Lead Hardening by Oxide Dispersion

Lead hardened through oxide scattering is investigated as raw materials for the fabrication of the support gratings of lead accumulators in order to increase their life service. For the preparation of lead powder hardened through oxide scattering we used air jet pulverisation, a technique specific to powder metallurgy. Two research approaches are presented in the paper: one in which the oxide was introduced through oxidised lead powder, and the other in which additional lead oxide was introduced. Oxide dispersion into metallic matrix was achieved by pronounced deformation through extrusion of the powder. During extrusion, the particles are compelled to pass through the mould calibration zone and consequently they are considerably deformed. As an effect of this deformation, the particles of fragile oxide which cover the lead powder particles are crashed and carried away to the material flowing through the matrix longitudinally on the extruded semiproduct. The content of oxide introduced in matrix by the oxidised lead powder depends on the powder particle size. This paper presents the effect of the powder particle size and oxide phase dispersion in the metallic matrix on the mechanical, chemical and electrical properties of the extruded semi-products. The semi-products made from lead powder belonging to the grain size class of < 40 µm and oxide particles allowance have the highest mechanical resistance and the best corrosion behaviour. Using controlled oxidised lead powder better extruded semi-products are obtained in terms of mechanical resistance, corrosion behaviour and electrical conductivity as compared with lead and Pb-Sb alloy. A higher electrical conductivity represents an important advantage especially for the starting accumulators where the voltage fall should be as low as possible.

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Behavior of Microwave Heating of 316 Stainless Steel Green Body

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.936.1694 ◽

2014 ◽

Vol 936 ◽

pp. 1694-1700

Author(s):

Zhi Wei Li ◽

Kai Yong Jiang ◽

Fei Wang ◽

Ji Liang Zhang

Keyword(s):

Particle Size ◽

Stainless Steel ◽

Microwave Heating ◽

Powder Particle ◽

Microwave Power ◽

Arc Discharge ◽

Steel Powder ◽

Powder Particle Size ◽

Auxiliary Heating ◽

316 Stainless Steel

This paper mainly introduces the mechanism of microwave heating: electric conduction loss, eddy current loss and arc discharge. The microwave heating behavior of 316 stainless steel powder body which made by gel casting was investigated in the paper. Experiments on different microwave power, powder particle size, and the content of auxiliary heating material showed that the smaller the powder particle size, the larger microwave power and auxiliary heating materials help 316 stainless steel body for sintering.

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Microstructure and Properties of TiC-CrNiMo SHS Spray Powder and Thermally Sprayed Coating

Thermal Spray 2000: Proceedings from the International Thermal Spray Conference ◽

10.31399/asm.cp.itsc2000p0429 ◽

2000 ◽

Author(s):

M. Väisänen ◽

P. Vuoristo ◽

T. Mäntylä ◽

V. Maunu ◽

P. Lintunen ◽

...

Keyword(s):

Particle Size ◽

Corrosion Behaviour ◽

Metallic Matrix ◽

Electrochemical Corrosion ◽

Wear Test ◽

Spherical Shape ◽

Open Circuit ◽

Hvof Spraying ◽

Particle Size Range ◽

Abrasion Wear

Abstract Titanium carbide cermet spray powder was produced by the SHS process (Self-propagating High-temperature Synthesis) using elemental Ti, C, Mo and prealloyed CrNiMo powders as starting materials. The powder was characterised (particle size distribution, phase structure, morphology) and the internal structure of each cermet particle was found out to be dense consisting of fine distribution of carbides embedded in a metallic matrix. The particle size range suitable for thermal spraying was obtained by sieving and air classifying. The coatings were prepared by HVOF spraying (DJH2600 and DJH2700). The dry abrasion wear resistance was evaluated by the rubber wheel abrasion wear test and electrochemical corrosion behaviour by open circuit potential measurements. According to the XRD analysis the amount of retained carbides in the coatings is high and the carbide phase has a spherical shape also in the coatings. The microstructure of coatings obtained is dense and the coatings possess good properties in wear and corrosion tests. WC-Co-Cr and Cr3C2-NiCr powders were used for comparison.

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Influence of Changes in the Powder Particle Size Distribution on the Physical Properties of Luting Agents. Mainly on Influence of Pretreatments of Abutment Tooth before Final Cementation.

Nihon Hotetsu Shika Gakkai Zasshi ◽

10.2186/jjps.38.1093 ◽

1994 ◽

Vol 38 (5) ◽

pp. 1093-1101

Author(s):

Futoshi Komine ◽

Kazuhiro Touma ◽

Masataka Shibuya ◽

Tsutomu Yanagisawa ◽

Kazuki Shimada ◽

...

Keyword(s):

Particle Size ◽

Particle Size Distribution ◽

Physical Properties ◽

Size Distribution ◽

Powder Particle ◽

Powder Particle Size ◽

Luting Agents

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Influence of nitrogen and air atmosphere during thermal treatment on micro and nano sized powders and sintered TiO2 specimens

Science of Sintering ◽

10.2298/sos1403365l ◽

2014 ◽

Vol 46 (3) ◽

pp. 365-375

Author(s):

N. Labus ◽

S. Mentus ◽

Z.Z. Djuric ◽

M.V. Nikolic

Keyword(s):

Phase Transition ◽

Particle Size ◽

Powder Particle ◽

Rutile Phase ◽

Nitrogen Atmosphere ◽

Powder Particle Size ◽

Nano Tio2 ◽

Thermo Gravimetric ◽

Air Atmosphere ◽

Thermal Techniques

The influence of air and nitrogen atmosphere during heating on TiO2 nano and micro sized powders as well as sintered polycrystalline specimens was analyzed. Sintering of TiO2 nano and micro powders in air atmosphere was monitored in a dilatometer. Non compacted nano and micro powders were analyzed separately in air and nitrogen atmospheres during heating using thermo gravimetric (TG) and differential thermal analysis (DTA). The anatase to rutile phase transition temperature interval is influenced by the powder particle size and atmosphere change. At lower temperatures for nano TiO2 powder a second order phase transition was detected by both thermal techniques. Polycrystalline specimens obtained by sintering from nano powders were reheated in the dilatometer in nitrogen and air atmosphere, and their shrinkage is found to be different. Powder particle size influence, as well as the air and nitrogen atmosphere influence was discussed.

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Effect the Ratio and Particle Size of Glass Powder from Fluorescent Tubes Waste on Electrical Properties of PVA-Glass Composites

NeuroQuantology ◽

10.14704/nq.2021.19.10.nq21165 ◽

2021 ◽

Vol 19 (10) ◽

pp. 106-114

Author(s):

Hani M Hussien

Keyword(s):

Electrical Conductivity ◽

Particle Size ◽

Dielectric Constant ◽

Glass Powder ◽

Dissipation Factor ◽

Powder Particle Size ◽

Casting Method ◽

Glass Composites ◽

Mixing Ratios ◽

Solution Casting Method

The polymer composites used in the present study were made of polyvinyl alcohol (PVA) as a matrix and glass powder as a filler. The glass powder was obtained from fluorescent tubes waste. The solution casting method was used to fabricate PVA/glass powder composite. Three groups of samples were prepared. The first was prepared by using PVA with the addition of glass powder (sieved less than 20 μm) in proportions 10, 20, 30, 40, and 50 %. The second: the mixing ratios of PVA and glass powder were 80% and 20%, respectively. The third: The mixing ratios of PVA and glass powder were 60% and 40%, respectively. In Both previous groups, the added glass powder used was sieved with sizes less than 20, 45, 105, and 125 μm. For all samples, the following properties were measured at room temperature: DC electrical conductivity, dielectric constant, electrical conductivity, and dissipation factor. The last three properties were measured with a range of frequencies from 1kHz to 5MHz. DC conductivity increases with increasing of glass powder. It was found that the highest conductivity values are for samples composed of glass powder with a particle size of less than 45 μm for both ratios of glass 20% and 40%. It is also noticed that within most frequencies, the sample with 30% glass has the largest dissipation factor. At 20% filler of glass powder, it is noted that the highest values of the dielectric constant are for samples composed of glass powder with a particle size of less than 45 μm and 125 μm. Below 1 MHz, the effect of glass powder particle size on the AC conductivity is minimal. It is found that the samples containing glass powder (less than 125 μm and 105 μm), have similar and lowest dissipation factor. At 40% filler of glass powder, it is noted that the lowest values of the dielectric constant are for samples composed of glass powder with a particle size little than 105 μm.

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Effect of Tungsten Powder Particle Size and Shape on Consolidation and Microstructure of W-xCu Composites by Selective Laser Melting

Chinese Journal of Lasers ◽

10.3788/cjl201643.0203007 ◽

2016 ◽

Vol 43 (2) ◽

pp. 0203007

Author(s):

闫岸如 Yan Anru ◽

杨恬恬 Yang Tiantian ◽

王燕灵 Wang Yanling ◽

马志红 Ma Zhihong ◽

杜云 Du Yun ◽

...

Keyword(s):

Particle Size ◽

Selective Laser Melting ◽

Powder Particle ◽

Tungsten Powder ◽

Powder Particle Size ◽

Laser Melting ◽

Size And Shape ◽

Particle Size And Shape

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Influence of the Powder Particle Size on the Denudated Zone Width at Selective Laser Melting

Materials Science Forum ◽

10.4028/www.scientific.net/msf.989.816 ◽

2020 ◽

Vol 989 ◽

pp. 816-820

Author(s):

Roman Sergeevich Khmyrov ◽

R.R. Ableyeva ◽

Tatiana Vasilievna Tarasova ◽

A.V. Gusarov

Keyword(s):

Particle Size ◽

Selective Laser Melting ◽

Powder Particle ◽

Powder Particle Size ◽

Adhesion Forces ◽

Laser Melting ◽

Friction Forces ◽

Single Bead ◽

Powder Particles

Mass transfer in the laser-interaction zone at selective laser melting influences the quality of the obtained material. Powder particles displacement during the formation of the single bead is experimentally studied. The so-called denudated zone was visualized by metallography. It was determined that increasing the powder particle size leads to widening the denudated zone. This can signify that the adhesion forces between powder particles prevail over the friction forces.

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