scholarly journals Evaluation of Precipitates Type in Brasses as a Function of Charge Material

2016 ◽  
Vol 16 (3) ◽  
pp. 19-24
Author(s):  
A.W. Bydałek ◽  
K. Najman ◽  
A. Kula ◽  
S. Biernat ◽  
L. Błaż ◽  
...  

Abstract Trial series of cast alloy MO59 obtained from qualified scrap was investigated. SEM and TEM of resulting precipitates were conducted. The SEM analysis demonstrated the dependence of silicon, phosphorus, iron, chromium and nickel in the composition of the so-called hard precipitates. TEM analysis showed the formation of phase AlFeSi and AlCr. Made studies have shown the important role of the composition of the batch melts brass CuZn39Pb2 type. The analysis of SEM and TEM resulting precipitates pointed to the formation of various forms of divisions, only one of which was described in the literature character of the so-called hard inclusions. The SEM studies demonstrated the dependence of the occurrence of inclusions rich in silicon, phosphorus, iron, chromium and nickel. In contrast, additional TEM analysis indicated the formation of AlFeSi phase type and AlCr. The results of the analyses referred to the structure of the batch. Due to the difficulty of obtaining recycled materials that do not contain these elements necessary to carry out further analyzes in the direction of defining the role of phosphorus in the formation of the so-called hard inclusions.

1990 ◽  
Vol 199 ◽  
Author(s):  
J. P. Benedict ◽  
Ron Anderson ◽  
S. J. Klepeis ◽  
M. Chaker

ABSTRACTThe procedures described in this paper allow both SEM and TEM analysis to be performed on the same, device specific, semiconductor cross section. In order to accomplish this, a number of tools and fixtures have been constructed that allow the user to polish into the sample to a predetermined plane-of-polish, bisecting the device or feature of interest for SEM analysis. After SEM examination, the specimen is prepared for TEM analysis by first affixing a grid to the just-examined surface, inverting the specimen and parallel-polishing the backside of the specimen until the specimen's total thickness is in the 0.5 to 1.0μm range using the described tools. A subsequent one to ten minute ion milling step cleans the specimen. A very considerable positive side-effectof this method is the nearelimination of artifacts arisingfrom the use of strong chemicals and lengthy ion milling. The method has been extended to the preparation of plan-view device samples and non-semiconductor specimens.


Author(s):  
Stanley J. Klepeis ◽  
J.P. Benedict ◽  
R.M Anderson

The ability to prepare a cross-section of a specific semiconductor structure for both SEM and TEM analysis is vital in characterizing the smaller, more complex devices that are now being designed and manufactured. In the past, a unique sample was prepared for either SEM or TEM analysis of a structure. In choosing to do SEM, valuable and unique information was lost to TEM analysis. An alternative, the SEM examination of thinned TEM samples, was frequently made difficult by topographical artifacts introduced by mechanical polishing and lengthy ion-milling. Thus, the need to produce a TEM sample from a unique,cross-sectioned SEM sample has produced this sample preparation technique.The technique is divided into an SEM and a TEM sample preparation phase. The first four steps in the SEM phase: bulk reduction, cleaning, gluing and trimming produces a reinforced sample with the area of interest in the center of the sample. This sample is then mounted on a special SEM stud. The stud is inserted into an L-shaped holder and this holder is attached to the Klepeis polisher (see figs. 1 and 2). An SEM cross-section of the sample is then prepared by mechanically polishing the sample to the area of interest using the Klepeis polisher. The polished cross-section is cleaned and the SEM stud with the attached sample, is removed from the L-shaped holder. The stud is then inserted into the ion-miller and the sample is briefly milled (less than 2 minutes) on the polished side. The sample on the stud may then be carbon coated and placed in the SEM for analysis.


2018 ◽  
Author(s):  
Liangshan Chen ◽  
Yuting Wei ◽  
Tanya Schaeffer ◽  
Chongkhiam Oh

Abstract The paper reports the investigation on the root cause of source-drain leakage in bulk FinFET devices. While the failing device was readily isolated by nanoprobing technique and the electrical analysis pinpointed the potential defect location inside the Fin channel, the identification of physical root cause went through extreme challenges imposed by the tiny-sized device and the unique FinFET 3D architecture. The initial TEM analysis was misled by the projection of a species in the lamella surface and thus could not explain the electrical data. Careful analysis on the device structure was able to identify the origin of the species and led to the discovery of the actual root cause. This paper will provide the analysis details leading to the findings, and highlight the role of electrical understanding in not only providing guidance for physical analysis but also revealing the true root cause of failure in FinFET devices.


2021 ◽  
Vol 22 (1) ◽  
Author(s):  
Britta Kuehlmann ◽  
Isabel Zucal ◽  
Clark Andrew Bonham ◽  
Lydia-Marie Joubert ◽  
Lukas Prantl

Abstract Background Capsular fibrosis (CF) is the most common long-term complication in implant-based breast augmentation. It is well accepted that the foreign body response (FBR) instigates the development of fibrotic disease. Our study aims to compare murine and human samples of CF and describe the cellular and extracellular matrix (ECM) composition using scanning and transmission electron microscopy (SEM and TEM). Results Miniature microtextured silicone breast implants were implanted in mice and subsequently harvested at days 15, 30, and 90 post-operation. Isolated human capsules with the most aggravated form of CF (Baker IV) were harvested post-operation. Both were analyzed with SEM and TEM to assess cellular infiltration and ECM structure. An architectural shift of collagen fiber arrangement from unidirectional to multidirectional was observed at day 90 when compared to days 15 and 30. Fibrosis was observed with an increase of histiocytic infiltration. Moreover, bacterial accumulation was seen around silicone fragments. These findings were common in both murine and human capsules. Conclusions This murine model accurately recapitulates CF found in humans and can be utilized for future research on cellular invasion in capsular fibrosis. This descriptive study helps to gain a better understanding of cellular mechanisms involved in the FBR. Increases of ECM and cellularity were observed over time with SEM and TEM analysis.


2008 ◽  
Vol 8 (12) ◽  
pp. 6316-6324 ◽  
Author(s):  
M. Comes Franchini ◽  
P. Fabbri ◽  
A. Frache ◽  
G. Ori ◽  
M. Messori ◽  
...  

Two organophilic bentonites, based on nitrogen-containing compounds, have been synthesised via ion exchange starting from pristine bentonite with octadecyltrimethylammonium bromide (OTAB) and with synthetic melamine-derived N2,N4-dihexadecyl-1,3,5-triazine-2,4,6-triamine (DEDMEL). The chemical and morphological characterization of the organoclays was based on XRD, TEM, Laser Granulometry, X-Ray Fluorescence and CEC capacity. Copoly(styrene-butadiene-styrene)-nanocomposites (SBS-nanocomposites) were obtained by intercalation of the SBS-copolymer into these new organoclays by melt intercalation method. XRD and TEM analysis of the organoclays and of the micro/nano-composites obtained are presented. The effect of the organoclays on the SBS-nanocomposite's flammability properties was investigated using cone calorimeter. An encouraging decrease of 20% in the peak heat released rate (PHRR) has been obtained confirming the important role of melamine's based skeleton and its derived organoclays to act as effective fire retardants and for the improvement of this important functional property in SBS copolymers.


2011 ◽  
Vol 1 (2) ◽  
Author(s):  
Jerzy Smolik

AbstractThis article presents results which enabled the determination of the role of CrN coating and the influence of its thickness on the effectiveness of hybrid layer “nitrided layer / CrN coating” in the process of increasing the durability of forging dies. Dies coated with hybrid layers “nitrided layer / CrN coating” with various CrN coating thickness were — after different maintenance periods — subjected to metallographic testing, 3D shape testing and SEM analysis. Hardness distribution was also determined. The obtained results revealed that for all tested dies, independently from CrN coating thickness, the main mechanisms of their destruction was mechanical and thermal fatigue, and plastic deformation. It has been shown that the main role of CrN coating in the hybrid layer ”nitrided layer / PVD coating” is to counteract a high temperature influence the source of which is forging on die material. In order to do so the CrN coating should be characterized by a considerably lower thermal conductivity coefficient to steel and low hardness so that it can efficiently resist fatigue processes in the forging process. Based on testing conducted by means of the sin 2 φ method, it was revealed that internal stresses are vitally important for CrN coating for fatigue resistance of hybrid layer ”nitrided layer / CrN coating” during the forging process.


2019 ◽  
Vol 1 (3) ◽  
pp. 166-174
Author(s):  
Praja Hadi Saputra ◽  
Hamid Bone ◽  
Indah Permatasari

This study investigates the role of levers-of-control (LOC) based controlling system in the strategy formulation and MSME performance relationship in Samarinda. Through a survey conducted on the leadership (controller) of MSMEs in Samarinda City, this study evidenced the role of management control systems in the strategy formulation and MSME performance relationship. Of the 49 responses of MSME leaders, processed using PLS-SEM analysis, this study provided empirical evidence that the strategy formulation had a positive relationship with MSME performance. In addition, the indirect relationship between the two (mediation) through LOC-based management system supported the mediation hypothesis that the LOC-based management control system affects the strategy formulation and MSME performance relationship. In other words, it can be concluded that the management control system can increase the strategy formulation role that leads to MSME performance betterment.  


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