Spray forming technology for military applications

1994 ◽  
Vol 3 (2) ◽  
pp. 197-198 ◽  
Author(s):  
A. Moran ◽  
C. Madden ◽  
R. Rebis ◽  
R. Payne ◽  
M. A. Matteson
2015 ◽  
Vol 645-646 ◽  
pp. 246-251
Author(s):  
Hai Tao Gao ◽  
Jian Jiang Wang ◽  
Hong Fei Lou ◽  
Xu Dong Cai ◽  
Yong Shen Hou

Fe+MnO +Fe2O3+ZnO reaction system was used to prepare Mn-Zn ferrite flake absorbent by self-reactive spray forming technology. Extrinsic enthalpy (H) and adiabatic temperature (Tad) of system were calculated. The formation mechanism and electromagnetic properties of Mn-Zn ferrite flake absorbent were analyzed. The results show that Tad exceeded 1998K, self-propagation reaction can be ignited and products can be melted. The droplets impacted onto copperplate to achieve flake shape. SEM and XRD were used to characterize the morphology and phase of samples. The results show that most of flake absorbent are at 100μm wide and 10μm thick, and they are constituted by pure Mn0.5Zn0.5Fe2O4 phase with spinel crystal structure. Absorption test show that the absorbent has two absorption peaks, the minimum value of reflectivity is at -27dB and the bandwidth lower than -10dB reaches to 3.5GHz. The Mn-Zn ferrite flake absorbent provides with preferable properties, which is potential in the further investigations.


2011 ◽  
Vol 117-119 ◽  
pp. 1447-1452
Author(s):  
Guo Wei Zhang ◽  
Zheng Chen ◽  
Wei Chen ◽  
Hai Ying Xin ◽  
Jing Zhai ◽  
...  

The Mg-9Al-3Zn-0.6Mn-xNd alloys, preformed with φ300mm size, has been prepared by spray forming technology under a protective atmosphere. The microstructure and mechanical properties have been investigated by XRD, scanning electron microscopy (SEM), transmission electron microscopy (TEM) and strengths tested mechine. As a result, the precipitate phases in the alloys were the finest when the Nd content was 1% compared the alloys with the Nd content were 2% and 3%, the size of precipitation phases are between 1-2um and there are phases like Mg2Ca,Al2Ca,and MgZn2in the alloys. After extrusion, recrystallization microstructures were found in the alloys. The tensile strengths are between 400-450MPa and the yield strengths are between 350-370MPa respectively as the differences content of Nd in the alloys after heat treatment.


2003 ◽  
Vol 138 (1-3) ◽  
pp. 357-360 ◽  
Author(s):  
Jing Guo Zhang ◽  
Hai Sheng Shi ◽  
De Sheng Sun

2005 ◽  
Vol 475-479 ◽  
pp. 2773-2778 ◽  
Author(s):  
Guo Qing Zhang ◽  
Zhou Li ◽  
Zhong Wu Liu ◽  
Zhi Hui Zhang ◽  
Yifei Zhang ◽  
...  

A unique pilot low-pressure spray forming plant was established and its spray atomisation and deposition process developed to study the new processing methods for high performance materials and to develop spray forming technology suitable for making sound superalloy preforms. The results indicated that high density (>99%) preforms (billets and rings) with little gas pick-ups and with the microstructural features of rapidly solidified superalloys, i.e. refined equiaxed grains and uniform microstructure, could be achieved after the optimisation of the spray atomisation and deposition process. The effects of subsequent thermal processing on the density, microstructure and mechanical properties of the spray formed superalloy were investigated. Compared to the turbine disks and rings made by wrought superalloys, the spray formed superalloys with identical chemistry showed significantly improved metallurgical quality, higher mechanical properties, and better hot workability.


2016 ◽  
Vol 1 (1) ◽  
pp. 168 ◽  
Author(s):  
L.L. Tang ◽  
Y.H. Zhao ◽  
R.K. Islamgaliev ◽  
R.Z. Valiev

<p>Fast spray forming technology followed by equal channel angular pressing (ECAP) was employed to obtain a specific microstructure: separated coarse magnesium grains surrounded by deformation networks. The deformation layer consisted of ultrafine grained magnesium with an average grain size of 0.6 μm and ellipsoidal shaped β-Mg<sub>17</sub>Al<sub>12</sub> particles with a size of 200-300 nm and a volume fraction of 13%. Mechanical tensile test demonstrates the advantage of the specific structure: a yield strength of 235MPa combined with an elongation to failure of 14%.</p>


2013 ◽  
Vol 744 ◽  
pp. 334-338
Author(s):  
Hong Wei Liu

Mechanical adhesion method and precursor method were used to prepare Ti-B4C-C and Ti-B4C-Sucrose composite powders respectively with Ti, B4C, graphite and sucrose (precursor of C) as raw materials. Ti (C,N)-TiB2 composite ceramic preforms were prepared with the two kinds of powders by self-reactive spray forming technology. The compositions and microstructure were analyzed and observed by means of XRD and SEM. The porosity and fracture toughness of the preforms were tested. Then the influence of powder preparation technology on the microstructure and properties of the preforms were contrastively analyzed. It was shown that compared with Ti-B4C-C composite powders, Ti-B4C-Sucrose composite powders had lower interior adhesive strength, but the different composition among them mixed more uniformly and contacted tighter, which made the SHS reaction of them during the spray forming process take place more sufficiently. The two kinds of preforms were both composed of Ti (C,N)-TiB2 main phases, titanium oxide by-product phases and some pores. Whereas there were less kinds and content of by-product phases in the preforms prepared with Ti-B4C-Sucrose powders, and the materials were uniform and dense, with higher fracture toughness. The general properties of the preforms were obviously better than that of the preforms prepared with Ti-B4C-C composite powders.


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