Descripción
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Laser shock processing (LSP) or laser shock peening is a new technique for strengthening metals. This process induces a compressive residual stress field which increases fatigue crack initiation life and reduces fatigue crack growth rate. Specimens of 6061-T6 aluminum alloy and AISI 304 stainless steel are used in this investigation. A convergent lens is used to deliver 1.2J, 9ns laser pulses by a Q-switched Nd:YAG laser, operating at 10Hz with infrared (1064 nm) radiation. The pulses are focused to a diameter of 1.5mm onto a water-immersed type samples. Effect of pulse density in the residual stress field is evaluated. Residual stress distribution as a function of depth is determined by the hole drilling method. It is observed that the higher the pulse density the larger the zone size with compressive residual stress. Densities of 900, 1350 and 2500 pulses/cm2 are used for the aluminum case; and 2500 and 5000 pulses/cm2 for the steel case. Pre-cracked compact tension specimens were subjected to LSP process and then tested under cyclic loading with R=0.1. Fatigue crack growth rate is determined and the effect of LSP process parameters is evaluated. Fatigue crack growth rate is compared in specimens with and without LSP process. In addition fracture toughness is determined in specimens with and without LSP treatment. It is observed that LSP reduces fatigue crack growth and increases fracture toughness in both materials. | |
Internacional
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Si |
Nombre congreso
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First International Conference on Laser Peening |
Tipo de participación
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960 |
Lugar del congreso
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Johnson Space Center NASA, Houston, Texas (EE.UU.) |
Revisores
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Si |
ISBN o ISSN
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0000000000 |
DOI
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Fecha inicio congreso
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15/12/2008 |
Fecha fin congreso
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17/12/2008 |
Desde la página
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1 |
Hasta la página
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1 |
Título de las actas
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PRESENTACIONES EN LA PÁGINA WEB DEL CONGRESO |