Enrique Alejandro López Baltazar - Academia.edu (original) (raw)

Papers by Enrique Alejandro López Baltazar

Metals

Dual Phase (DP) steel, composed of a ferrite matrix with dispersed islands of martensite, has bec... more Dual Phase (DP) steel, composed of a ferrite matrix with dispersed islands of martensite, has become popular in auto-body car construction due to its outstanding mechanical properties (i.e., high strength and good ductility). DP steel softens at the sub-critical heat-affected zone (SC-HAZ) when subjected to welding thermal cycles, owing to the tempering of the martensite phase. In this work, DP980 steel was subjected to varied thermal cycles: (a) furnace-tempering treatment, (b) gas metal arc welding (GMAW), and (c) resistance spot welding (RSW), in order to characterize the tempering of martensite below the Ac1 critical temperature and at the sub-critical heat-affected zone (SC-HAZ) in the case of the welded specimens. The coarsening stage of cementite phase was characterized through microstructure observations and hardness measurements. As expected, the comparative results indicated an advanced stage of the martensite tempering in the furnace heat-treated specimens, followed by th...

Metals

A transformation-induced plasticity (TRIP) steel and a dual-phase (DP) steel were paired together... more A transformation-induced plasticity (TRIP) steel and a dual-phase (DP) steel were paired together by employing gas metal arc welding (GMAW) and laser beam welding (LBW) processes. The post-weld microstructure, the hardness profile, and the uniaxial tensile behavior of the welded steels have been analyzed in detail. The experimental surface residual stress distribution across the weldment was measured through the X-ray diffraction sin2Ψ technique. The results indicate that although a harder microstructure composed of predominant martensite was observed along the weldment, the uniaxial tensile behavior resulted in better elongation properties and a higher UTS in the LBW specimen as compared to the GMAW specimen. The resultant residual stress distribution in the heat-affected zone (HAZ) had an increase to a maximum value, followed by a steady decrease up to the base metal following the trend: upper-critical UC-HAZ (maximum) → inter-critical IC-HAZ (moderated) → subcritical SC-HAZ (lowe...

Revista de Metalurgia

Two macro-roughness patterns namely spiral grooving and diamond knurling were performed on an AIS... more Two macro-roughness patterns namely spiral grooving and diamond knurling were performed on an AISI/SAE 1045 cylindrical steel bar. Al2O3 + 13 wt.-% TiO2 powder was deposited by utilizing a multi-pass torch. Microstructure, microhardness and wear resistance were analyzed. The presence of both γ-Al2O3 and α-Al2O3 throughout the coating was promoted by partially melted and un-melted particles; however, the formation of interlayers of hard α-Al2O3 was influenced by the re-heating during the multi-pass torch causing transformation from γ-Al2O3→α-Al2O3. Knurling pattern specimens contained less defects owe to a suitable splat accommodation thus strengthening the inter-splat anchorage. The improved sliding wear resistance was influenced by both the combination of γ-Al2O3 (toughness) and α-Al2O3 (hardness) phases and, predominantly by the reduced porosity and micro-cracks in specimens with the knurling pattern.

INGENIERÍA: Ciencia, Tecnología e Innovación

En la minería se utiliza el proceso de trituración de mineral, en este proceso algunos elementos ... more En la minería se utiliza el proceso de trituración de mineral, en este proceso algunos elementos de máquina sufren desgaste, estos componentes como martillos y conos trituradores son fabricados de acero Hadfield (ASTM A128) con el 12% al 14% de Mn. El desgaste ocurre cuando estos elementos de máquina tienen contacto directo con partículas abrasivas, debido a esto, y al costo elevado de compra, la recuperación de estas piezas es fundamental, para ello se utiliza el proceso de soldadura SMAW (Shield Metal Arc Welding) para la recuperación a través de depósitos de soldadura mediante electrodos con medio y alto contenido de Cr. En esta investigación se evalúa la microestructura, microdureza y el desgaste por abrasión bajo la norma ASTM G65 de cinco tipos de electrodos comerciales depositados en el acero ASTM A128. Se observó que la cantidad de Cr en el depósito tiene efecto en la cantidad de carburos, donde un aumento de carburos de Cr puede repercutir negativamente en el desgaste abras...

AAustenitic Mn Hadfield (HS) steel is employed in components such as hammers and cone crushers fo... more AAustenitic Mn Hadfield (HS) steel is employed in components such as hammers and cone crushers for obtaining gravel, recently mining sector is looking for minimizing and controlling wear rates. Components subjected to friction wear and abrasion and impact-abrasion wear after a period of time would need to be refurbished. Shielded Metal Arc Welding (SMAW) is a method for repairing those components. In this research three electrode rods have been utilized: Mn, Cr and high Cr base, in which the chemical composition of the electrodes are evaluated, the microstructure and microhardness of three weld deposits are also evaluated and, on the other hand, friction wear and abrasion of HS, as well as sliding wear behavior through pin on disk configuration is employed to evaluated the three weld deposits.El Acero Hadfiel (AH), se utiliza en componentes tales como martillos y conos quebradores para la obtención de grava, y actualmente la minería busca en minimizar y controlar las tasas de desgas...

The influence of varied amounts of Zr on the microstructure, hardness and strength of the shape m... more The influence of varied amounts of Zr on the microstructure, hardness and strength of the shape memory alloy Ti50Ni50-X ZrX % atm. pct. has been analyzed in this work. An electric vacuumed arc furnace was employ in order to add varied fractions of Zr within a range 520 pct. Martensite was observed when Zr additions ranged between 05 pct; whereas, austenite phase was predominantly found if Zr addition reached the range above 1020 pct. Meanwhile, significant increased hardness values are revealed when increasing Zr content, in fact, hardness is higher if contrasted to comparable biomedical materials.En esta investigación se analizó la influencia del % de Zr que fue sustituido por el Ni, en una aleación utilizada como biomaterial con memoria de forma del tipo Ti50Ni50-X ZrX % at, sobre la microestructura, dureza y resistencia mecánica. Se realizó la fundición mediante arco eléctrico, variando las cantidades del Zr desde 5 al 20% at. El resultado fue que al incrementar la cantidad de Zr...

In this work, WC-10Co-4Cr alloy has been deposited by using flame thermal spray processing onto A... more In this work, WC-10Co-4Cr alloy has been deposited by using flame thermal spray processing onto AISI / SAE 1020 steel; further, a laser beam was passed over the coatings in order to modify microstructure and properties. Results indicate the formation of a melted zone (seam) along the laser beam path. The cross-section geometry is affected by varying the operational parameters of the laser system (i.e. power and scan speed). If setting a constant power input and varying the scan speed of the laser system; microstructural changes are clearly observed, therefore, a reduced amount of carbide precipitation, formation of dendritic structure and presence of non-melted particles are obtained with low scan speed. On the other hand, microhardness values were measured up to 550 HV at the center of the generated seam.En este trabajo, una aleación en polvo de WC-10Co-4Cr ha sido depositada utilizando un proceso de rociado térmico por flama sobre un acero AISI / SAE 1020. Posteriormente, se pasó ...

In the present study, the microstructure evolution of WC-10Co-4Cr powder deposited on AISI-SAE 10... more In the present study, the microstructure evolution of WC-10Co-4Cr powder deposited on AISI-SAE 1020 steel substrate by laser cladding was evaluated, considering the e ect of average energy per unit area. Single tracks were obtained by employing a Yb: YAG laser system with selected processing parameters. All samples were sectioned in the transverse direction for further characterization of the cladding. Results showed that dilution lay within 15% and 25%, whereas porosity was measured below 12%. According to microstructural analyses, considerable grain growth is developed within the central area of the cladding (namely, the inner region); additionally, the development of a triangular and/or polygonal morphology for WC particles along with a clear reduction in hardness was observed when employing a high average energy. It is worth noting that, in spite of the rapid thermal cycles developed during laser cladding of WC-10Co-4Cr, grain growth is attributed to a coalescence mechanism due ...

In this project, the effect of the addition of magnesium and lithium in the aluminum alloy for fo... more In this project, the effect of the addition of magnesium and lithium in the aluminum alloy for foundry A380 was investigated, where the mechanical properties and the process of friction stir welding (FSW - Friction Stir Welding) in the alloys were analyzed. The alloys were machined to obtain specimens of tension and hardness, and the plates were welded by means of the FSW process with a heat treated AISI 1045 steel pin, varying only their geometry. For the microstructure analysis, light microscopy and scanning electron microscopy were used, the chemical composition analysis was carried out by means of spark spectrometry and the intermetallics formed by means of EDS were observed. The results show a reduction in density of up to 11.35% compared to the A380 alloy, but likewise a reduction in its mechanical properties.En este proyecto se investigó el efecto de la adición de magnesio y litio en la aleación de aluminio para fundición A380, donde se analizó las propiedades mecánicas y el ...

Memorias del Congreso Internacional Anual de la Sociedad Mexicana de Ingeniería Mecánica Congreso (XXI. - Coatzacoalcos, Ver. -23 al 25 de Septiembre), México pp. 0466-0473, Sep 23, 2015

espanolEn el presente trabajo se realizaron recubrimientos superficiales de carburo de tungsteno ... more espanolEn el presente trabajo se realizaron recubrimientos superficiales de carburo de tungsteno sobre un substrato de acero del tipo AISI 1018 mediante el proceso de rociado termico utilizando tres diferentes tipos de flama: carburante, neutra y oxidante. Los resultados indican que los valores de porosidad son menores bajo condicion de flama carburante con una microestructura compuesta de particulas semi-fundidas y sin fundir, de estructura no laminar, y con presencia de lineas de oxidos. La dureza medida en el recubrimiento de condicion carburante resulto por encima de los 1000Hv debido a la presencia de particulas duras de WC y de W2C. Asi mismo, los recubrimientos realizados bajo condicion de flama carburante resultaron en una resistencia al desgaste bastante aceptable de acuerdo al analisis realizado bajo diferentes condiciones de carga y tiempo de deslizamiento. Finalmente se concluye que las particulas presentes de carburo de tungsteno y la dureza relativamente de estas influ...

BISTUA REVISTA DE LA FACULTAD DE CIENCIAS BASICAS

En el presente trabajo se realizaron recubrimientos superficiales de carburo de tungsteno sobre... more En el presente trabajo se realizaron recubrimientos superficiales de carburo de tungsteno sobre un substrato de acero del tipo AISI 1018 mediante el proceso de rociado térmico utilizando tres diferentes tipos de flama: carburante, neutra y oxidante. Los resultados indican que los valores de porosidad son menores bajo condición de flama carburante con una microestructura compuesta de partículas semi-fundidas y sin fundir, de estructura no laminar, y con presencia de líneas de óxidos. La dureza medida en el recubrimiento de condición carburante resultó por encima de los 1000Hv debido a la presencia de partículas duras de WC y de W2C. Así mismo, los recubrimientos realizados bajo condición de flama carburante resultaron en una resistencia al desgaste bastante aceptable de acuerdo al análisis realizado bajo diferentes condiciones de carga y tiempo de deslizamiento. Finalmente se concluye que las partículas presentes de carburo de tungsteno y la dureza relativamente de éstas influyeron...

Metals

Dual Phase (DP) steel, composed of a ferrite matrix with dispersed islands of martensite, has bec... more Dual Phase (DP) steel, composed of a ferrite matrix with dispersed islands of martensite, has become popular in auto-body car construction due to its outstanding mechanical properties (i.e., high strength and good ductility). DP steel softens at the sub-critical heat-affected zone (SC-HAZ) when subjected to welding thermal cycles, owing to the tempering of the martensite phase. In this work, DP980 steel was subjected to varied thermal cycles: (a) furnace-tempering treatment, (b) gas metal arc welding (GMAW), and (c) resistance spot welding (RSW), in order to characterize the tempering of martensite below the Ac1 critical temperature and at the sub-critical heat-affected zone (SC-HAZ) in the case of the welded specimens. The coarsening stage of cementite phase was characterized through microstructure observations and hardness measurements. As expected, the comparative results indicated an advanced stage of the martensite tempering in the furnace heat-treated specimens, followed by th...

Metals

A transformation-induced plasticity (TRIP) steel and a dual-phase (DP) steel were paired together... more A transformation-induced plasticity (TRIP) steel and a dual-phase (DP) steel were paired together by employing gas metal arc welding (GMAW) and laser beam welding (LBW) processes. The post-weld microstructure, the hardness profile, and the uniaxial tensile behavior of the welded steels have been analyzed in detail. The experimental surface residual stress distribution across the weldment was measured through the X-ray diffraction sin2Ψ technique. The results indicate that although a harder microstructure composed of predominant martensite was observed along the weldment, the uniaxial tensile behavior resulted in better elongation properties and a higher UTS in the LBW specimen as compared to the GMAW specimen. The resultant residual stress distribution in the heat-affected zone (HAZ) had an increase to a maximum value, followed by a steady decrease up to the base metal following the trend: upper-critical UC-HAZ (maximum) → inter-critical IC-HAZ (moderated) → subcritical SC-HAZ (lowe...

Revista de Metalurgia

Two macro-roughness patterns namely spiral grooving and diamond knurling were performed on an AIS... more Two macro-roughness patterns namely spiral grooving and diamond knurling were performed on an AISI/SAE 1045 cylindrical steel bar. Al2O3 + 13 wt.-% TiO2 powder was deposited by utilizing a multi-pass torch. Microstructure, microhardness and wear resistance were analyzed. The presence of both γ-Al2O3 and α-Al2O3 throughout the coating was promoted by partially melted and un-melted particles; however, the formation of interlayers of hard α-Al2O3 was influenced by the re-heating during the multi-pass torch causing transformation from γ-Al2O3→α-Al2O3. Knurling pattern specimens contained less defects owe to a suitable splat accommodation thus strengthening the inter-splat anchorage. The improved sliding wear resistance was influenced by both the combination of γ-Al2O3 (toughness) and α-Al2O3 (hardness) phases and, predominantly by the reduced porosity and micro-cracks in specimens with the knurling pattern.

INGENIERÍA: Ciencia, Tecnología e Innovación

En la minería se utiliza el proceso de trituración de mineral, en este proceso algunos elementos ... more En la minería se utiliza el proceso de trituración de mineral, en este proceso algunos elementos de máquina sufren desgaste, estos componentes como martillos y conos trituradores son fabricados de acero Hadfield (ASTM A128) con el 12% al 14% de Mn. El desgaste ocurre cuando estos elementos de máquina tienen contacto directo con partículas abrasivas, debido a esto, y al costo elevado de compra, la recuperación de estas piezas es fundamental, para ello se utiliza el proceso de soldadura SMAW (Shield Metal Arc Welding) para la recuperación a través de depósitos de soldadura mediante electrodos con medio y alto contenido de Cr. En esta investigación se evalúa la microestructura, microdureza y el desgaste por abrasión bajo la norma ASTM G65 de cinco tipos de electrodos comerciales depositados en el acero ASTM A128. Se observó que la cantidad de Cr en el depósito tiene efecto en la cantidad de carburos, donde un aumento de carburos de Cr puede repercutir negativamente en el desgaste abras...

AAustenitic Mn Hadfield (HS) steel is employed in components such as hammers and cone crushers fo... more AAustenitic Mn Hadfield (HS) steel is employed in components such as hammers and cone crushers for obtaining gravel, recently mining sector is looking for minimizing and controlling wear rates. Components subjected to friction wear and abrasion and impact-abrasion wear after a period of time would need to be refurbished. Shielded Metal Arc Welding (SMAW) is a method for repairing those components. In this research three electrode rods have been utilized: Mn, Cr and high Cr base, in which the chemical composition of the electrodes are evaluated, the microstructure and microhardness of three weld deposits are also evaluated and, on the other hand, friction wear and abrasion of HS, as well as sliding wear behavior through pin on disk configuration is employed to evaluated the three weld deposits.El Acero Hadfiel (AH), se utiliza en componentes tales como martillos y conos quebradores para la obtención de grava, y actualmente la minería busca en minimizar y controlar las tasas de desgas...

The influence of varied amounts of Zr on the microstructure, hardness and strength of the shape m... more The influence of varied amounts of Zr on the microstructure, hardness and strength of the shape memory alloy Ti50Ni50-X ZrX % atm. pct. has been analyzed in this work. An electric vacuumed arc furnace was employ in order to add varied fractions of Zr within a range 520 pct. Martensite was observed when Zr additions ranged between 05 pct; whereas, austenite phase was predominantly found if Zr addition reached the range above 1020 pct. Meanwhile, significant increased hardness values are revealed when increasing Zr content, in fact, hardness is higher if contrasted to comparable biomedical materials.En esta investigación se analizó la influencia del % de Zr que fue sustituido por el Ni, en una aleación utilizada como biomaterial con memoria de forma del tipo Ti50Ni50-X ZrX % at, sobre la microestructura, dureza y resistencia mecánica. Se realizó la fundición mediante arco eléctrico, variando las cantidades del Zr desde 5 al 20% at. El resultado fue que al incrementar la cantidad de Zr...

In this work, WC-10Co-4Cr alloy has been deposited by using flame thermal spray processing onto A... more In this work, WC-10Co-4Cr alloy has been deposited by using flame thermal spray processing onto AISI / SAE 1020 steel; further, a laser beam was passed over the coatings in order to modify microstructure and properties. Results indicate the formation of a melted zone (seam) along the laser beam path. The cross-section geometry is affected by varying the operational parameters of the laser system (i.e. power and scan speed). If setting a constant power input and varying the scan speed of the laser system; microstructural changes are clearly observed, therefore, a reduced amount of carbide precipitation, formation of dendritic structure and presence of non-melted particles are obtained with low scan speed. On the other hand, microhardness values were measured up to 550 HV at the center of the generated seam.En este trabajo, una aleación en polvo de WC-10Co-4Cr ha sido depositada utilizando un proceso de rociado térmico por flama sobre un acero AISI / SAE 1020. Posteriormente, se pasó ...

In the present study, the microstructure evolution of WC-10Co-4Cr powder deposited on AISI-SAE 10... more In the present study, the microstructure evolution of WC-10Co-4Cr powder deposited on AISI-SAE 1020 steel substrate by laser cladding was evaluated, considering the e ect of average energy per unit area. Single tracks were obtained by employing a Yb: YAG laser system with selected processing parameters. All samples were sectioned in the transverse direction for further characterization of the cladding. Results showed that dilution lay within 15% and 25%, whereas porosity was measured below 12%. According to microstructural analyses, considerable grain growth is developed within the central area of the cladding (namely, the inner region); additionally, the development of a triangular and/or polygonal morphology for WC particles along with a clear reduction in hardness was observed when employing a high average energy. It is worth noting that, in spite of the rapid thermal cycles developed during laser cladding of WC-10Co-4Cr, grain growth is attributed to a coalescence mechanism due ...

In this project, the effect of the addition of magnesium and lithium in the aluminum alloy for fo... more In this project, the effect of the addition of magnesium and lithium in the aluminum alloy for foundry A380 was investigated, where the mechanical properties and the process of friction stir welding (FSW - Friction Stir Welding) in the alloys were analyzed. The alloys were machined to obtain specimens of tension and hardness, and the plates were welded by means of the FSW process with a heat treated AISI 1045 steel pin, varying only their geometry. For the microstructure analysis, light microscopy and scanning electron microscopy were used, the chemical composition analysis was carried out by means of spark spectrometry and the intermetallics formed by means of EDS were observed. The results show a reduction in density of up to 11.35% compared to the A380 alloy, but likewise a reduction in its mechanical properties.En este proyecto se investigó el efecto de la adición de magnesio y litio en la aleación de aluminio para fundición A380, donde se analizó las propiedades mecánicas y el ...

Memorias del Congreso Internacional Anual de la Sociedad Mexicana de Ingeniería Mecánica Congreso (XXI. - Coatzacoalcos, Ver. -23 al 25 de Septiembre), México pp. 0466-0473, Sep 23, 2015

espanolEn el presente trabajo se realizaron recubrimientos superficiales de carburo de tungsteno ... more espanolEn el presente trabajo se realizaron recubrimientos superficiales de carburo de tungsteno sobre un substrato de acero del tipo AISI 1018 mediante el proceso de rociado termico utilizando tres diferentes tipos de flama: carburante, neutra y oxidante. Los resultados indican que los valores de porosidad son menores bajo condicion de flama carburante con una microestructura compuesta de particulas semi-fundidas y sin fundir, de estructura no laminar, y con presencia de lineas de oxidos. La dureza medida en el recubrimiento de condicion carburante resulto por encima de los 1000Hv debido a la presencia de particulas duras de WC y de W2C. Asi mismo, los recubrimientos realizados bajo condicion de flama carburante resultaron en una resistencia al desgaste bastante aceptable de acuerdo al analisis realizado bajo diferentes condiciones de carga y tiempo de deslizamiento. Finalmente se concluye que las particulas presentes de carburo de tungsteno y la dureza relativamente de estas influ...

BISTUA REVISTA DE LA FACULTAD DE CIENCIAS BASICAS

En el presente trabajo se realizaron recubrimientos superficiales de carburo de tungsteno sobre... more En el presente trabajo se realizaron recubrimientos superficiales de carburo de tungsteno sobre un substrato de acero del tipo AISI 1018 mediante el proceso de rociado térmico utilizando tres diferentes tipos de flama: carburante, neutra y oxidante. Los resultados indican que los valores de porosidad son menores bajo condición de flama carburante con una microestructura compuesta de partículas semi-fundidas y sin fundir, de estructura no laminar, y con presencia de líneas de óxidos. La dureza medida en el recubrimiento de condición carburante resultó por encima de los 1000Hv debido a la presencia de partículas duras de WC y de W2C. Así mismo, los recubrimientos realizados bajo condición de flama carburante resultaron en una resistencia al desgaste bastante aceptable de acuerdo al análisis realizado bajo diferentes condiciones de carga y tiempo de deslizamiento. Finalmente se concluye que las partículas presentes de carburo de tungsteno y la dureza relativamente de éstas influyeron...