scholarly journals RESEARCH OF THE MECHANISM OF COMPACTION OF MIXTURES OF POWDERS OF REFRACTORY CARBIDES WITH A METALLIC BOND IN EXPLOSIVE PRESSING ON A METAL SUBSTRATE

2021 ◽  
pp. 42-47
Author(s):  
A. V. Krokhalev ◽  
V. O. Kharlamov ◽  
D. R. Chernikov ◽  
E. A. Kosova ◽  
S. V. Kuzmin ◽  
...  
Keyword(s):  
Metal Substrate ◽  
Dynamic Flow ◽  
Refractory Carbide ◽  
Phase Component ◽  
Metal Binder ◽  
Metallic Bond ◽  
Carbide Component ◽  
Main Factor ◽  
Explosive Pressing

The results of investigations of the features of the behavior of the components of mixtures of refractory carbide powders with metals during explosive pressing are presented. It is shown that the main factor determining the compaction of mixtures is the dynamic flow of one of the phase components of the mixture into the initial pores of the powder. As the phase component of the mixture, the movement of which limits the degree of compaction and leads to the formation of a continuous matrix in the structure of the material pressed by the explosion, both the metal binder and the carbide component of the material can act.

Nonwetting Effects of Si Contamination on Cu Bumps of a Flip Chip Package—A Case Study

2016 ◽  
Author(s):  
Janella Mae R. Salamania
Keyword(s):  
Flip Chip ◽  
Metal Substrate ◽  
Molten Solder ◽  
Open Unit ◽  
Future Studies ◽  
Foreign Materials ◽  
Silicon Contamination ◽  
Substrate Sample ◽  
Main Factor

Abstract Presence of foreign materials (i.e, contamination) can affect the reliability of copper (Cu) bumps when it affects the wettability of the solder and consequently weakens the joint formation of the copper to the substrate. This paper looks at a case of non-wetting of Cu bumps due to silicon contamination induced during assembly processing. In this case study, surface roughness is the main factor being altered when foreign materials contaminate the metal substrate. Sample devices were tested in a resistive open unit and a direct current failing unit, respectively. It was found that the silicon dust present on the substrate in effect "roughens" the surface, thereby decreasing the wettability between the molten solder to the metal substrate. For future studies, it is recommended that the effect of reliability stress activities on the Cu bumps with silicon contaminations be examined to evaluate the risks for possible field failures of this defect.

scholarly journals RESEARCH OF THE MECHANISM OF SEALING POWDER MIXTURES BASED ON SILICON CARBIDE IN EXPLOSIVE PRESSING

2020 ◽  
pp. 20-24
Author(s):  
A. V. Krokhalev ◽  
V. O. Kharlamov ◽  
M. A. Tupitsyn ◽  
E. A. Kosova ◽  
S. V. Kuzmin ◽  
...  
Keyword(s):  
Shock Wave ◽  
Silicon Carbide ◽  
Explosive Loading ◽  
Binder Content ◽  
Powder Mixtures ◽  
Metal Binder ◽  
Wave Compression ◽  
Shock Wave Compression ◽  
Ti Powder ◽  
Explosive Pressing

The effects of the metal binder content and parameters of shock-wave compression on the compaction of SiC-Ti powder mixtures under explosive loading were investigated; microstructure of the obtained materials; The prevailing mechanisms of compaction of powder mixtures of silicon carbide with titanium during explosive pressing are revealed.

Existence of Cubic ZrO2 at 300°C on Bulk Zirconium

1969 ◽  
Vol 27 ◽  
pp. 166-167
Author(s):  
R.A. Ploc
Keyword(s):  
Metal Oxide ◽  
Metal Substrate ◽  
Preferred Orientation ◽  
Monoclinic Zirconia ◽  
Epitaxial Relationship

The manner in which ZrO2 forms on zirconium at 300°C in air has been discussed in the first reference. In short, monoclinic zirconia nucleates and grows with a preferred orientation relative to the metal substrate. The mode of growth is not well understood since an epitaxial relationship which gives minimum misfit between the zirconium ions in the metal/oxide combination is not realized. The reason may be associated with a thin cubic or tetragonal layer of ZrO2 between the inner oxygen saturated metal and the outer monoclinic zirconia.

Role of Transcriptional Read-Through in PRE Activity in Drosophila melanogaster

Acta Naturae ◽  
2016 ◽  
Vol 8 (2) ◽  
pp. 79-86 ◽  
Author(s):  
P. V. Elizar’ev ◽  
D. V. Lomaev ◽  
D. A. Chetverina ◽  
P. G. Georgiev ◽  
M. M. Erokhin
Keyword(s):  
Dna Sequences ◽  
Cell Types ◽  
Transcription Terminator ◽  
Response Elements ◽  
Polycomb Response Elements ◽  
The Individual ◽  
Multicellular Organisms ◽  
Different Cell Types ◽  
Main Factor

Maintenance of the individual patterns of gene expression in different cell types is required for the differentiation and development of multicellular organisms. Expression of many genes is controlled by Polycomb (PcG) and Trithorax (TrxG) group proteins that act through association with chromatin. PcG/TrxG are assembled on the DNA sequences termed PREs (Polycomb Response Elements), the activity of which can be modulated and switched from repression to activation. In this study, we analyzed the influence of transcriptional read-through on PRE activity switch mediated by the yeast activator GAL4. We show that a transcription terminator inserted between the promoter and PRE doesnt prevent switching of PRE activity from repression to activation. We demonstrate that, independently of PRE orientation, high levels of transcription fail to dislodge PcG/TrxG proteins from PRE in the absence of a terminator. Thus, transcription is not the main factor required for PRE activity switch.

Right to contestation, patron-client networks, and corruption

2012 ◽  
pp. 101-117 ◽  
Author(s):  
P. Orekhovsky
Keyword(s):  
Open Access ◽  
Political Life ◽  
Limited Access ◽  
The Right ◽  
Main Factor

In the paper the nature of Russian corruption is considered along the lines proposed by D. North, J. Wallis, and B. Weingast. The author considers patron-client networks as basic political and economic actors of the limited access order. The redistributive rent allocated within patron-client networks is not a corruption phenomenon. The main factor that is able to destroy patron-client networks and autonomous centers of power is the right to contestation (liberalization) according to R. Dahl. Realization of that right together with the right to participate in political life enables transition to the open access society.

Educational Programs as the Element of Managing Corporate Knowledge

2006 ◽  
pp. 129-139
Author(s):  
V. Golubkin ◽  
S. Kalendzhyan ◽  
L. Kleyeva
Keyword(s):  
Educational Programs ◽  
Knowledge Circulation ◽  
Innovation Processes ◽  
Main Factor

The modern approaches and mechanisms of managing the organization knowledge being now the main factor of innovation processes are observed in the article. Functioning of such mechanisms is not simple and needs outsourcers in education and consulting. In order to make the management effective the interaction of the company with the outsourcer should sustain the process of permanent knowledge circulation.

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