The Dynamic Compaction of Metallic Powders

1983 ◽  
Vol 28 ◽  
Author(s):  
David G. Morris
Keyword(s):  
Shock Wave ◽  
High Temperature ◽  
Plastic Flow ◽  
Large Scale ◽  
High Pressures ◽  
Dynamic Compaction ◽  
Process Window ◽  
Hard Materials ◽  
Deformation Parameters ◽  
Interparticle Bonding

ABSTRACTThe Dynamic Compaction of powdered materials becomes a particularly attractive technique for consolidating hard materials, because of the ease with which high pressures are achieved, and for metastable materials, because of the possibility of avoiding large-scale, high temperature excursions. The shock-wave conditions necessary for achieving high densities and interparticle bonding are evaluated experimentally. The bonding and melting taking place can be identified by post-consolidation studies, and the inter-relation between compact integrity and melting is shown. An attempt is made to develop a “process window” analogous to that of explosive bonding, to describe the conditions necessary for consolidation. Finally, in view of the necessity for localisation of plastic flow during consolidation, an indication of the influence of material deformation parameters is given.

The Seizure of Metals

1949 ◽  
Vol 160 (1) ◽  
pp. 380-383 ◽  
Author(s):  
F. P. Bowden ◽  
D. Tabor
Keyword(s):  
Plastic Flow ◽  
Large Scale ◽  
High Pressures ◽  
Surface Films ◽  
Cold Welding ◽  
General Increase ◽  
Intimate Contact ◽  
Real Contact ◽  
Static Conditions ◽  
Heavy Damage

When metal surfaces are placed together, the area over which they touch is usually very small. As a result, the localized pressures at the points of real contact are sufficiently high to produce plastic flow of the metal. Even under static conditions, these high pressures may produce “cold-welding” between the surfaces, and the metallic junctions so formed may be very strong. These junctions are sheared during sliding, and if they are stronger than the parent metals, heavy damage may result which is not limited to the interface at which intimate contact occurs. The growth and extension of this localized damage constitutes seizure. It follows that those factors which facilitate localized welding will, in general, increase the chances of large-scale seizure. Similarly, surface films which are capable of reducing localized adhesion will reduce the chances of seizure.

The Potential of Photoelectrochemical Carbon Sinks

2018 ◽  
Author(s):  
Matthias May ◽  
Kira Rehfeld
Keyword(s):  
Global Warming ◽  
High Temperature ◽  
Greenhouse Gas ◽  
Large Scale ◽  
High Efficiency ◽  
Carbon Sink ◽  
Solar Fuels ◽  
Negative Emissions ◽  
Viable Approach ◽  
Low Sensitivity

Greenhouse gas emissions must be cut to limit global warming to 1.5-2C above preindustrial levels. Yet the rate of decarbonisation is currently too low to achieve this. Policy-relevant scenarios therefore rely on the permanent removal of CO<sub>2</sub> from the atmosphere. However, none of the envisaged technologies has demonstrated scalability to the decarbonization targets for the year 2050. In this analysis, we show that artificial photosynthesis for CO<sub>2</sub> reduction may deliver an efficient large-scale carbon sink. This technology is mainly developed towards solar fuels and its potential for negative emissions has been largely overlooked. With high efficiency and low sensitivity to high temperature and illumination conditions, it could, if developed towards a mature technology, present a viable approach to fill the gap in the negative emissions budget.<br>

The Potential of Photoelectrochemical Carbon Sinks

2018 ◽  
Author(s):  
Matthias May ◽  
Kira Rehfeld
Keyword(s):  
Global Warming ◽  
High Temperature ◽  
Greenhouse Gas ◽  
Large Scale ◽  
High Efficiency ◽  
Carbon Sink ◽  
Solar Fuels ◽  
Negative Emissions ◽  
Viable Approach ◽  
Low Sensitivity

Greenhouse gas emissions must be cut to limit global warming to 1.5-2C above preindustrial levels. Yet the rate of decarbonisation is currently too low to achieve this. Policy-relevant scenarios therefore rely on the permanent removal of CO<sub>2</sub> from the atmosphere. However, none of the envisaged technologies has demonstrated scalability to the decarbonization targets for the year 2050. In this analysis, we show that artificial photosynthesis for CO<sub>2</sub> reduction may deliver an efficient large-scale carbon sink. This technology is mainly developed towards solar fuels and its potential for negative emissions has been largely overlooked. With high efficiency and low sensitivity to high temperature and illumination conditions, it could, if developed towards a mature technology, present a viable approach to fill the gap in the negative emissions budget.<br>

DMV 25.7 N

Alloy Digest ◽  
2000 ◽  
Vol 49 (5) ◽  
Keyword(s):  
Mechanical Properties ◽  
Corrosion Resistance ◽  
High Temperature ◽  
Physical Properties ◽  
Tensile Properties ◽  
High Pressures ◽  
Heat Treating ◽  
Temperature Performance ◽  
Superior Corrosion Resistance

Abstract DMV 25.7 N is a superferritic-austenitic grade with high mechanical properties and superior corrosion resistance to chlorides, freshwater, and high pressures. This datasheet provides information on composition, physical properties, hardness, elasticity, and tensile properties. It also includes information on high temperature performance and corrosion resistance as well as forming, heat treating, machining, and joining. Filing Code: SS-785. Producer or source: DMV Stainless USA Inc.

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