Compaction Issues in Powder Metallurgy

MRS Bulletin ◽  
1997 ◽  
Vol 22 (12) ◽  
pp. 29-33 ◽  
Author(s):  
William R. Blumenthal ◽  
Haskell Sheinberg ◽  
Sherri A. Bingert
Keyword(s):  
Powder Metallurgy ◽  
Processing Conditions ◽  
Step Process ◽  
Critical Step ◽  
Uniform Microstructure ◽  
Processing Variables ◽  
Shaped Part ◽  
Key Variables ◽  
Multiple Step ◽  
Low Porosity

Powder metallurgy (P/M) involves a multiple-step process to prepare and consolidate granulated metal and composites into near-net-shaped components. The modern P/M method starts with a precisely defined final geometry and a set of properties for a desired component. Decisions are then made about a variety of processing variables, recognizing that many variables strongly interact counter to the desired properties. Finally preproduction fabrication trials are conducted to optimize key variables until he specifications are achieved, and the processing conditions are established. A critical step in the overall process is the compaction of powder into a sufficiently strong, low-porosity, properly shaped part with uniform microstructure that can be sintered, or alternately heated and pressed to the final dimensions and properties.

Powder Metallurgy Aluminum Alloys: Structure and Porosity

2019 ◽  
Author(s):  
Will Judge ◽  
Georges Kipouros
Keyword(s):  
Powder Metallurgy ◽  
Aluminum Alloys ◽  
Material Properties ◽  
Cost Effective ◽  
High Reactivity ◽  
Commercial Production ◽  
Processing Conditions ◽  
Near Net Shape ◽  
And Performance ◽  
Production Conditions

The production of aluminum alloys through powder metallurgy (PM) processes allows for the manufacture of net- or near-net-shape components in a cost-effective and sustainable manner. The high reactivity of aluminum metal, however, complicates PM processing, and special attention must be given to certain steps during production, particularly sintering. PM processing conditions strongly affect the structure and porosity of aluminum PM alloys, which ultimately determine their material properties and performance. In this article, the fundamental aspects of the commercial production of aluminum PM alloys are presented, along with the effects of production conditions on the structure and porosity of aluminum PM alloys. The properties and performance of aluminum PM alloys are then analyzed and interpreted with respect to their structure and porosity.

Sintering Densification in Fabrication of Particle Reinforced Ceramic

2012 ◽  
Vol 184-185 ◽  
pp. 1194-1197
Author(s):  
Bin Li ◽  
Hong Wang
Keyword(s):  
Microstructure Evolution ◽  
Processing Conditions ◽  
Processing Variables

Particle reinforced ceramics can be fabricated by a variety of methods, some of which have their origins in early civilization. The key objective of sintering studies is therefore to understand how the processing variables influence the microstructure evolution. In this way, useful information can be provided for the practical effort of designing processing conditions for producing the required microstructure.

Development and Psychometric Testing of the Postpartum Depression Screening Scale: Hungarian Version

2012 ◽  
Vol 16 (1) ◽  
pp. 54-58
Author(s):  
Kathryn Stewart Hegedus, ◽  
Cheryl Tatano Beck,
Keyword(s):  
Postpartum Depression ◽  
Psychometric Testing ◽  
Depression Screening ◽  
Convenience Sample ◽  
Semantic Equivalence ◽  
Step Process ◽  
Postpartum Depression Screening Scale ◽  
Hungarian Version ◽  
Screening Scale ◽  
Multiple Step

The purpose of this study was to ensure the semantic equivalence of the Hungarian version of the Postpartum Depression Screening Scale (PDSS) (Beck & Gable, 2002). a multiple-step process was used to translate the scale. first, the PDSS was translated into Hungarian. Secondly, this version was blindly back translated to English. Third, a panel of three Hungarian-American mothers met with one researcher and reviewed the items. Finally, a linguist read the scale for syntax and grammar. A convenience sample of Hungarian-American mothers (n = 30) participated in the study. Correlation between the English and Hungarian scales was high (r = .97, p <.01).

scholarly journals Couches Conductrices et Transparentes Obtenues par Pulverisation d'une Cible de SnO2

1976 ◽  
Vol 2 (4) ◽  
pp. 223-231 ◽  
Author(s):  
J. Launey ◽  
A. Tosser
Keyword(s):  
Thin Films ◽  
Visible Light ◽  
Optical Transmission ◽  
Thermal Evolution ◽  
Thermal Ageing ◽  
Step Process ◽  
Transmission Data ◽  
Sous Vide ◽  
Conductive Thin Films ◽  
Multiple Step

SnO2is reactively r.f. sputtered to obtain conductive thin films of good optical transmission. Data about thermal ageing in vacuum, thermal evolution of conductivity, spontaneous ageing in air and optical transmission show how it is possible to obtain a transmission of 80% in visible light with resistance square below 1 kΩ/sq; the possibility of a multiple-step process of sputtering is presented. A “nucleation-growth” model allows an explanation of the observed phenomena.La pulvérisation haute-fréquence d'une cible de SnO2en présence d'argon et d'oxygène permet d'obtenir des couches minces conductrices de bonne transparence optique. A partir des phénomènes de recuit sous vide, d'évolution de la résistance avec la température, du vieillissement spontané à l'air et de la variation de la transparence optique, il est possible de déterminer la méthode permettant d'obtenir un facteur de transmission de 80% en lumière visible et une résistance carrée inférieure à 1 kΩ/sq; l'intérêt d'une pulvérisation fractionnée est explicité. Le modèle de “germination-croissance” permet une description convenable des phénomènes observés.

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.

scholarly journals Metagenomic Sequencing for Identification of Xylella fastidiosa from Leaf Samples

mSystems ◽  
2021 ◽  
Vol 6 (5) ◽  
Author(s):  
Verónica Román-Reyna ◽  
Enora Dupas ◽  
Sophie Cesbron ◽  
Guido Marchi ◽  
Sara Campigli ◽  
...  
Keyword(s):  
Host Range ◽  
Geographical Distribution ◽  
Xylella Fastidiosa ◽  
Detection Limits ◽  
Metagenomic Sequencing ◽  
Content Type ◽  
Step Process ◽  
Diagnostic Approaches ◽  
Multiple Step

Destructive Xylella fastidiosa ( Xf ) outbreaks in Europe highlight this pathogen’s capacity to expand its host range and geographical distribution. The current disease diagnostic approaches are limited by a multiple-step process, biases to known sequences, and detection limits.

Preparation of Nanoemulsion

2022 ◽  
pp. 24-43
Author(s):  
Elaine Elaine ◽  
Kar Lin Nyam
Keyword(s):  
Delivery System ◽  
Processing Parameters ◽  
Optimization Process ◽  
Processing Conditions ◽  
Related Field ◽  
Future Studies ◽  
Processing Variables

Nanoemulsion is a versatile emulsion-based delivery system that can be structured or prepared with different compositions, methods, or processing variables. Although single nanoemulsion has been a promising delivery carrier in numerous industries, the innovation of double nanoemulsion is introduced to provide different benefits. However, the nanoemulsion must be optimized in terms of the composition and emulsification methods to maintain the integrity of the delivery system. Therefore, the optimization of nanoemulsion can range from deciding the type and concentration of compositions (aqueous, lipid, surfactants) to the processing conditions during emulsification. The current options of emulsification methods, processing parameters, and optimization process of nanoemulsion are highlighted and elaborated in this chapter. This allows readers to understand the fundamental principles of nanoemulsion preparation and encourage future studies and applications in the related field.

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