Stage Of Liquid State Research Articles

Formation of chromium hydride in chromium being electrodeposited alloyed with hydrogen

The aim of the work was experimental verification of validity of the recently discovered phenomenon of phase formation through a stage of liquid state in metals being electrodeposited. The idea of the work was based on the known fact, that during crystallization of liquid phase of a transitional metal (e.g. chromium) alloyed in significant concentration with non-metal of minor atomic radius (e.g. hydrogen) intermediate phases with simple crystal lattices (e.g. hydrides) appear. Therefore, if in electrodeposited chromium alloyed with hydrogen the chromium hydride will be detected, this result will indicate validity of the phenomenon of phase formation through a stage of liquid state in metals being electrodeposited. To find the variants of chromium alloying with hydrogen during its electrodeposition the method for estimation of the degree of hydrogen saturation of metals being electrodeposited was developed. Electrodeposition of chromium was accomplished in such conditions where the volume of hydrogen being formed on the cathode was 62700 times higher than the volume of chromium being formed, which indicated alloying of chromium during its electrodeposition with hydrogen in significant concentration. On the basis of the accomplished experiments the formation of chromium hydride during electrodeposition of chromium alloyed with hydrogen was found. The conclusion, that existence of intermediate phases in electrodeposited metals is a result of crystallization of liquid metallic phase being formed during electrochemical deposition of metals, was made. The obtained result proves the validity of the phenomenon of phase formation through a stage of liquid state in metals being electrodeposited.

Next Experimental Confirmation of Validity of the Phenomenon of Phase Formation Through a Stage of Liquid State in Metals Being Electrodeposited

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New Experimental Proofs of Validity of the Phenomenon of Electrochemical Phase Formation of Metallic Materials through a Stage of Liquid State

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СтруктурообразованиЕ металлоВ прИ электроосажденИИ И затвердеванИИ В срЕдЕ водородА

The identity of crystalline structure type of cobalt obtained by electrodeposition in solution and by solidification of melt in saturated environment of hydrogen is found. The obtained result proves the validity of the phenomenon of electrochemical phase formation of metallic materials through a stage of liquid state

Увеличение плотности электроосаждаемых металлов под действием центробежной силы

The effect of increase of density of metals being electrodeposited under the influence of a centrifugal force acting perpendicularly to the crystallization front is found. The obtained result proves the validity of the phenomenon of electrochemical phase formation of metallic materials through a stage of liquid state

РазвитиЕ осадкоВ электроосаждаемыХ металлоВ зА краеМ кАтодА прИ силовоМ воздействИИ

Primary development of the deposits of metals being electrodeposited beyond the edge of the cathode in the direction of the action of a centrifugal force parallel to the crystallization front is found. The obtained result proves the validity of the phenomenon of electrochemical phase formation of metallic materials through a stage of liquid state

Phase and Structure Formation of Metallic Materials Electrodeposited via a Liquid State Stage: New Experimental Proof

On the basis of the discovered phenomenon of phase and structure formation of metallic materials being electrodeposited through a stage of liquid state it was predicted and experimentally proved the following: a) formation of intermediate phases in the form of intermetallides in electrodeposited metallic alloys during the electrochemical crystallization of a liquid phase of two metals of different valences; b) formation of intermediate phases with complex crystal lattices in the form of carbides during solidification of a liquid phase of a transition metal alloyed with carbon; and c) formation of eutectics in electrodeposited metallic alloys as a result of decomposition of a liquid phase into two separate solid phases during its solidification. Intermetallides Cu5Zn8 and Cu6Sn5 in electrodeposited alloys of Cu-Zn and Cu-Sn systems, carbides Fe3C and Cr3C2 in electrodeposited iron and chromium alloyed with carbon, and eutectics in electrodeposited alloys of Sn-Zn and Pb-Cu systems were found.

ФормированиЕ интерметаллидоВ В металлическиХ сплаваХ прИ электрохимическоЙ крИсталлИзацИИ

On the basis of model experiments the formation of intermetallic compounds in metal alloys during electrocrystallization was found. The existence of intermetallic compounds in electrodeposited alloys proves the validity of the concept that metallic materials in the process of electrochemical crystallization pass through a stage of liquid state.

Electrochemical Phase Formation of Metallic Materials through a Stage of Liquid State: New Experimental Proofs

not Available.

A new approach of creating Au‐Sn solder bumps from electroplating

AbstractA homogeneous melting eutectic Au/Sn solder bump for laser chip application has been developed. The under‐bump metallization consists of a Ni wetting layer, a plating seed layer of Pt/Au/Ti multi‐layer scheme. The solder is electroplated as a sequence of Ni, Au and Sn layers. The bump can be exposed to multi‐step reflow cycles. The reflow of the solder as plated starts with a phase forming process in the solid state which results in an eutectic‐like phase and the near eutectic dand z phases. The dand z phases dissolve during the liquid state stage of the reflow at temperatures between 300 and 350 °C. (© 2006 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)

Au–Sn solder bumps with tungsten silicide based barrier metallization schemes

A homogeneous melting eutectic Au/Sn solder bump for flip-chip application has been developed. The underbump metallization consists of a WSi0.4N0.2-layer and a Ni-wetting layer. The solder is deposited as a sequence of alternating Au and Sn layers. The bump can be exposed to multiple fluxless reflow cycles. The reflow of the solder as deposited starts with a phase forming process in the solid state which results in an eutecticlike phase and the near eutectic δ and ζ phases. The δ and ζ phases dissolve during the liquid state stage of the reflow at temperatures between 300 and 350 °C.