carefully selected and calculated to fulfill the resonance condition of the ultrasonic system; thus, it is not possible to test the full components or specimens of arbitrary shape. Before each test, it is necessary to harmonize the specimen with the frequency of the ultrasonic system to compensate for deviations of the real shape from the ideal one. It is not possible to run a test until a total fracture of the specimen, since the test is automatically terminated after initiation and propagation of the crack to a certain length, when the stiffness of the system changes enough to shift the system out of the resonance frequency. This manuscript describes the process of evaluation of materials' fatigue properties at high-frequency ultrasonic fatigue loading with use of mechanical resonance at a frequency close to 20 kHz. The protocol includes a detailed description of all steps required for a correct test, including specimen design, stress calculation, harmonizing with the resonance frequency, performing the test, and final static fracture.

A protocol for ultrasonic fatigue testing in the high and ultra-high cycle region in axial tension-compression loading mode.

拉伸压缩模式下的超声疲劳试验

Ultrasonic fatigue testing is one of a few methods which allow investigating fatigue properties in the ultra-high cycle region. The method is based on ...