Effects of Y2O3 on Microstructure and Mechanical Properties of Laser Clad Coatings Reinforced by In Situ Synthesized TiB and TiC

2011 ◽  
Vol 675-677 ◽  
pp. 589-592 ◽  
Author(s):  
Jun Li ◽  
Zhi Shui Yu ◽  
Hui Ping Wang

Titanium-based coatings reinforced by in situ synthesized TiB and TiC were deposited on Ti6Al4V by laser cladding. The effects of Y2O3 on microstructure and mechanical properties of the coatings were investigated. The coating without Y2O3 is mainly composed of a-Ti cellular dendrites and an eutecticum in which a large number of coarse and fine needle-shaped TiB and a few equiaxial TiC particles are homogeneously embedded. A small amount of Y2O3 addition can refine the microstructure by transforming a-Ti grains from cellular dendrites to columnar or equiaxial crystals, and can increase the volume fraction of the reinforcements. The addition of Y2O3 can also increase microhardness and reduce the cracking sensitivity of the coating.

2013 ◽  
Vol 341-342 ◽  
pp. 162-165 ◽  
Author(s):  
Fang Zhou ◽  
Hui Yao Yang ◽  
Liang Hua He

A Fe-based composite coating reinforced with in situ synthesized TiC-TiB2particles was successfully fabricated on Q235A by laser cladding with mixture powder of TiO2, Al, B4C, C and Fe55 as precursors. The microstructure and mechanical properties of coating were investigated. The results show that the main phases of coating are TiB2, TiC, (Fe,Cr)7C3and α-Fe. TiC particles show the shape of block, TiB2particles exhibit the shape of strip. Compared with the Q235A, the microhardness of the composite coating improved drastically.


2010 ◽  
Vol 638-642 ◽  
pp. 1558-1561
Author(s):  
Dae Guen Kim ◽  
Jae Seol Lee ◽  
Seul Ki Park ◽  
Young Mo Kim ◽  
Hyeon Taek Son ◽  
...  

In the present work, the effect of Nd addition on microstructure change, precipitation behaviours and mechanical properties, of Mg-5Sn-3Ca based alloys were investigated. With increasing of Nd addition, size of the Mg-Sn-Ca ternary phases with fine needle shape (A-type) was decreased and volume fraction of these phase were increased. As Nd was increase from 0.5, 1.0 and 3.0 wt.%, size and volume fraction of Mg2Sn with coarse needle shape phase (B-type) was decreased. However, in 3.0 wt.% Nd containing alloy, size of these Mg2Sn phase was smaller than that of 0.5 and 1.0 wt% Nd addition alloy and volume fraction of these phase was decreased.


2021 ◽  
Vol 212 ◽  
pp. 108681
Author(s):  
Diqiang Liu ◽  
Aijun Zhang ◽  
Jiangang Jia ◽  
Jiesheng Han ◽  
Junyan Zhang ◽  
...  

Crystals ◽  
2021 ◽  
Vol 11 (4) ◽  
pp. 422
Author(s):  
Kuai Zhang ◽  
Yungang Li ◽  
Hongyan Yan ◽  
Chuang Wang ◽  
Hui Li ◽  
...  

An Fe/FeAl2O4 composite was prepared with Fe-Fe2O3-Al2O3 powder by a hot press sintering method. The mass ratio was 6:1:2, sintering pressure was 30 MPa, and holding time was 120 min. The raw materials for the powder particles were respectively 1 µm (Fe), 0.5 µm (Fe2O3), and 1 µm (Al2O3) in diameter. The effect of sintering temperature on the microstructure and mechanical properties of Fe/FeAl2O4 composite was studied. The results showed that Fe/FeAl2O4 composite was formed by in situ reaction at 1300 °C–1500 °C. With the increased sintering temperature, the microstructure and mechanical properties of the Fe/FeAl2O4 composite showed a change law that initially became better and then became worse. The best microstructure and optimal mechanical properties were obtained at 1400 °C. At this temperature, the grain size of Fe and FeAl2O4 phases in Fe/FeAl2O4 composite was uniform, the relative density was 96.7%, and the Vickers hardness and bending strength were 1.88 GPa and 280.0 MPa, respectively. The wettability between Fe and FeAl2O4 was enhanced with increased sintering temperature. And then the densification process was accelerated. Finally, the microstructure and mechanical properties of the Fe/FeAl2O4 composite were improved.


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