| 1. |
- Rasmussen, A.A., et al.
(författare)
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Microstructure in electrodeposited copper layers, the role of the substrate
- 2001
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Ingår i: Electrochimica Acta. - 0013-4686 .- 1873-3859. ; 47:1, s. 67-74
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Tidskriftsartikel (refereegranskat)abstract
- The microstructures of Cu layers, ranging in thickness from 3 to 12 µm, were investigated. The layers were electrodeposited from an acidic copper electrolyte onto two distinct substrate materials important for the micro-components industry: an Au layer with a pronounced <111>-texture, and a nano-crystalline Ni-P layer. The evolutions of surface topography, morphology and crystallographic texture in the layers were investigated with scanning electron microscopy (SEM), transmission electron microscopy (TEM) and X-ray diffraction analysis, respectively. Distinct surface topographies were observed for Cu layers deposited on the Au and Ni-P substrates. Deposition onto the Au substrate resulted in a very smooth surface of all Cu layers, whereas the Ni-P substrate caused an irregular surface for 3-µm-thick layers of Cu. The crystallographic texture in the Cu layers in the first few micrometres depended strongly on the crystallographic texture in the substrate. The Cu crystallites inherited the <111>-orientation of the Au substrate, whilst no preferred crystallographic orientation was observed in the Cu crystallites on the nano-crystalline Ni-P substrate. For Cu layers thicker than 3 µm a <110>-fibre texture developed on both the substrates. © 2001 Elsevier Science Ltd. All rights reserved.
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| 2. |
- Jensen, J.A.D., et al.
(författare)
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Electrochemically deposited nickel membranes, process-microstructure-property relationships
- 2003
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Ingår i: Surface & Coatings Technology. - 0257-8972 .- 1879-3347. ; 172:1, s. 79-89
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Tidskriftsartikel (refereegranskat)abstract
- This paper reports on the manufacturing, surface morphology, internal structure and mechanical properties of Ni-foils used as membranes in reference-microphones. Two types of foils, referred to as S-type and 0-type foils, were electrochemically deposited from a Watts-type electrolyte, with (S-type) or without (0-type) the use of the sulfur-containing additive sodium saccharin. Both types of Ni-foils appeared perfectly smooth when investigated with scanning electron microscopy (SEM), while atomic force microscopy (AFM) and transmission electron microscopy (TEM) revealed differences in the surface morphologies and a smaller grain-size in the S-type foils. X-Ray diffraction showed a <311> texture component in both types of Ni-foils, most pronounced for 0-type foils. A minor <111> texture component observed in both foil types was strongest in the S-type foils. Mechanically 0-type foils proved more ductile than S-type foils during thin film tensile testing, due to microstructural defects caused by sodium saccharin during deposition. Tensile strengths in the order of 700-1000 MPa were observed - highest for the more ductile 0-type foils. A hardness in the order of 6 GPa (590 HV) was found by nanoindentation. © 2003 Elsevier Science B.V. All rights reserved.
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| 3. |
- Andersson, Nils-Eric, 1970-
(författare)
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Structure and properties of thick plate and near surface properties after high speed machining af AA7010
- 2003
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Doktorsavhandling (övrigt vetenskapligt/konstnärligt)abstract
- Using thick plates instead of forgings in the aircraft industry for integral construction of load carrying components is becoming more and more practice. The reasons are shorter lead-times from design of a modified or totally new component to introduction in an aircraft and smaller variations in properties for plate compared to forging. The concept of integral construction also reduces the assembly time. The complex shaped components are prepared by machining pieces of thick plate. The thicker the plate the larger components can be made in one piece. Machining components from blocks of material cut from thick plate means removal of a lot of material compared to machining of near final shape forgings. A change in machining concept to high speed machining leads to higher productivity and makes thin walled sections possible to manufacture due to decreased cutting forces.Variation of through thickness structure and properties of 7010-T7451/2 as 100, 150 and 200 mm thick plates has been investigated. Through thickness crystallographic texture, degree of recrystallisation, distribution of inclusions, chemical composition and grain size has been mapped out. The observed structure is taken into account in order to explain variations of properties like yield strength; fracture toughness and fatigue crack growth resistance. Equipment used in the work of characterising the structure has been EBSP, SEM, X-ray diffraction and optical microscopy. Equipment used for evaluating mechanical properties is screw machines, servo hydraulic machines and hardness indentors.The plates show a strong through thickness texture gradient that influence the yield strength. The yield strength is also dependent on chemical composition and quench rate. Recrystallisation did not show any significant influence on yield strength or fracture toughness. The grain morphology together with quench rate is of importance for the fracture toughness and the fatigue crack growth resistance.Properties of down cut milled surfaces on thin sections using a conventional machining concept and the concept of high speed machining at various cutting speeds have been compared. The same has been done for facemilled surfaces using conventional tools and inserts at cutting speeds varying from 500 m/min up to 5000 m/min. The property of most interest is the high cycle fatigue strength. The influence of surface roughness, residual stresses and hardness on the fatigue strength has been investigated. In order to try to gain a little more information about the near surface properties x-ray diffraction studies at grazing angle incidence has been undertaken.
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| 4. |
- Du, H., et al.
(författare)
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Microstructural and compositional evolution of compound layers during gaseous nitrocarburizing
- 2000
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Ingår i: Metallurgical and Materials Transactions. A. - : Springer Science and Business Media LLC. - 1073-5623 .- 1543-1940. ; 31:1, s. 195-211
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Tidskriftsartikel (refereegranskat)abstract
- Compound layers developed at 848 K during gaseous nitrocarburizing of iron and iron-carbon specimens were investigated for several combinations of N and C activities imposed at the specimen surface by gas mixtures of NH3, N-2, CO2, and CO. The microstructural evolution of the compound layer was studied by light microscopy and by X-raydiffraction analysis. Composition-depth profiles were determined by electron probe (X-ray) microanalysis. Layer growth kinetics was investigated by layer thickness measurements. The influence Of the N and C activities on the microstructural and compositional evolution and the growth kinetics of the compound layers formed is discussed for the iron substrate. The results indicate that the microstructure is governed by a fast C and a slow N absorption at the surface in an early stage of gaseous nitrocarburizing. The influence of carbon in the substrate on the microstructural and compositional evolutions and on the growth kinetics was evaluated from comparing the results obtained for: a: normalized Fe-0.8C alloy with those for iron under identical nitrocarburizing conditions.
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| 5. |
- Pantleon, Karen, et al.
(författare)
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X-ray diffraction investigation of electrochemically deposited copper
- 2004
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Ingår i: Materials Science Forum. - 0255-5476 .- 1662-9752. ; 443-4, s. 201-204
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Tidskriftsartikel (refereegranskat)abstract
- Copper layers were deposited from acidic electrolytes containing different amounts of organic additives, designed for the formation of Cu-interconnect structures. Amorphous Ni-P substrates allow to study the unbiased growth of the electrodeposits. The crystallographic texture was investigated by the determination of X-ray diffraction (XRD) pole figures and the calculation of the orientation distribution functions. XRD results are discussed in relation to the morphologies of the electrodeposits as investigated with light optical microscopy and correlated with the process parameters during electrodeposition.
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