Study On Preparation And Compression Property Of Porous Titanium And Its Alloy

Owing to the rapid development of high-tech technology, the demands on the properties, structure and other aspects of material has gradually increased and simultaneously extended to the direction of light quantity and the combination of various advanced functional materials with admirable properties and structure materials in order to satisfy the different application demands of disparate field. Through optimize the parameter of the fabrication process and the structure of porous Ti matrix composites have been optimized so as to supply the theoretical foundation and basis to realize the fabrication of porous metal with splendid properties.In this paper, under the experimental condition of the vacuμm degree of 10-1 pa, the sintering temperature of 1250℃ and sintering time of 2h, the porous titanium is fabricated by powder metallurgy blend element method. The effect of the addition of Fe V80 and carbon powder along with the high-energy ball mill pretreatment of raw material on the porous structure, microstructure and compressive property have been studied. Then, the effect of porosity character of porous material on elastic modulus were studied by Comsol,. and compared with theoretical calculation by Nielsen model, the mechanical properties of porous materials have been assessed and predicted, the key conclusions are as follows:① The roughness on the surface and the particle size of the raw material that are mixed by the ratios of Ti-x C and Ti-x Fe V80 followed by the high-energy ball mill pretreatment for 60 minutes are added and thinned separately, and some raw material powders have the phenomenon of aggregation but no new phases generated.② The influences of different addition of carbon powder mixed with Ti powder and the employment of ball-milling technique on material structure and properties have been studied. The conclusions manifest that porosity has a decreasing trend with increase the addition of carbon, however, apparent increase in porosity when the addition of carbon is increasing to 2.5wt %. The phase of Ti C is generated in the matrix manifested from the detection results of XRD.③ The sintering compacts of porous Ti matrix composites fabricated by raw material through pretreatment present better density, the process of the coarsening and the particles combine much better. When the carbon content achieves 1.5wt% and 2.0 wt%, the initial yield strength reaches the highest with 339.8 MPa and 331.1 MPa separately and 1.5 wt% is a little lower than 2.0 wt%. When the content of carbon powder is achieve 2.5 wt%, the initial yield strength decrease to 195.1 MPa. When it comes to raw material that is not pretreated, the initial yield strength of the sample composed with pure Ti is 143.2 MPa and the initial yield strength reaches to 182.4 MPa when the addition of C is 1wt%. When the addition is increased to 2 wt% and 2.5 wt%, the strength decreased slightly with 176 MPa and 141.1MPa separately.④ The influences of different addition of carbon powder mixed with Ti powder and the employment of ball-milling technique on material structure and properties have been studied. The results show that appropriate addition of Fe V80 could improve the densification of the pore structure of the materials. The detection results of XRD manifest that new phases of TixVy(x+y=1) are formed in the matrix. After the pretreatment of the raw materials, the elastic modulus value of the sintering sample composed of pure Ti reaches to 184.7MPa. When the content of Fe V80 reaches 12wt% and 16wt%, the strength of the samples are 281.4MPa and 277.3MPa, a little decrease, respectively. When it comes to raw material that is not pretreated, the initial yield strength of the sample composed with pure Ti is 143.6MPa and the reaches to 201.8MPa when the addition of Fe V80 is 8wt%. When the addition is increased to 12wt% and 16wt%, the strength decreased slightly with 194.6MPa and 198.2MPa separately.⑤ The effect of different porous character on elastic modulus were calculate by Comsol, and compared with the calculate conclusion by Nielsen model. The results imply that the elastic modulus is decreasing from 30.77 GPa to 15.94 GPa as the porosity is increasing from 28.3% to 72.3%. The unknown number of Nielsen model n is 2.4 and the theoretical results are decreased from 49.05 GPa to 15.94 GPa. The same tendency indicates that the elastic modulus is decreased with increasing the porosity. When the shape factor and porosity is constant(P=1, v=0.5) and the pore sizes are increased form 0.1mm to 0.5mm, the elastic modulus value decreased from 26.39 GPa to 25.87 GPa. When the porosity is 50%, the shape factor decreases from 1 to 0.746, the modulus value decreases from 24.7GPa to 17.8GPa. At the same situation, the results of Nielsen indicate that the modulus value decreases from 20.6 GPa to 17.6 GPa。...