Processing parameters and post-sintering operations effects in magnesium powder metallurgy

2011 ◽  
Vol 50 (3) ◽  
pp. 240-245 ◽  
Author(s):  
P Burke ◽  
C Petit ◽  
V Vuaroqueaux ◽  
A Doyle ◽  
G J Kipouros
Keyword(s):  
Powder Metallurgy ◽  
Processing Parameters ◽  
Magnesium Powder

Effect of Processing Parameters on Mechanical Properties of Al7175/Boron Carbide (B4C) Composite Fabricated by Powder Metallurgy Techniques

2021 ◽  
Vol 105 ◽  
pp. 8-16
Author(s):  
Guttikonda Manohar ◽  
Krishna Murari Pandey ◽  
Saikat Ranjan Maity
Keyword(s):  
Mechanical Properties ◽  
Composite Material ◽  
Powder Metallurgy ◽  
Sintering Temperature ◽  
Processing Parameters ◽  
Matrix Composites ◽  
Composite Powders ◽  
Porosity Level ◽  
Milling Operations ◽  
Boron Carbide B4c

Metal matrix composites attain a significant position in Industrial, defense, structural and automobile applications. To amplify that strategy there is a need to find out the conditional behavior of the composites and enhancing the properties will be mandatory. The present work mainly investigates on the effect of processing parameters like densification rates, sintering temperature, reinforcement content on the microstructure, mechanical properties of the Al7175/B4C composite material fabricated by mechanical milling and powder metallurgy techniques. Results show there is a grain size reduction and refinement in the composite material through ball milling operations and along with that increasing B4C content in the composite powders make milling conditions very effective. Increasing the sintering temperature results in a consistent grain growth along with that porosity level decreases up to a limit and then attain a steady state, the strength of the composites increases with compaction pressures but reinforcements content effects the strength of the material by losing its ductility making it brittle.

Image Analysis Software for Porosity Measurements in Some Powder Metallurgy Alloys

2017 ◽  
Vol 1143 ◽  
pp. 103-107
Author(s):  
Mihaela Marin ◽  
Florentina Potecaşu ◽  
Octavian Potecaşu ◽  
Florin Bogdan Marin
Keyword(s):  
Image Analysis ◽  
Powder Metallurgy ◽  
Processing Parameters ◽  
Metallographic Analysis ◽  
Analysis Software ◽  
Analysis Techniques ◽  
Image Analysis Software ◽  
Porosity Measurements ◽  
Image Analysis Techniques ◽  
Porosity Fraction

The present research was aimed to study the porosity in some powder metallurgy (P/M) alloys using an image analysis software. The porosity in P/M parts is an important parameter because is affecting the mechanical properties. Also, porosity is in correlation with processing parameters such as green density, alloying elements, particle size. The conventional method for porosity measurements of powder metallurgy products is using the density technique. Another method for porosity measurements was using an image processing software and by applying filters and adjustments the detection of the pores (black areas) was done. Two types of powders obtained by water amotization were subjected to analyze. To obtain the green compacts, the powders were pressed at 600 MPa using a single die action. The green compacts were sintered in a laboratory furnace at 1150o C for 30 and 120 minutes. A metallographic analysis was performed for porosity measurements. The pore’s shape and porosity fraction were measured using both conventional and image analysis techniques. The porosity measurements for sitnered specimens obtained from image analysis was slightly higher than that from density technique.

Effect of Processing Parameters on the Microstructure and Mechanical Behaviour of Nano Bioceramic

2008 ◽  
Author(s):  
Xueran Liu ◽  
Ahmed R. El-Ghannam
Keyword(s):  
Mechanical Properties ◽  
Compressive Strength ◽  
Powder Metallurgy ◽  
Stress Shielding ◽  
Processing Parameters ◽  
Processing Conditions ◽  
Powder Metallurgy Technique ◽  
Regenerative Capacity ◽  
Structural Support ◽  
Superior Mechanical Properties

Silica-calcium phosphate nanocomposite (SCPC) has a superior bone regenerative capacity and resorbability when compared to hydroxyapatie (HA) and bioactive glass [1–2]. Synthesis of SCPC bioceramics with superior mechanical properties has been an important and challenging issue. Ideally, the mechanical strength of the orthopedic implantat should be comparable to that of the host-bone in order to provide structural support and minimize stress shielding. The compressive strength of trabecular bone ranges from 2–12 MPa and that of cortical bone varies in the range of 100–230 MPa [3]. The aim of the present study is to study the effect of processing parameters on the mechanical properties of SCPC cylinders prepared by powder metallurgy technique. The mechanical properties were correlated to the microstructure of SCPC prepared under different processing conditions.

Surprises and Pitfalls in the Development of Magnesium Powder Metallurgy Alloys

2019 ◽  
pp. 337-373
Author(s):  
Paul Burke ◽  
Yiannis G. Kipouros ◽  
William D. Judge ◽  
Georges J. Kipouros
Keyword(s):  
Powder Metallurgy ◽  
Magnesium Powder

Porous Magnesium for Medical Applications - Influence of Powder Size on Mechanical Properties

2013 ◽  
Vol 592-593 ◽  
pp. 342-345 ◽  
Author(s):  
Jaroslav Čapek ◽  
Dalibor Vojtěch
Keyword(s):  
Mechanical Properties ◽  
Powder Metallurgy ◽  
Ammonium Bicarbonate ◽  
Spherical Particles ◽  
Flexural Properties ◽  
Medical Applications ◽  
Powder Size ◽  
Magnesium Powder ◽  
Space Holder ◽  
Porous Magnesium

Porous magnesium materials appear to be promising candidates for scaffold production. In this work we prepared porous magnesium samples by powder metallurgy using ammonium bicarbonate as space-holder particles. We focused on the influence of the magnesium powder size and shape on product characteristics. Samples prepared using magnesium chips showed significantly worse flexural properties than samples with similar porosities prepared from an equi-axed magnesium powder. Therefore, we can conclude that spherical particles are more suitable for the preparation of porous objects by powder metallurgy.

Microstructure Development in Powder Metallurgy Steels: Effect of Alloying Elements and Process Variables

2014 ◽  
Vol 782 ◽  
pp. 467-472 ◽  
Author(s):  
Eduard Hryha ◽  
Lars Nyborg
Keyword(s):  
Powder Metallurgy ◽  
Carbon Sources ◽  
Processing Parameters ◽  
Alloying Elements ◽  
Microstructure Formation ◽  
Prealloyed Powder ◽  
Conventional Sintering ◽  
The Difference ◽  
Characteristic Features ◽  
Effect Of Alloying

Microstructure of the powder metallurgy (PM) steels and especially mechanism of its formation differs significantly from the microstructure of the conventional steels even if composition will be exactly the same. The difference is not only connected to the presence of the pores, which are inalienable feature of the PM parts. Presence of the prior inter-particle boundaries, which can be contaminated by residual oxides, as well as microstructure heterogeneity are another characteristic features of the microstructure of PM steels. Microstructure heterogeneity is connected to the PM manufacturing process: powder mix, consisting of the base powder and additional alloying elements is compacted and then sintered. Fully prealloyed powder is not always possible to use in standard press & sintering route due to the solid solution strengthening of the ferrite resulting in bad powder compressibility. Hence, in order to provide good powder compressibility only pure iron or low-alloyed (typically <3 wt.%) powders are used. Required alloying elements and carbon (added as graphite) are further admixed in the powder form and are distributed during sintering by diffusion into iron particles at high temperatures. To assure satisfactory distribution of alloying elements, oxide layer, covering surface of the powder particles and hindering mass-transfer of the alloying elements, has to be removed first. This can be done by gaseous reducing agents as hydrogen and carbon monoxide. However, their cost and/or purity are of issue for modern alloyed PM steels. Admixed carbon, additionally to its function as alloying element, plays a role of effective reducing agent at higher temperatures. Paper summarizes the main features of microstructure formation during the whole sintering cycle (heating and isothermal sintering) and effect of alloying additives (different carbon sources, alloying elements) and processing parameters (sintering atmosphere composition, temperature profile) on the microstructure formation during conventional sintering process. Results indicate that for successful sintering of alloyed PM steels with homogeneous defect-free microstructure, hydrogen-rich atmospheres and high-temperature sintering are required.

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