Use Of Laser Equipment Research Articles

Investigation of structural-phase transformations of weld metal and in the heat-affected zone during laser welding

The use of laser equipment is one of the promising ways to create innovative and highly efficient technologies in the production of ship structures. The main advantages of using laser technologies in the production of marine equipment are increased productivity by increasing the speed and reducing the number of welding passes, improving the quality of welded joints due to the accuracy of the assembly of structures and the level of automation, reducing the level of residual stresses, warping and leash due to significant localization of the heating and penetration zone compared with arc welding technologies, a significant reduction in the consumption of welding materials or their complete exclusion due to the smaller dimensions of the geometry of the cutting edges and the width of the assembly gaps. The mechanical properties of the welded joint are determined by the composition of the steel and its structure. The structural- phase transformations of the weld metal are determined by the temperature-time parameters that occur in the seam zone itself and in the heat-affected zone. Laser welded joints are formed under conditions in which thermal cycles differ significantly in depth and width of the weld, so the mechanical properties of the joint are determined by local changes in the structure of the seam metal and heat-affected zone. The issues of formation of the phase composition of the seam zone and heat-affected zone during laser welding are examined in the paper. On the basis of numerical modeling of thermal processes and structural- phase transformations of weld metal and heat-affected zone accompanying laser welding, a method for quantifying the volume fraction of structural- phase components of weld metal and heat-affected zone is proposed. The proposed calculation algorithm avoids solving the equation for the amount of the volume fraction of the structural- phase components of the metal at each step of the calculations.

Processing composite materials with lasers

Composite materials, consisting of fibers and binders of natural and artificial origin, are increasingly used in various fields of industry. Processing of the obtained materials into finished forms is often difficult and expensive. Treatment of composite materials, such as milling, cutting, or grinding, is currently dominant.At present, lasers are increasingly used in production processes. It should be noted that modern industrial production is unthinkable without the use of laser equipment. However, when using lasers, initial adjustment of their laser parameters is required for optimal material processing. When considering different lasers and materials to be processed, the setting parameters are different and the obtained processing quality is varied.In the research, samples of composite materials have been made, consisting of epoxy resin as a binder and hemp, flax, and carbon fibers as reinforcing materials. The obtained composite materials have been studied with fiber laser for their processing quality.

Quantification of visits of wild fauna to a commercial free-range layer farm in the Netherlands located in an avian influenza hot-spot area assessed by video-camera monitoring.

Free‐range poultry farms have a high risk of introduction of avian influenza viruses (AIV), and it is presumed that wild (water) birds are the source of introduction. There is very scarce quantitative data on wild fauna visiting free‐range poultry farms. We quantified visits of wild fauna to a free‐range area of a layer farm, situated in an AIV hot‐spot area, assessed by video‐camera monitoring. A total of 5,016 hr (209 days) of video recordings, covering all 12 months of a year, were analysed. A total of 16 families of wild birds and five families of mammals visited the free‐range area of the layer farm. Wild birds, except for the dabbling ducks, visited the free‐range area almost exclusively in the period between sunrise and the moment the chickens entered the free‐range area. Known carriers of AIV visited the outdoor facility regularly: species of gulls almost daily in the period January–August; dabbling ducks only in the night in the period November–May, with a distinct peak in the period December–February. Only a small fraction of visits of wild fauna had overlap with the presence of chickens at the same time in the free‐range area. No direct contact between chickens and wild birds was observed. It is hypothesized that AIV transmission to poultry on free‐range poultry farms will predominantly take place via indirect contact: taking up AIV by chickens via wild‐bird‐faeces‐contaminated water or soil in the free‐range area. The free‐range poultry farmer has several possibilities to potentially lower the attractiveness of the free‐range area for wild (bird) fauna: daily inspection of the free‐range area and removal of carcasses and eggs; prevention of forming of water pools in the free‐range facility. Furthermore, there are ways to scare‐off wild birds, for example use of laser equipment or trained dogs.

The Use of Laser Equipment to Optimize the Operating Parameters of the Fuel Injector of Combustion Engine

The Use of Laser Equipment to Optimize the Operating Parameters of the Fuel Injector of Combustion Engine

Acupuntura, láser y De Qi

Over the past decade, references to the use of laser equipment for the stimulation of acupuncture points have become increasingly common. A number of companies now offer laser equipments with a variety of characteristics, but it is often difficult to compare these and decide which is best for a given purpose. Thus, the objective of the present short review is to evaluate the published evidence for the real effectiveness of laser therapy. To this end, and taking into account classical tenets, it is essential to ascertain if this type of stimulus is capable of triggering acupunctural sensation or “De Qi”. Laser application for acupuncture has features in common with Low Level Laser Therapy. The 1-100 mW power range has been shown to be most effective. The wavelengths most frequently employed range from ultraviolet to infrared. Despite the fact that the penetrative power of red-infrared radiation is higher (due to its longer wavelength), encouraging results have also been reported with blue-violet light. In both these radiation ranges, the De Qi sensation has been reported to occur, but the qualitative characteristics and instauration times of both are different. We conclude that it is necessary to standardize technical parameters and carry out more basic and clinical research in this area, in order that the effects of laser stimulation can be as efficacious or even more effective than those obtained with classical acupuncture needles.

Basic directions of effective use of laser equipment for heat treatment of alloys

For the thirty six years that have passed since the creation of the first laser, laser engineering has progressed enormously. For example, for the last twenty years the world volume of sales of all kinds of lasers for civil purposes has increased more than tenfold in monetary terms, growing by 15% every year. In 1995, over 90 million lasers were sold for over 1.2 billion dollars. Today we know over 100 fields of laser application. The primary use of lasers is for treating materials; the volume of such sales has grown by an order of magnitude for the last twenty years and amounts to 350 million dollars a year (about 25% of the cost of all lasers), which is equal to 20 thousand units a year. The author of the present paper analyzes and gives examples of the use of lasers for heat treatment of tools and various machine parts.

Regulations Governing the Use of Laser Equipment

Anyone using a medical laser must contact the local Laser Protection Adviser, and is likely to have to register his premises as a Nursing Home.

Use of laser equipment to detect mechanical resonances and to stabilize vibration parameters at a specified value

Use of laser equipment to detect mechanical resonances and to stabilize vibration parameters at a specified value