Dr. Sabine Schreck Profile

Dr. Sabine Schreck

at Forschungszentrum Karlsruhe

SPIE Involvement:

Author

Publications (2)

This will count as one of your downloads.

You will have access to both the presentation and article (if available).

DOWNLOAD NOW

This content is available for download via your institution's subscription. To access this item, please sign in to your personal account.

Email or Username Forgot your username?

Password Forgot your password?

Show

Keep me signed in

No SPIE account? Create an account

Proceedings Article | 25 February 2009 Paper

Local modification of ceramic surfaces by a laser induced cladding process

Sabine Schreck, Magnus Rohde

Proceedings Volume 7202, 72020A (2009) https://doi.org/10.1117/12.810701

KEYWORDS: Ceramics, Laser processing, Resistance, Cladding, Particles, Temperature metrology, Copper, Composites, Nickel, Metals

Read Abstract +

In order to develop a multifunctional material, a laser induced process was applied to change the properties of a glass-ceramic by introducing a second phase into the surface. Localized melting of the ceramic and/or a melting of a preplaced powder layer was achieved by the application of laser energy. After solidification a composite with new properties was developed. The characteristic feature of the process is the option of a local modification, which is restricted to the substrate surface and can be controlled by adjustment of the laser parameters. Accordingly modified areas with different geometries and with a complex multiphase microstructure could be fabricated, while the ceramic bulk remains in its original state. Sintered LTCC-substrates (Low Temperature Co-fired Ceramic) were modified with powders metal-oxides (WO₃, CuO) with nanosized particles. Powders of metals (Cu, Ni) were used too. Cladding layers located at the top of the substrate or layers with a thickness up to several hundred microns, which were embedded into the substrate surface, could be fabricated. The properties of the laser modified regions differ significantly from that of the LTCC-substrate. The obtained structures offer modified mechanical, thermophysical and electrical properties. In particular an enhanced thermal conductivity could be detected. The electrical resistivity of the laser modified tracks widely varied depending on the process parameters and the powder. Tracks made with CuO- and WO₃-powders show a negative temperature coefficient for electrical resistance, i.e. it decreases with increasing temperature, which is typical for semiconductors.

Proceedings Article | 22 February 2008 Paper

Laser alloying and cladding of glass-ceramic surfaces using nano-scaled metal-oxide powders

Magnus Rohde, Sabine Schreck, Sophia Sachse

Proceedings Volume 6880, 688004 (2008) https://doi.org/10.1117/12.763076

KEYWORDS: Ceramics, Cladding, Resistance, Particles, Laser processing, Temperature metrology, Composites, Metals, Carbon dioxide lasers, Oxides

Read Abstract +

Laser supported processes can be used to modify the properties of ceramic substrates locally. These processes are characterised by a strong thermal interaction between the laser beam and the ceramic surface which leads to localised melting. During the dynamic melting process second phase particles are introduced into the melt pool in order to modify the physical properties. LTCC (Low Temperature Co-fired Ceramics)-substrates were laser alloyed and coated by laser cladding using nanoscaled powders of WO₃and CuO. Depending on the process parameters and the powders used modified areas with different geometries could be fabricated with a complex multiphase microstructure. Particle agglomerates, small crystals as well as grains covered with reaction phase could be found inside the microstructure, in parts with typical length scales in the submicron range. The properties of the laser modified tracks differ significantly from that of the substrate. In particular the thermal and electrical properties were changed. An enhanced thermal conductivity could be detected in laser tracks alloyed with the nano-scaled CuO- and WO₃-powders. The electrical resistivity showed a semiconducting behaviour with a negative temperature coefficient, i.e. it decreases with increasing temperature.

My Library

You currently do not have any folders to save your paper to! Create a new folder below.

Folder Name

Folder Description

View contact details

UPDATE YOUR PROFILE

Is this your profile? Update it now.

Sign into your SPIE.org account

Don’t have a profile and want one?

Create an account on SPIE.org

Access to the requested content is limited to institutions that have purchased or subscribe to SPIE eBooks. You are receiving this notice because your organization may not have SPIE eBooks access.*

*Shibboleth/Open Athens users─please sign in to access your institution's subscriptions.

To obtain this item, you may purchase the complete book in print or electronic format on SPIE.org.

ORGANIZATIONAL
Sign in with credentials provided by your organization.

Organizational Username

Organizational Password

Show/Hide Password

INSTITUTIONAL
Select your institution to access the SPIE Digital Library.

SELECT YOUR INSTITUTION

PERSONAL
Sign in with your SPIE account to access your personal subscriptions or to use specific features such as save to my library, sign up for alerts, save searches, etc.

PERSONAL SIGN IN

No SPIE Account? Create one

PURCHASE THIS CONTENT

SUBSCRIBE TO DIGITAL LIBRARY

50 downloads per 1-year subscription

Members: $195

Non-members: $335 ADD TO CART

25 downloads per 1 - year subscription

Members: $145

Non-members: $250 ADD TO CART

PURCHASE SINGLE ARTICLE

Includes PDF, HTML & Video, when available

Members:

Non-members: ADD TO CART

Keywords/Phrases

Search In:

Publication Years