What is laser heating?
Laser heat treating is a surface modification process designed to change the microstructure of metals through controlled heating and cooling. An advantage that lasers offer in this process is the ability to heat treat localized areas without affecting the entire work piece.
What is a heat transfer model?
It consists of a heat transfer model of a building, which is subjected to a specified external climatic environment and an internal loading according to bulding usage and occupancy. From: Energy Developments: New Forms, Renewables, Conservation, 1984.
How does a laser transfer heat?
The irradiation of tissue by laser light results in the absorption of energy. Since this is a fully dissipative process, the consequence is that the increment in energy is expressed entirely as a heat transfer absorbed by the tissue.
What are the types of heat sources available for modeling?
These models are known as steady state moving point heat source, transient moving point heat source, semi-elliptical moving heat source, double elliptical moving heat source, and uniform moving heat source.
What are the merits of laser heating?
Laser radiation provides the most suitable choice for the purpose of heating the material during microforming process as it offers several advantages in comparison to other methods, including [35]: (1) the laser energy input and thus the resulting temperature in the workpiece can be easily controlled via the current of …
Is a laser light or heat?
Heat is the random motion of matterparticles (atomic or molecular particles) – however, the laser beam itself is not made of matter but of ‘photons’, the so-called ‘light particles’ which have no mass, i.e. that a laser beam can have no temperature.
What is heat source model?
The heat source model is a mathematical function which represents how much of a heat source’s power actually goes into heating the powdered metal and how this heat is distributed across the heat-affected zone (HAZ).
What is Gaussian heat source?
The Gaussian heat source is a model in which heat is generated over a surface; therefore, it may not be suitable to be applied to thick plates. In this study, the accuracy of the Gaussian heat source model is investigated in bead-on-plate welding by the TIG process.
How is the incident heat flux from the laser modeled?
The incident heat flux from the laser is modeled as a spatially distributed heat source on the surface. The transient thermal response of the wafer is shown. The peak, average, and minimum temperature during the heating process is computed, as well as the temperature variations across the wafer.
What is the nature of laser heating?
The nature of laser heating is to change the internal microstructure of metal by the energy absorption. The metal absorptivity of laser light is a critical factor that influences the deformation process, and the copper absorptivity of laser light is almost independent on temperature [2].
What factors affect the efficiency of laser heat conversion?
The efficiency with which a material absorbs an incoming laser beam and converts it to heat depends on the properties of materials and operating conditions as well as on the types and characteristics of the beam, such as wavelength, divergence of the incoming beam, and spatial intensity profile.
How does a laser heat up a silicon wafer?
A silicon wafer is heated up by a laser that moves radially in and out over time. In addition, the wafer itself is rotated on its stage. The incident heat flux from the laser is modeled as a spatially distributed heat source on the surface. The transient thermal response of the wafer is shown.