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This paper presents a unified framework to model the sintering process of fine powders. The framework is based on classical virtual power principle and its corresponding variational principle. Firstly, the classical models of solid state, viscous and liquid phase sintering are reproduced assuming single matter re‐distribution mechanism and using the virtual power principle as the starting point. Then we demonstrate how to obtain the governing equations for microstructural evolution using the variational principle. These provide a common thread through the existing sintering models. Finally a numerical solution scheme is briefly outlined for computer simulation of microstructural evolution using the variational principle as the starting point. The computer simulation can follow the entire sintering process from powder compact to fully dense solid and deal with fully couple multi‐physics processes involving all the possible underlying matter re‐distribution mechanisms. Several examples are provided to demonstrate the deep insights that can be gained into the sintering process by using the numerical tool.

A comparative characterisation of selective laser sintering (SLS) mechanisms of single‐ and two‐component powders is presented. The effects of the volume fraction of liquid phase and the powder absorptance were discussed. Single‐component Ni‐alloy, Fe and Cu powders as well as two‐component powder systems based on Ni‐alloy, Fe and Cu were investigated. In particular, the following types of two‐component powder systems were studied: Ni‐alloy‐Cu and Fe‐Cu powder mixtures as well as Cu‐coated Ni‐alloy powder and Cu‐coated Fe powders. SLS experiments were performed with a CW‐ Nd:YAG laser (λ=1.06 μm). The acting mechanism in all cases was liquid phase sintering.

Selective metal powder sintering is a layer‐by‐layer manufacturing system producing metallic parts with good mechanical properties. Describes why an Fe‐Cu powder mixture has been selected as the basic material for the process. Deals with the powder deposition issue and proposes a mechanism which can deposit thin powder layers on top of a recipient. Shows that the powder deposition mainly depends on the powder properties. States that the required powder properties are partially compatible with the specifications set by the technology of selective sintering but that some properties are in conflict with one another. Discusses the resulting compromises needed in the powder mixtures and the required modifications to the deposition mechanism.

Considers efforts to date to produce parts by direct selective laser sintering (SLS) of metals, including post processing to improve structural integrity and/or to induce a transformation. Provides a brief overview of the basic principles of SLS machine operation, and discusses materials issues affecting direct SLS of metals and the resultant properties and microstructures of the parts. Reviews results of past efforts on SLS of metal systems such as Cu‐Sn, Cu‐Solder (Pb‐Sn), Ni‐Sn, pre‐alloyed bronze (Cu‐Sn). Finally discusses more recent efforts on SLS of bronze‐nickel powder mixtures in greater detail.

This paper aims to provide a review on the process of additive manufacturing of ceramic materials, focusing on partial and full melting of ceramic powder by a high-energy laser beam without the use of binders.

Selective laser sintering or melting (SLS/SLM) techniques are first introduced, followed by analysis of results from silica (SiO₂), zirconia (ZrO₂) and ceramic-reinforced metal matrix composites processed by direct laser sintering and melting.

At the current state of technology, it is still a challenge to fabricate dense ceramic components directly using SLS/SLM. Critical challenges encountered during direct laser melting of ceramic will be discussed, including deposition of ceramic powder layer, interaction between laser and powder particles, dynamic melting and consolidation mechanism of the process and the presence of residual stresses in ceramics processed via SLS/SLM.

Despite the challenges, SLS/SLM still has the potential in fabrication of ceramics. Additional research is needed to understand and establish the optimal interaction between the laser beam and ceramic powder bed for full density part fabrication. Looking into the future, other melting-based techniques for ceramic and composites are presented, along with their potential applications.

This paper aims to find proper technological parameters of low-temperature joining technique by silver sintering to eventually use this technique for reliable electronic packaging.

Based on the literature and author’s own experience, the factors influencing the nanosized Ag particle sintering results were identified, and their significance was assessed.

It has been shown that some important technological parameters clearly influence the quality of the joints, and their choice is unambiguous, but the meaning of some parameters is dependent on other factors (interactions), and they should be selected experimentally.

The value of this research is that the importance of all technological factors was analyzed, which makes it easy to choose the technological procedures in the electronic packaging.

The particularities of the selective laser processing of single‐component metal powder layers were investigated, especially the occurrence of the balling‐processes under different processing conditions. During laser processing, sintered, semi‐sintered/semi‐melted or completely melted cakes can be formed. Size and shape of the laser processed parts can change depending on the energy and time parameters of the laser irradiation and on the properties of initial powder layers.

The purpose of this paper is to investigate the transient three‐dimensional temperature distribution for a laser sintered duraform fine polyamide part by a moving Gaussian laser beam. The primary objective of the present paper is to develop computationally efficient numerical simulation technique with the commercially available finite element software domain for the accurate prediction of the temperature history and heat‐affected zones of the laser sintered parts so as to finally obtain the density of the sintered sample.

The paper proposes a mathematical model of scanning by moving laser beam and sintering sub‐model. Based on the mathematical models, a simulation model was developed by using author written subroutines in ANSYS® 11.0, a general purpose finite element software. The simulation model was then run at experimental designed points using two‐level factorial design of experiments (DOE) approach. The data thus generated were used to predict the equation for the density of sintered part in terms of process parameters using Design Expert software in order to analyse the designed experiments.

Laser power and scan spacing were found to be significant parameters affecting the part density. Amongst the interaction terms, significant effect of laser power was found on the part density at the lower settings of the scan velocity. Temperature‐time plots were generated to study the transient temperature distribution for the sintering process and with further applicability to study the thermal stresses.

The simulation model hence developed can be used for only simple part geometries and cannot be generalised for any complex geometry.

The paper presents a simulation model which is integrated with a DOE approach so as to develop a robust as well as simple and fast approach for the optimization of quality objective.

Rapid prototyping technologies are now evolving toward rapid tooling. The reasons for this extension are found in the need to further reduce the time‐to‐market by shortening not only the development phase, but also the industrialization phase of the manufacturing process. The present state of rapid tooling is reviewed and the direct rapid tooling concept, aimed at developing direct and rapid tool manufacturing processes, is presented, along with three promising methods. Their intrinsic properties are outlined and compared. Necessary research and development are described in terms of direct rapid tooling requirements.

The purpose of this paper is to examine new alloys created from Alumix 431 powder and investigate their mechanical and electrochemical properties.

In this study; Alumix-431 alloy samples were prepared using the powder metallurgy (P/M) method applying cold (RT) and warm (50°C and 80°C) compaction methods under pressures of 200 and 250 MPa and were sintered at 600°C in N₂(g) atmosphere. Hardness and density of the samples were measured, and corrosion properties were determined by electrochemical impedance spectroscopy charting polarization curves. Surface characterization was determined by contact angle, scanning electron microscopy/mapping, energy dispersive X-ray spectrometry and X-ray diffractometry images.

Alumix-431 alloys obtained upon compaction at 250 MPa/50 °C had the highest mechanical properties and corrosion resistance and good surface properties. On the surfaces of Alumix-431 alloys, α-Al, MgZn₂, Al₂,CuMg, Al₂,O₃, Al₂MgO₄ phases were recorded.

This study aimed to construct a correlation between mechanical and electrochemical properties of the newly created alloys (prepared under special conditions).