ICALEO 2005 Paper #1305 (Thermo-Mechanical Modeling of Hybrid Welding)

Thermo-Mechanical Modeling of Hybrid Welding
Authors:
Edward Reutzel, Applied Research Laboratory, Pennsylvania State University; State College PA USA
Michael Bugarewicz, Dept. of Nuclear and Mechanical Engineering, Pennsylvania State University; University Park PA USA
Panagiotis Michaleris, Dept. of Nuclear and Mechanical Engineering, Pennsylvania State University; University Park PA USA
Shawn Kelly, Applied Research Laboratory, Pennsylvania State University; State College PA USA
Richard Martukanitz, Applied Research Laboratory, Pennsylvania State University; State College PA USA
Presented at ICALEO 2005

A thermo-mechanical model for predicti...

ICALEO 2005 Paper #1304 (Development of an Empirical Model for Laser Forming of Austenitic Stainless Steels)

Development of an Empirical Model for Laser Forming of Austenitic Stainless Steels
Authors:
Jack Pennuto, University of Missouri-Rolla; Rolla MO USA
Joohyun Choi, University of Missouri-Rolla; Rolla MO United States
Presented at ICALEO 2005

Over the past two decades several empirical models have been developed in an effort to predict the laser forming bend angle for various situations of substrate material and laser media. The efforts have mainly focused on the area of single angle forming as well as the range within which there exists a relatively linear relationship between line energy and output bend angle. Most of these previous empirical models were developed for a single mat...

ICALEO 2005 Paper #1303 (Mathematical Model Based on Kinetics and Thermodynamics for Estimating the Properties of Laser Hardened Steel Surfaces)

Mathematical Model Based on Kinetics and Thermodynamics for Estimating the Properties of Laser Hardened Steel Surfaces
Authors:
Henrikki Pantsar, VTT Industrial Systems; Lappeenranta FI Finland
Presented at ICALEO 2005

High power laser beam is scanned over a surface of a component in laser transformation hardening. The absorbed energy of the laser beam heats the surface rapidly to temperatures near the melting point. A high cooling rate is achieved by self-quenching and a hard martensitic surface is formed. Due to the rapid thermal cycle, the phase transformations occur far from equilibrium and the estimation of the resulting hardness is problematic.

In the present study a mathematical mode...

ICALEO 2005 Paper #1302 (Modeling of Laser Keyhole Welding with Adaptive Mesh Refinement)

Modeling of Laser Keyhole Welding with Adaptive Mesh Refinement
Authors:
Peng Li, GE Global Research Center (Shanghai); Shanghai Peoples Republic of China
Hyungson Ki, Michigan State University; Lansing MI USA
Jyoti Mazumder, University of Michigan; Ann Arbor MI USA
Presented at ICALEO 2005

Adaptive mesh refinement (AMR) technique has been applied in the 3D numerical model for laser keyhole-welding simulation. SIMPLEC algorithm is realized with AMR in the program and level set method is adopted to capture the movement of the liquid/vapor interface. Knudsen layer, existed at the liquid/vapor interface, has been dealt as boundaries in the program using jump conditions....

ICALEO 2005 Paper #1301 (Microstructure, Modeling and Measurements of Thermal History)

Microstructure, Modeling and Measurements of Thermal History
Authors:
Xinhua Wu, The University of Birmingham; Birmingham UK
Junfa Mei, The University of Birmingham; Birmingham UK
Laura Qian, The University of Birmingham; Birmingham UK
Presented at ICALEO 2005

A 2D axis-symmetric-transient finite element model for direct laser fabrication has been developed for predicting the temperature history of Direct Laser Fabricated (DLFed) Ti-6Al-4V thin wall samples. The effect of location, laser scanning speed and laser power on the variation of temperature with time have been modelled and compared with temperatures measured using thermocouples during laser fabrication. The mi...

ICALEO 2005 Paper #1208 (Development of the Laser Stir Welding Process for Aluminum Laser Beam Welding)

Development of the Laser Stir Welding Process for Aluminum Laser Beam Welding
Authors:
Richard Martukanitz, Penn State University/ARL; State College PA USA
C. J. Warren, Alcoa Technical Center; Alcoa Center PA USA
I. Stol, Alcoa Technical Center; Alcoa Center PA USA
Jay Tressler, Applied Research Laboratory, Pennsylvania State University; State College PA USA
Presented at ICALEO 2005

Laser stir welding involves the manipulation of the laser beam to provide hydrodynamic stirring and subsequent healing of the keyhole. Since aluminum alloys tend to be especially sensitive to keyhole stability, the process was conceived for laser beam welding of these alloys....

ICALEO 2005 Paper #1207 (Active Stressing and the Control of Macro-Scale Damage in Unsupported Ceramics During Laser Machining)

Active Stressing and the Control of Macro-Scale Damage in Unsupported Ceramics During Laser Machining
Authors:
Albert Segall, The Penn State Univ.; University Park PA USA
Guodong Cai, Penn State; University Park PA USA
Paul Brugan, Penn State; University Park PA USA
Ravindra Akarapu, Penn State; University Park PA USA
Stephanie Pullford, The Penn State Univ.; University Park PA USA
Presented at ICALEO 2005

The low-force signature of lasers makes them very attractive for the machining of ceramics. Unfortunately, unwanted damage ranging from micro-cracks to macro-scale fracture including chips and burrs still plagues the practice, especially du...

ICALEO 2005 Paper #1206 (Cost Effective Laser Shock Processing Development at GE Aircraft Engines)

Cost Effective Laser Shock Processing Development at GE Aircraft Engines
Authors:
Todd Rockstroh, GE Transportation; Evendale OH USA
Presented at ICALEO 2005

GE Aircraft Engines (GEAE) has worked with various vendors since 1992 to develop laser shock processing. GEAE launched production on the stage one fan blades for the F101 / B1 Bomber and F110/F16 Falcon engines in 1996 and has, with the US Air Force, nearly completely retrofitted the USAF fleet. Intial applications were driven by critical performance and flight safety issues. The laser equipment was expensive to procure and maintain and required a highly skilled maintenance staff for daily setup and process maintenance. GEAE launched a ...

ICALEO 2005 Paper #1205 (Laser Drilling of Natural Granite Plates)

Laser Drilling of Natural Granite Plates
Authors:
Ramoto, Universidad de Vigo; Vigo Pontevedra Spain
Antonio Riveiro, University of Vigo; Vigo Spain
Mohamed Boutinguiza, Universidad de Vigo; Vigo Pontevedra Spain
Fx Quintero, Universidad de Vigo; Vigo Pontevedra Spain
Fernando Lusqui Universidad de Vigo; Vigo Pontevedra Spain
Juan Pou, Universidad de Vigo; Vigo Spain
Mariano Pz-Amor, Universidad de Vigo; Vigo Pontevedra Spain
Presented at ICALEO 2005

Following previous work focused on the laser processing of natural stones, we present in this paper the results of the study carried out to verify the feasi...

ICALEO 2005 Paper #1204 (CO2 Laser Welding Fused Silica)

CO2 Laser Welding Fused Silica
Authors:
Danny MacCallum, Sandia National Laboratories; Albuquerque NM USA
Gerald Knorovsky, Sandia National Laboratories; Albuquerque NM USA
Presented at ICALEO 2005

The feasibility of laser welding of fused silica (aka quartz) has been demonstrated recently by others. An application requiring hermetic sealing of a thin, pressure-bearing quartz diaphragm to a thicker frame led us to explore this technique. We found that laser welding techniques normally used for metallic parts caused scorching and uneven melting. Contrary to ?standard? practices (near focus, high travel speed, high power density), successful welds in fused silica required a broad ...