Improving Global Quality of Life
Improving Global Quality of Life
Improving Global Quality of Life
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9 Needs and challenges <strong>of</strong> major industry sectors for future applications<br />
nano effects is not new in technology (e.g. in the glass industry), but has generally never been known by this<br />
name.<br />
While developments in nanotechnology can be utilised in joining technology, joining technology itself on the<br />
other hand is an essential step in manufacturing and assembly <strong>of</strong> nanodevices and nanosystems, to provide<br />
mechanical support and integration, electrical connection, optical coupling, environmental protection, etc.<br />
just like welding and joining at macro- and microscales. At the moment, there are two fields that are on the<br />
forefront:<br />
The utilization <strong>of</strong> nano effects for joining technology, such as the application <strong>of</strong> nanomaterials in<br />
joining technology.<br />
Joining <strong>of</strong> nanomaterials, or nano-scale building blocks, for applications in nanodevices and<br />
nanosystems.<br />
9.17.1 Nanotechnology for joining<br />
One example in this field is nanoparticle-alloyed filler metals for welding that can lead to nano-structurised<br />
solidification <strong>of</strong> the weld pool and hence to a structure with the same base metal properties. This can be<br />
combined with no or low heat input welding processes as well for the joining <strong>of</strong> nano alloyed materials,<br />
e.g. nanoalloyed steels for conventional use. Additionally the expected energy saving can be a sustainability<br />
aspect.<br />
Similarly, nanoparticle-based pastes are suited as a filler material, with the right composition, for joining<br />
with low heat input, in particular <strong>of</strong> electronic components, e.g. to replace lead-free solders. Up to now, the<br />
nanoparticles in the pastes, as a rule, are wrapped up in organic substances. When submitted to temperature,<br />
these organic coatings evaporate and thus the nanoparticles are released. Under low pressure, they bond,<br />
via a sintering-like process, with each other and with the material surfaces to be joined, in a firmly bonded<br />
manner by diffusion. The current developments go in the direction <strong>of</strong> substituting the organic coating<br />
substances with others in order to avoid the bothersome vaporization products and to further reduce the<br />
joining temperatures as well as to reduce the required pressure.<br />
Another option for the use <strong>of</strong> nano effects for joining is the use <strong>of</strong> Nan<strong>of</strong>oils®. These multi-layer bands, made<br />
up <strong>of</strong> layers that are 25 to 90 nm thick and comprise different materials, when laid between the surfaces to<br />
be joined, lead to a self-progressing exothermic reaction after ignition as a result <strong>of</strong> their negative binding<br />
energy. The heat required for welding is thereby generated directly in the joining zone. The very costly<br />
production <strong>of</strong> the tapes is disadvantageous.<br />
Nanoparticle-based adhesives with good adhesion, and electrical and other properties are also being<br />
developed and are used in the field <strong>of</strong> microelectronics.<br />
9.17.2 Joining <strong>of</strong> nanomaterials<br />
Nanomaterials are materials comprising nanoparticles (nanotubes, nan<strong>of</strong>oams, nan<strong>of</strong>ibers, nanowire)<br />
which are made <strong>of</strong> equivalent or different materials <strong>of</strong> the same kind and have the respective properties.<br />
The technical use <strong>of</strong> such materials requires bonding them with each other and with other materials to be<br />
assembled into nanodevices and nanosystems.<br />
In doing so, <strong>of</strong> course, the special properties <strong>of</strong> the nanomaterials are meant to be preserved as much as<br />
possible. Respective technologies and processes are currently being developed. For example, femto-second<br />
lasers are high performance pulse lasers with pulse durations in the femtosecond area (1 femtosecond =<br />
10 -15 seconds). By the use <strong>of</strong> such extremely short-pulsed lasers, new options arise for material machining<br />
Through Optimum Use and Innovation <strong>of</strong> Welding and Joining Technologies<br />
<strong>Improving</strong> <strong>Global</strong> <strong>Quality</strong> <strong>of</strong> <strong>Life</strong><br />
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