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Yu Zhou - One of the best experts on this subject based on the ideXlab platform.

  • correlations between the in vitro and in vivo bioactivity of the ti ha composites fabricated by a Powder Metallurgy Method
    Acta Biomaterialia, 2008
    Co-Authors: Congqin Ning, Yu Zhou
    Abstract:

    Abstract Ti/HA composites were successfully prepared by a Powder Metallurgy Method and the effect of phase composition on the in vitro and in vivo bioactivity of the Ti/HA composites was investigated in the present study. The correlations between the in vitro and in vivo biological behaviors were highlighted. The results showed that the in vitro and in vivo bioactivity of the Ti/HA composites was dependent on their phase composition. The in vitro bioactivity of the Ti/HA composites was evaluated in simulated body fluid with ion concentrations similar to those of human plasma. After immersion in the simulated body fluid for a certain time, apatite precipitations formed on the surface of the composites with an initial titanium content of 50 and 70 wt.%, and no apatite was found on the surface of the composite with 30% titanium. Ti 2 O was responsible for the apatite formation on the surfaces of the composites. For in vivo analysis, Ti/HA cylinders were implanted in the metaphases of the rabbit femur. At the early stage of implantation, the new bone formed on the surface of the composite with 30% titanium was much less than that on the surfaces of the composites with 50% and 70% titanium. All the Ti/HA composites formed a chemical bone-bonding interface with the host bone by 6 months after implantation. The Ti/HA composites formed the bone-bonding interface with the surrounding bone through an apatite layer. The results in the present study suggested that the in vivo results agreed well with the in vitro results.

  • in vitro bioactivity of a biocomposite fabricated from ha and ti Powders by Powder Metallurgy Method
    Biomaterials, 2002
    Co-Authors: C Q Ning, Yu Zhou
    Abstract:

    Traditionally, hydroxyapatite was used as a coating material on titanium substrate by various techniques. In the present work, a biocomposite was successfully fabricated from hydroxyapatite and titanium Powders by Powder Metallurgy Method. Bioactivity of the composite in a simulated body fluid (SBF) was investigated. Main crystal phases of the as-fabricated composite are found to be Ti2O, CaTiO3, CaO, a-Ti and a TiP-like phase. When the composite is immersed in the simulated body fluid for a certain time, a poor-crystallized, calcium-deficient, carbonate-containing apatite film will form on the surface of the composite. The time required to induce apatite nucleation is within 2 h. In addition, the apatite is also incorporated with a little magnesium and chlorine element. It is found that Ti2O has the ability to induce the formation of bone-like apatite in the SBF. And a dissolve of the CaO phase could also provide favorable conditions for the apatite formation, by forming open pores on the surface of the composite and increasing the degree of supersaturation of the SBF with respect to the apatite. r 2002 Elsevier Science Ltd. All rights reserved.

Muhammad Rashad - One of the best experts on this subject based on the ideXlab platform.

  • Room temperature mechanical properties of Mg–Cu–Al alloys synthesized using Powder Metallurgy Method
    Materials Science and Engineering A-structural Materials Properties Microstructure and Processing, 2015
    Co-Authors: Muhammad Rashad, Muhammad Asif
    Abstract:

    Abstract Conventional Powder Metallurgy Method was used to fabricate Mg–1Cu– x Al ( x =1 wt%, 3 wt%, 6 wt%, 9 wt%) alloys to study the influence of copper and aluminum on mechanical behavior of pure magnesium. Microstructural evaluation revealed the presence of Mg 17 Al 12 and Mg 2 Cu intermetallic phases in synthesized alloys. Experimental results exhibited that the increase in aluminum content lead to increase in Vickers hardness, 0.2% yield strength and ultimate strength (both in tension and compression). The tensile failure strain of alloys increases till the threshold of 3 wt% Al is reached. The decline in failure strain for the alloys containing higher wt% Al contents (i.e., 6 and 9 wt% Al), might be attributed to the formation of brittle intermetallic phase Mg 17 Al 12 .

  • Enhanced ductility of Mg–3Al–1Zn alloy reinforced with short length multi-walled carbon nanotubes using a Powder Metallurgy Method
    Progress in Natural Science: Materials International, 2015
    Co-Authors: Muhammad Rashad, Muhammad Asif, Li Li
    Abstract:

    Abstract Mg–3Al–1Zn–CNTs composites, with different weight fractions (0.25–1.0 wt%) of carbon nanotubes (CNTs) were successfully fabricated via a Powder Metallurgy Method. The processing parameters were adopted in such a way to have uniform dispersion of short length CNTs without any damage, as well as refined and dissolved β phases structures throughout the composite matrix. The composite exhibited impressive increase in microhardness (about +23%) and tensile failure strain value (about +98%) without significant compromise in tensile strength, compared to the un-reinforced Mg–3Al–1Zn alloy. The synthesized composites can be used in automotive and aerospace industries due to their low density and high specific strength.

  • improved strength and ductility of magnesium with addition of aluminum and graphene nanoplatelets al gnps using semi Powder Metallurgy Method
    Journal of Industrial and Engineering Chemistry, 2015
    Co-Authors: Muhammad Rashad, Muhammad Asif, Aitao Tang, Shahid Hussain
    Abstract:

    Abstract The Mg–Al–graphene nanoplatelets (GNPs) nano-composites were synthesized using the Powder Metallurgy Method. The effect of Al–GNPs hybrids addition in to pure Mg was examined through tensile and Vicker hardness tests. The GNPs content was kept constant (0.18 wt.%) and Al content was varied from 0.5 wt.% to 1.5 wt.%. The increase in Al content led to increase in 0.2%YS, UTS and failure strain (%). However for Al content exceeding over 1 wt.%, the failure strain(%) started to decrease. The best improvement was achieved with 1 wt.% Al (Mg–1.0Al–0.18GNPs). Mechanical strength of synthesized composites proved to be better than Mg–Al–CNTs and Mg–ceramic composites.

  • Improved strength and ductility of magnesium with addition of aluminum and graphene nanoplatelets (Al + GNPs) using semi Powder Metallurgy Method
    Journal of Industrial and Engineering Chemistry, 2015
    Co-Authors: Muhammad Rashad, Muhammad Asif, Aitao Tang, Shahid Hussain
    Abstract:

    Abstract The Mg–Al–graphene nanoplatelets (GNPs) nano-composites were synthesized using the Powder Metallurgy Method. The effect of Al–GNPs hybrids addition in to pure Mg was examined through tensile and Vicker hardness tests. The GNPs content was kept constant (0.18 wt.%) and Al content was varied from 0.5 wt.% to 1.5 wt.%. The increase in Al content led to increase in 0.2%YS, UTS and failure strain (%). However for Al content exceeding over 1 wt.%, the failure strain(%) started to decrease. The best improvement was achieved with 1 wt.% Al (Mg–1.0Al–0.18GNPs). Mechanical strength of synthesized composites proved to be better than Mg–Al–CNTs and Mg–ceramic composites.

  • Powder Metallurgy of mg 1 al 1 sn alloy reinforced with low content of graphene nanoplatelets gnps
    Journal of Industrial and Engineering Chemistry, 2014
    Co-Authors: Muhammad Rashad, Muhammad Asif, Aitao Tang
    Abstract:

    Abstract The Mg–1%Al–1%Sn–0.18% graphene nanoplatelets (GNPs) composite is fabricated by semi Powder Metallurgy Method followed by hot extrusion. Microscopic observation revealed the uniform distribution of GNPs in the matrix. The addition of 0.18 wt% GNPs to Mg–1wt%Al–1wt%Sn alloy lead to increase in tensile strength (i.e., from 236 to 269 MPa). The increase in strength of the composite could be due to high specific surface area, superior nano-filler adhesion and two-dimensional structure of GNPs.

Muhammad Asif - One of the best experts on this subject based on the ideXlab platform.

  • Room temperature mechanical properties of Mg–Cu–Al alloys synthesized using Powder Metallurgy Method
    Materials Science and Engineering A-structural Materials Properties Microstructure and Processing, 2015
    Co-Authors: Muhammad Rashad, Muhammad Asif
    Abstract:

    Abstract Conventional Powder Metallurgy Method was used to fabricate Mg–1Cu– x Al ( x =1 wt%, 3 wt%, 6 wt%, 9 wt%) alloys to study the influence of copper and aluminum on mechanical behavior of pure magnesium. Microstructural evaluation revealed the presence of Mg 17 Al 12 and Mg 2 Cu intermetallic phases in synthesized alloys. Experimental results exhibited that the increase in aluminum content lead to increase in Vickers hardness, 0.2% yield strength and ultimate strength (both in tension and compression). The tensile failure strain of alloys increases till the threshold of 3 wt% Al is reached. The decline in failure strain for the alloys containing higher wt% Al contents (i.e., 6 and 9 wt% Al), might be attributed to the formation of brittle intermetallic phase Mg 17 Al 12 .

  • Enhanced ductility of Mg–3Al–1Zn alloy reinforced with short length multi-walled carbon nanotubes using a Powder Metallurgy Method
    Progress in Natural Science: Materials International, 2015
    Co-Authors: Muhammad Rashad, Muhammad Asif, Li Li
    Abstract:

    Abstract Mg–3Al–1Zn–CNTs composites, with different weight fractions (0.25–1.0 wt%) of carbon nanotubes (CNTs) were successfully fabricated via a Powder Metallurgy Method. The processing parameters were adopted in such a way to have uniform dispersion of short length CNTs without any damage, as well as refined and dissolved β phases structures throughout the composite matrix. The composite exhibited impressive increase in microhardness (about +23%) and tensile failure strain value (about +98%) without significant compromise in tensile strength, compared to the un-reinforced Mg–3Al–1Zn alloy. The synthesized composites can be used in automotive and aerospace industries due to their low density and high specific strength.

  • improved strength and ductility of magnesium with addition of aluminum and graphene nanoplatelets al gnps using semi Powder Metallurgy Method
    Journal of Industrial and Engineering Chemistry, 2015
    Co-Authors: Muhammad Rashad, Muhammad Asif, Aitao Tang, Shahid Hussain
    Abstract:

    Abstract The Mg–Al–graphene nanoplatelets (GNPs) nano-composites were synthesized using the Powder Metallurgy Method. The effect of Al–GNPs hybrids addition in to pure Mg was examined through tensile and Vicker hardness tests. The GNPs content was kept constant (0.18 wt.%) and Al content was varied from 0.5 wt.% to 1.5 wt.%. The increase in Al content led to increase in 0.2%YS, UTS and failure strain (%). However for Al content exceeding over 1 wt.%, the failure strain(%) started to decrease. The best improvement was achieved with 1 wt.% Al (Mg–1.0Al–0.18GNPs). Mechanical strength of synthesized composites proved to be better than Mg–Al–CNTs and Mg–ceramic composites.

  • Improved strength and ductility of magnesium with addition of aluminum and graphene nanoplatelets (Al + GNPs) using semi Powder Metallurgy Method
    Journal of Industrial and Engineering Chemistry, 2015
    Co-Authors: Muhammad Rashad, Muhammad Asif, Aitao Tang, Shahid Hussain
    Abstract:

    Abstract The Mg–Al–graphene nanoplatelets (GNPs) nano-composites were synthesized using the Powder Metallurgy Method. The effect of Al–GNPs hybrids addition in to pure Mg was examined through tensile and Vicker hardness tests. The GNPs content was kept constant (0.18 wt.%) and Al content was varied from 0.5 wt.% to 1.5 wt.%. The increase in Al content led to increase in 0.2%YS, UTS and failure strain (%). However for Al content exceeding over 1 wt.%, the failure strain(%) started to decrease. The best improvement was achieved with 1 wt.% Al (Mg–1.0Al–0.18GNPs). Mechanical strength of synthesized composites proved to be better than Mg–Al–CNTs and Mg–ceramic composites.

  • Powder Metallurgy of mg 1 al 1 sn alloy reinforced with low content of graphene nanoplatelets gnps
    Journal of Industrial and Engineering Chemistry, 2014
    Co-Authors: Muhammad Rashad, Muhammad Asif, Aitao Tang
    Abstract:

    Abstract The Mg–1%Al–1%Sn–0.18% graphene nanoplatelets (GNPs) composite is fabricated by semi Powder Metallurgy Method followed by hot extrusion. Microscopic observation revealed the uniform distribution of GNPs in the matrix. The addition of 0.18 wt% GNPs to Mg–1wt%Al–1wt%Sn alloy lead to increase in tensile strength (i.e., from 236 to 269 MPa). The increase in strength of the composite could be due to high specific surface area, superior nano-filler adhesion and two-dimensional structure of GNPs.

Aitao Tang - One of the best experts on this subject based on the ideXlab platform.

Congqin Ning - One of the best experts on this subject based on the ideXlab platform.

  • correlations between the in vitro and in vivo bioactivity of the ti ha composites fabricated by a Powder Metallurgy Method
    Acta Biomaterialia, 2008
    Co-Authors: Congqin Ning, Yu Zhou
    Abstract:

    Abstract Ti/HA composites were successfully prepared by a Powder Metallurgy Method and the effect of phase composition on the in vitro and in vivo bioactivity of the Ti/HA composites was investigated in the present study. The correlations between the in vitro and in vivo biological behaviors were highlighted. The results showed that the in vitro and in vivo bioactivity of the Ti/HA composites was dependent on their phase composition. The in vitro bioactivity of the Ti/HA composites was evaluated in simulated body fluid with ion concentrations similar to those of human plasma. After immersion in the simulated body fluid for a certain time, apatite precipitations formed on the surface of the composites with an initial titanium content of 50 and 70 wt.%, and no apatite was found on the surface of the composite with 30% titanium. Ti 2 O was responsible for the apatite formation on the surfaces of the composites. For in vivo analysis, Ti/HA cylinders were implanted in the metaphases of the rabbit femur. At the early stage of implantation, the new bone formed on the surface of the composite with 30% titanium was much less than that on the surfaces of the composites with 50% and 70% titanium. All the Ti/HA composites formed a chemical bone-bonding interface with the host bone by 6 months after implantation. The Ti/HA composites formed the bone-bonding interface with the surrounding bone through an apatite layer. The results in the present study suggested that the in vivo results agreed well with the in vitro results.