Nondestructive Evaluation of Thin Film Microstructures by Picosecond Ultrasonics

1988 ◽  
Vol 142 ◽  
Author(s):  
Humphrey J. Maris ◽  
Holger T. Grahn ◽  
Jan Tauc
Keyword(s):  
Thin Film ◽  
Mechanical Properties ◽  
Nondestructive Evaluation ◽  
Time Domain ◽  
Elastic Stress ◽  
Time Dependent ◽  
Ultrasonic Evaluation ◽  
Ultrasonic Measurements ◽  
Made In

AbstractWe describe a technique by which ultrasonic measurements can be made in the picosecond time domain. A light pulse (duration of the order of 0.1 psec) is absorbed at a surface, thereby setting up an elastic stress. This stress launches an elastic pulse into the interior. The propagation of this strain, including its reflection at interfaces within a microstructure, is monitored through measurements of the time-dependent changes of the optical reflectivity. These measurements are made using a time-delayed probe pulse. In these experiments the spatial length of the elastic pulses can be as short as 50 Å. We can therefore use this technique to perform a nondestructive ultrasonic evaluation of thin-film microstructures. We describe here results we have obtained which demonstrate the application of the method to the study of the mechanical properties of thin films, the geometry of microstructures, and the quality of bonding at interfaces.

scholarly journals Impact of Honeycomb Polylactide Infill% in FDM Printed PLA/Nylon for Improved Mechanical Properties

2020 ◽  
Vol 8 (5) ◽  
pp. 3662-3668
Keyword(s):  
Mechanical Properties ◽  
Additive Manufacturing ◽  
Conventional Process ◽  
Improved Accuracy ◽  
Made In

In conventional manufacturing procedures liable upon the forces acting on the materials may lead to breakage during motion of the part undergoing construct which is inevitable to no change its shape and position. In pretty much every case, materials have anisotropic by its nature and virtue. As additive manufacturing (AM) techniques embedded undergoing processes with improved accuracy of the parts being developed. Since there is far disadvantage of the quality of the AM product, constantly improvements made the process of AM is being escalating than conventional process. The assessment of the product and the complexity of the parts can’t be resolved or found before it developing a methodology which impact mechanical properties of the printed parts. An effort has been made in the present work to improve the products mechanical properties by increasing the infill percentage. Study has been carried out as in view of increased infill with elaborated percentages of 15%, 30%, 40% and 50% to enhance the mechanical properties of the parts.

Influence of Storage Conditions on Quality of Fly Ashes

2014 ◽  
Vol 1000 ◽  
pp. 59-62
Author(s):  
Hana Kalousová ◽  
Eva Bartoníčková ◽  
Tomáš Opravil
Keyword(s):  
Mechanical Properties ◽  
Fly Ash ◽  
Storage Conditions ◽  
Fly Ashes ◽  
Volume Stability ◽  
Stock Pile ◽  
Long Time ◽  
Made In

The presented paper deals with the issue of influence of storage conditions on the quality of conventional fly ashes which are produced by combustion of lignite. These ashes were stockpiled for long time. A borehole for sampling was made in the fly ash stock-pile. Total depth of the borehole was 20 m. Samples of fly ashes taken from every single meter were analyzed and next mechanical properties and the volume stability of materials containing these fly ashes were tested. The quality of fly ashes especially with respect to the possibility to use them as components of pastes, mortars and concretes as pozzolanic admixture or fine filler was evaluated.

Mechanical Testing of Additive Manufactured Metal Parts

2015 ◽  
Vol 651-653 ◽  
pp. 713-718 ◽  
Author(s):  
Marion Merklein ◽  
Raoul Plettke ◽  
Daniel Junker ◽  
Adam Schaub ◽  
Bhrigu Ahuja
Keyword(s):  
Mechanical Properties ◽  
Surface Roughness ◽  
Stainless Steel ◽  
Additive Manufacturing ◽  
Laser Beam ◽  
Round Robin Test ◽  
Metal Parts ◽  
Laser Beam Melting ◽  
Made In

The quality of additive manufactured parts however depends pretty much on the workers experience to control porosity, layer linkage and surface roughness. To analyze the robustness of the Laser Beam Melting (LBM) process a Round Robin test was made in which specimens from four institutes from different countries were tested and compared. For the tests each institute built a set of specimens out of stainless steel 1.4540. The aim of this work is to analyze the influence of the process parameters on the mechanical properties. The results show that there is a high potential for additive manufacturing but also a lot of further research is necessary to optimize this technology.

A Quantitative Evaluation of the Quality of Recycled Steel in Uganda

2012 ◽  
Author(s):  
C. Senfuka ◽  
J. B. Kirabira ◽  
J. K. Byaruhanga
Keyword(s):  
Mechanical Properties ◽  
Raw Material ◽  
Emission Spectrometry ◽  
Test Results ◽  
Geometrical Properties ◽  
Direct Reduced Iron ◽  
The Relationship ◽  
Recycled Steel ◽  
Made In

All steel made in Uganda is currently manufactured from scrap. Such steel has often been characterized by unpredictable performance in consonance with its inconsistent raw material inputs. This study evaluates and relates the mechanical, metallurgical and geometrical properties of these bars in order to identify the factors underlying the performance of the products from this steel and examine the relationship with their scrap content. In order to study the steels, tensile, torsion and micrographic tests have been carried out together with spark emission spectrometry on samples collected from different plants. The test results generally indicate impressive steel resilience, strength and metallographic properties in spite of relatively high and irregular carbon content. Limited weldability, uniaxiality of properties, uneven scatter of microelements and substantial non-uniformity of longitudinal mechanical properties have been observed. Rolling and post rolling defects have been noted. The geometric reliability of the bars has also been found generally low. Improvement of secondary refinement, use of direct reduced iron (DRI) diluent and more diligent sorting have suggested as solutions.

scholarly journals Analisis Sifat Mekanik Hasil Pengelasan SMAW dengan Akar Las Tig dan Las SMAW pada Pipa API 5L

2019 ◽  
Vol 17 (1) ◽  
pp. 37
Author(s):  
Muas M ◽  
Muhammad Arsyad Suyuti ◽  
Rasul Rasul ◽  
Patta Hajji
Keyword(s):  
Mechanical Properties ◽  
Tensile Strength ◽  
Bending Strength ◽  
Mechanical Tests ◽  
Current Variation ◽  
Root Face ◽  
A Current ◽  
Root Methods ◽  
Made In

The purpose of this research is to know the mechanical properties of the welds due to the current variation of welding joint API 5L using TIG and SMAW welding root methods. Preparation of specimens of pipe API 5L PSL1 grade X56 (Ø 177.8 mm, length 200 mm, width 7 mm), then specimens preparation were made in a single V 600, root gap 2mm, root face 2mm. Filling the welding roots with TIG welding and SMAW using electrodes E7018 with a current variation 70A, 80A, 90A. Mechanical tests consist of tensile, bending and hard test. The results showed that the quality of a good TIG root weld at 70A, the highest tensile strength of the weld joint 52.27 kgf/mm2 (70A), the highest hardnest 164,217 HRB (90A), the bending strength 1.123,061 N/mm2 (70A) using face bend method and 1,172,959 N/mm2 with root bend. In SMAW root welding, the highest tensile strength 54.27 kgf/mm2 (70 A) , the highest hardnest  158.717 HRB (70 A), the highest bending strength 1.115,611 N/mm2 (70 A) using face bend method, and 1.161,748 N/ mm2 with root bend. 

scholarly journals MAG Welding of Structures Used in Means of Transport and Made of Steel DOCOL 1200M

2020 ◽  
pp. 65-71
Author(s):  
Bożena Szczucka-Lasota ◽  
Tomasz Węgrzyn ◽  
Bogusław Łazarz ◽  
Adam Jurek ◽  
Krzysztof Ireneusz Wilczyński
Keyword(s):  
Mechanical Properties ◽  
Tensile Strength ◽  
Research Work ◽  
Welding Parameters ◽  
Shielding Gases ◽  
High Tensile Strength ◽  
Moving Platform ◽  
Interpass Temperature ◽  
Made In

Steels of the DOCOL group, characterised by high tensile strength and yield point, play an important role in the manufacturing of means of transport. However, the above-named steels are difficult to weld and joints made in them do not guarantee comparable mechanical properties. The research work discussed in the article aimed to determine process parameters suitable for the welding of a moving platform made of steel DOCOL 1200M as well as to assess the effect of welding parameters on the quality of obtained joints. The tests also involved analysing the effect of shielding gases, preheating and interpass temperature on the quality of an 8 mm thick MAG welded moving platform structure.

Strength Quality Research of Cement Mortar Blended with Solar PV Cells

2014 ◽  
Vol 1025-1026 ◽  
pp. 1025-1030 ◽  
Author(s):  
Li Wei Teng ◽  
Ran Huang ◽  
Hui Mi Hsu ◽  
An Cheng ◽  
Jia Ruey Chang ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Solar Cells ◽  
Cement Paste ◽  
Cement Mortar ◽  
Solar Pv ◽  
Quality Research ◽  
Factors Affecting ◽  
Study Results ◽  
Made In

In this article we demonstrated the study results of strength quality of cement paste blended with waste solar PV cells. The conclusions were made on effect of this cement replacement. The use of ground solar cells on the mechanical properties of cement-based composite was investigated, and as a result, we identified the factors affecting the strength for those of cement mortar specimens which predefined and made in lab.

Mechanical Properties of Pure Carbon and Carbonnitrogen Coatings on Thin Film Head Sliders

1996 ◽  
Vol 436 ◽  
Author(s):  
G. Wang ◽  
A. Strojny ◽  
J. M. Sivertsen ◽  
J. H. Judy ◽  
W. W. Gerberich
Keyword(s):  
Thin Film ◽  
Mechanical Properties ◽  
Elastic Modulus ◽  
Carbon Films ◽  
Wear Protection ◽  
Pure Carbon ◽  
Wear Damage ◽  
Afm Micrographs ◽  
Better Than ◽  
Made In

AbstractThe mechanical properties of pure carbon (C) and carbon-nitrogen (C:N) coatings on thin film head sliders were investigated by continuous drag testing (CDT) and nano-indentation. Comparisons were made in terms of wear protection, elastic modulus and hardness of these two types of carbon films. The C and C:N thin films with various thickness were deposited on thin film head sliders using a facing target sputtering (FTS) system. After 23,000 revolutions of CDT tests, all the testing head sliders which were uncoated and coated with 90 Å C or C:N exhibited some degree of wear damage as indicated in AFM micrographs where that of the uncoated head was the most severe and that of the C:N coated head was the least. Head sliders coated with 1000Å C and C:N were studied under the TriboscopeTM nano-indenter, where load-displacement curves at different maximum loads were recorded. Elastic modulus and hardness were determined from those curves. The results show that elastic modulus and hardness of C:N are greater than that of C. Therefore, one may conclude that both C and C:N behave like a protective coating for the head slider where C:N is better than C, which could be well related to the larger elastic modulus and hardness of C:N.

Effect of Process Parameters on Seam Weld Quality of ZM21 Tubes

2012 ◽  
Vol 504-506 ◽  
pp. 487-492 ◽  
Author(s):  
Antonio Segatori ◽  
Barbara Reggiani ◽  
Lorenzo Donati ◽  
Tommaso Pinter ◽  
Y. Rami ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Magnesium Alloys ◽  
Process Condition ◽  
Process Conditions ◽  
Low Density ◽  
Transportation Industry ◽  
Testing Method ◽  
Porthole Die ◽  
Made In

The increasing attention to magnesium alloys in extruded profiles, especially in the transportation industry, is related to their low density associated with good mechanical properties and complete recyclability. This allows to push towards both increasing efficiency and pollution restrictions. However, these advantages are negatively balanced by the production rates drop in relation to dangerous profile temperatures increasing that force to keep low velocities. In this context, a novel porthole die has been purposely designed for magnesium alloys allowing an increasing of the process velocity up to four times with respect to past solutions. The mandrel consisted of three ports made by 120° bridges that created an equal number of seam welds. The extruded tubes, made in ZM21, were 50 mm in diameter and 2 mm in thickness and were tested under different process conditions. In the present work, the quality of the seam welds has been investigated in relation to each process condition by means of the rubber plug testing method that allowed to applied an hydrostatic tensile state.

Microstructure – Mechanical Properties Relationship of Laser Interference Irradiated Ni/Al Multi-Film

2003 ◽  
Vol 795 ◽  
Author(s):  
C. Daniel ◽  
A. Lasagni ◽  
F. Mücklich
Keyword(s):  
Thin Film ◽  
Mechanical Properties ◽  
Intermetallic Compounds ◽  
Physical Vapor Deposition ◽  
Thermal Simulation ◽  
Laser Interference ◽  
Structural Investigations ◽  
Relationship Of ◽  
Layered Thin Film ◽  
Made In

ABSTRACTDue to the corresponding intermetallic compounds, Ni/Al multi-layered thin film systems are important to protect against the mechanical and chemical impacts on the bulk component. The mechanical properties of these intermetallic compounds, NiAl, can be further improved by combining with other stiff phases. The mechanical properties would be optimized if the lateral surface composite can be made in such a way that the different phases are arranged periodically with a preferred orientation, micro-scaled period and reticulated phase interfaces. Such optimized surface composites have been achieved by laser interference irradiation in a nano-grained structure.In this study, the thin film systems are produced by physical vapor deposition and subsequently irradiated by the interference pattern of two or more coherent laser beams. The corresponding periodical heat treatment has been analyzed by thermal simulation, and thermal simulation results are compared with the experimental results. Further, the phase transitions during laser interference irradiation are calculated. The structural investigations of irradiated films - grain sizes and deformation by TEM, stress and texture by XRD - are compared with the mechanical properties - hardness and Young's modulus by NI-AFM.

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