Nonequilibrium microstructures and phase evolutions of an iron-based laser clad coating

The microstructural and compositional features of the laser-solidified microstructures and phase evolutions occurring during high temperature tempering were investigated by using analytical electron microscopy with energy dispersive X-ray analysis. The cladded alloy, a powder mixture of Fe, Cr, W, Ni and C with a weight ratio of 10:5:1:1:1, was processed with a 3 kW continuous wave CO2 laser. The cladded coating possessed the hypoeutectic microstructure of the primary dendritic gamma-austenite and interdendritic eutectic consisting of (gamma+M7C3). The gamma-austenite is a nonequilibrium phase with extended solid solution of alloying elements. And, a great deal of fine structures, i.e., a high density of dislocations, twins, and stacking faults existed in austenite phase. During high temperature aging, the precipitation of M23C6, MC and M2C in austenite and in situ transformation of M7C3(+gamma) --> M23C6 and M7C3+gamma --> M6C occurred. The laser clad coating revealed an evident secondary hardening and superior impact wear resistance.

Rapidly solidified nonequilibrium microstructure and phase transformation of laser-synthesized iron-based alloy coating

The rapidly solidified microstructural and compositional features, the precipitation and transformation of carbides during tempering, and the impact wear resistance of an iron-based alloy coating prepared by laser cladding are investigated. The clad coating alloy, a powder mixture of Fe, Cr, W, Ni, and C with a weight ratio of 10:5:1.1.1, is processed using a continuous wave CO, laser. Microstructural studies demonstrate that the coating possesses the hypoeutectic microstructure comprising the primary dendritic gamma-austenite and interdendritic eutectic consisting of gamma-austenite and M7C3 carbides. gamma-Austenite is a non-equilibrium phase with an extended solid solution of alloying elements. During high temperature tempering at 963 K for 1 h, the precipitation of M23C6, MC and M2C carbides in austenite and in situ carbide transformation of M7C3 to M23C6 and M7C3 to M6C respectively are observed. In addition, the microstructure of the laser-clad coating reveals an evident secondary hardening and a superior impact wear resistance.

Recently discovered Iron Age lion figurines from Jerusalem

Abstract: More than 500 Iron Age figurines were discovered in the 2005–2010 Western Wall Plaza excavations in Jerusalem.1 The excavations revealed a large building, probably of the four-room type. Many figurines were discovered in this building, others in fills below and above it, dating in general to the eighth-sixth centuries BCE. Here we focus on two heads most likely depicting lions, one of them exceptional—holding another animal in its mouth. We discuss the identification of these figurines as lions, the lion motif in a variety of media in the Southern Levant, and finally recent theories concerning lions in the Hebrew Bible and their relation to Yahweh. We suggest that the two Western Wall Plaza figurines represent lions as wild animals, in similarity to other figurines of wild animals made on occasion by Judean coroplasts.

Molecular dynamics studies on dislocations in crystallites of nanocrystalline alpha-iron

Molecular dynamics simulations have been carried our to study the atomic structure of the crystalline component of nanocrystalline alpha-iron. A two-dimensional computational block is used to simulate the consolidation process. It is found that dislocations are generated in the crystallites during consolidation when the grain size is large enough. The critical value of the grain size for dislocation generation appears to be about 9 nm. This result agrees with experiment qualitatively. AN dislocations that are preset in the original grains glide out during consolidation. It shows that dislocations in the crystallites we generated in consolidation process, but not in the original grains. Higher consolidation pressure results in more dislocations. Furthermore, new interfaces are found within crystallites. These interfaces might result from the special environment of nanomaterial. (C) 1998 Acta Metallurgica Inc.

A atuação da esquerda no processo constituinte : 1986-1988

Descreve os mecanismos de produção do texto constitucional com uma análise ampla do processo político brasileiro na conjuntura de crise e superação da ditadura militar, processo no qual se inseriram os trabalhos da Constituinte de 1986-1988. Focaliza a dinâmica interna da Constituinte, tratando de aspectos variados como o regimento da Constituinte, a formação de suas comissões, a ação dos blocos parlamentares, a diversidade de comportamento dos partidosde acordo com o tipo de questão em jogo, sem tirar os olhos dos determinantes políticos mais gerais que a condicionavam - o fato de se tratar de um Congresso Constituinte, e não de uma Constituinte exclusiva e soberana, a pressão dos militares, da grande imprensa e do movimento popular.

O processo legislativo, o orçamento público e a Casa Legislativa

Reúne artigos sobre o processo legislativo e seus impactos na democracia, sobre o orçamento e políticas públicas e sobre assuntos pertinentes à Casa Legislativa, abrangendo os aspectos da gestão estratégica, da informação legislativa e da participação da Câmara dos Deputados em ações de sustentabilidade, tendo como foco o programa de coleta seletiva.

A lei complementar e o seu processo de elaboração na Câmara dos Deputados

Estudo da teoria referente à lei complementar. Discussão sobre a elaboração da lei complementar. Análise de dados na tramitação dos projetos de lei complementar na Câmara dos Deputados. Pesquisa sobre a ocorrência de dois turnos de discussão e votação nos projetos de lei complementar transformados em norma jurídica a partir de 1989.

Em busca de uma participação mais efetiva do Congresso no processo de elaboração orçamentária

Aborda aspectos relacionados à pressão exercida pelos parlamentares federais para a inclusão de novas dotações na lei orçamentária anual (LOA), sem que seja realizada uma análise das políticas públicas propostas, de forma a priorizar aquelas que julgarem mais relevantes.

Recursos no processo penal

Consultoria Legislativa - Área II - Direito Civil e Processual Civil, Direito Penal e Processual Penal, de Família, do Autor, de Sucessões, Internacional Privado.