Some Aspects Regarding the Complex Alloying of the Ni3Al Intermetallic Compound with Substitutional and Interstitial Elements

2007 ◽  
Vol 23 ◽  
pp. 67-70 ◽  
Author(s):  
Mariana Lucaci ◽  
Radu L. Orban ◽  
Delia Patroi ◽  
S. Hodorogea ◽  
I. Bibicu ◽  
...  

Research results focussed on the combined influence of iron and boron, in proportions of 0.5 and up to 10 wt.% respectively, in complex alloyed Ni3Al synthesised by Self Propagating High Temperature Synthesis (SHS) in the thermo-explosion mode at two ignition temperatures, 950 and 1150 oC, are presented. By XRD and Mössbauer spectroscopy it was established that for 950 oC ignition temperature, the evolved heat is not high enough for the added Fe to be fully incorporated into the synthesised Ni3Al phase, a temperature of 1150 oC being required. For this temperature, the density of the synthesised alloys, their capacity to be cold deformed by re-pressing, hardness and bending strength variations as a function of B and Fe contents, proved their cumulative effects of the ductility and mechanical properties of complex alloyed Ni3Al enhancing.

2011 ◽  
Vol 239-242 ◽  
pp. 1072-1075
Author(s):  
Yu Xin Li ◽  
Pei Kang Bai

Ni/TiC composites have been produced using laser induced self-propagating high-temperature synthesis. The chemical composition and microstructure were investigated by means of X-ray diffraction and scanning electron microscope. The sintered density and mechanical properties such as bending strength and micro-hardness were also measured. The results showed that the synthesized products were consisted of TiC and Ni phases, which indicated that the TiC was synthesized by the in-situ reaction. Moreover, the results revealed that the sintered density increased and the micro-hardness and bending strength of the synthesized products gradually decreased with the increasing of Ni contents.


2014 ◽  
Vol 900 ◽  
pp. 141-145 ◽  
Author(s):  
Can Feng Fang ◽  
Guang Xu Liu ◽  
Ling Gang Meng ◽  
Xing Guo Zhang

The effects of in-situ TiB2 particle fabricated from Al-Ti-B system via the self-propagating high-temperature synthesis (SHS) reaction technology on microstructure and mechanical properties of Mg-Sn-Zn-Al alloy were investigated. The results indicate that the size of the Mg2Sn and α-Mg+Mg32(Al,Zn)49 phase becomes coarser with the increasing content of Al-Ti-B preform, meanwhile the amount of eutectic α-Mg+Mg32(Al,Zn)49 phase increases too. The addition of Al-Ti-B is favorable toward promoting the strength of composites, but deteriorates elongation. The resulting as-extruded composite material with 4 wt.% Al-Ti-B preform exhibits good overall mechanical properties with an ultimate tensile strength of 291 MPa and an elongation over 2 %.


2007 ◽  
Vol 546-549 ◽  
pp. 2179-2182 ◽  
Author(s):  
Ling Bai ◽  
Xing Yu Zhao ◽  
Chang Chun Ge

Sintering of the Self-Propagating High-Temperature Synthesis (SHS) of β-Si3N4 powder with 6.67 wt.% Y2O3 and 3.33 wt.% Al2O3 as sintering additives has been emphatically investigated using hot-press sintering process. The relative density of hot-pressed β-Si3N4 reached near to the full densification (99.43%) at 1700°C. The similar micrographs with self-reinforcing rod-like β-Si3N4 grains forming an interlocking structure were observed. The better mechanical properties of hot-pressed Si3N4, such as the hardness (16.73GPa), fracture toughness (5.72 MPa·m1/2) and bending strength (611.72MPa) values, were obtained at 1700°C. The results indicate that good sinter ability can be obtained with the cheaply SHS of silicon nitride powder for preparing silicon nitride materials, which will make the cost of silicon nitride materials lowered.


2013 ◽  
Vol 659 ◽  
pp. 10-14
Author(s):  
Yu Zhu ◽  
Feng Huang ◽  
Yu Xi Ge ◽  
Hong Jun Ni

In order to improve the density and mechanical properties of ceramic-lined composite steel pipes produced by Centrifugal Self-propagating High-temperature Synthesis. Composite steel pipes were prepared by the method of centrifugal-SHS on the basic of Al-Fe2O3 system. With the condition of adding 6% SiO2 and 4% Na2B4O7, the effect of different amount of nano-TiO2 on the density and the mechanical properties of composite steel pipes was studied. By means of SEM analysis, XRD and mechanical tests, the results show that the ceramic layer consists of main crystal phase of α-Al2O3, with small amount phases of FeAl2O4, Al2SiO5 and B2O3. The surface of ceramic layer is smooth, without obvious crack and with good density. The shearing strength of the ceramic layer and the crushing strength of the composite pipe were 13.5 MPa under 8% (in mass) nano-TiO2 and 525Mpa. The density of ceramic layer is up to 94.2% under 8% (in mass) nano-TiO2.


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