Selective Laser Sintering Melting Research Articles

Моделирование теплопроводности порошковой среды применительно к задаче селективного лазерного плавления

The speed and the cost of implementation of new techniques are directly dependent on the efficiency of each of the technological chain at all stages, from design and product design to create of its original mockup in full value. Dramatically accelerate the passage of these steps help to high-tech methods of 3-D computer modeling and the creation of hard copies of machine parts. Currently all over the world carry out intensive scientific research and experimental structure work not only on the creation of new, but also on the improvement technology previously deve­loped of methods and layered systems of laser synthesis of volume products (LSOI) machine parts. Methods of selective laser sintering(SLS), melting (SLM) and a three-dimensional laser melting (the DMD) is one of the most promising ways to implement rapid prototyping techno­logy[1]. There fore, the study of this topic at this point is urgent. Currently in many industries, are large heat flows from one surface to another, whereby even slight contact resistance causes local overheating, which is often highly undesirable. In this work was to study the effectiveness the thermal conductivity of granular systems, which was seen as a function of porosity, thermal conductivity, filling the pores of the material, the thermal conductivity of the gas microgap, the thermal conductivity of the particles themselves and contact the thermal conductivity at the junction of the particles. For theoretical studies of selective laser sintering it is necessary to develop methods to describe the effective thermal conductivity (EKT) powder medium, which take into account, that heating the partial or complete melting of the material areas may occur, resulting in a change in the structure of the medium. This implies an important requirement for EKT model: structural model in the limit of the total melting particulate material should give a value of the effective thermal conductivity, which is cross-linked with an effective thermal conductivity given by non-structured model. For the case of complete melting particles melt method is proposed for calculating the effective thermal conductivity gas as described in work.

Studies on Absorptivity and Marangoni Flow during Laser Sintering

Selective laser sintering (SLS) / melting (SLM) is a manufacturing technique which holds a very special place in the layer manufacturing process due to its widest range of material processing capability which no other technique can offer. It can process metals, rubber, composites, polymers and ceramics etc. As laser sintering technique is emerging as an advanced manufacturing technique, it is importance to study the phenomenon which affect the fabrication process, hence a study is undertaken to simulate the physical phenomenon such as laser absorption and Marangoni effect. By studying these phenomena, a much better control of the physical processes is possible during the laser sintering process of commercially pure titanium grade 2.

Porous biocompatible implants and tissue scaffolds synthesized by selective laser sintering from Ti and NiTi

An investigation of the technical aspects of producing sufficiently high strength porous biocompatible medical implants and tissue scaffolds from nitinol or pure titanium using selective laser sintering/ melting (SLS/M) is presented. In particular, the necessary processing parameters and procedures for successful laser synthesis of functionally graded implants have been established. Physical and mechanical properties, microstructure, corrosion behavior of the synthesized structures, as well as shape memory in porous layered nitinol structures made using laser synthesis are reported. Comparative morphological and histological results of SLS of porous titanium and nitinol made implants are also presented. Investigations were carried out on primary cultures of dermal fibroblasts and mesenchymal stromal human cells. The possibility of cultivating bone marrow on the porous carrier-incubator made from NiTi and pure titanium in vitro was determined. Sufficient understanding of the nature of laser synthesized titanium and nitinol structures was developed in order to determine their suitability for use as functional implants. This resulted in superior tissue to implant fixation and the development of minimally invasive surgical procedures.