TEM examination proves that the second phase particle within the as-forged Ti-55alloy consists of either bright or dark 'matrix' (nano-Nd3Sn) and some small dark blocks (SnO) dispersed in the 'matrix'...TEM examination proves that the second phase particle within the as-forged Ti-55alloy consists of either bright or dark 'matrix' (nano-Nd3Sn) and some small dark blocks (SnO) dispersed in the 'matrix'. The HREM observation shows that the nanoNd3Sn phase is roughly spherical and about 3-15nm in diameter, and the grain boundaries with atout 1nm width are 'gas-like' structure.展开更多
High resolution electron microscopy studies of rure earth-rich phase particles in a melt-quenched Ti-5Al-4Sn-2Zr-1MO-0.25Si-1Nd alloy indicate that the α-Ti matrix crystallizes prior to the rare earth-rich phase part...High resolution electron microscopy studies of rure earth-rich phase particles in a melt-quenched Ti-5Al-4Sn-2Zr-1MO-0.25Si-1Nd alloy indicate that the α-Ti matrix crystallizes prior to the rare earth-rich phase particles. According to a new nucleation model, the heteropeneous nucleation of the rare earth-rich phase particles at the matrix interface is easier than the homogeneous nucleation off the interface matrix, which is consistent with the results of the HREM obseroations.展开更多
The Ti-35V-15Cr-0.05C (wt% is a new nonburning titanium alloy. The test for alloy combustibility was carried out by using CO2 laser. A 430 watt and 6mm diameter laser spot impinges directly on the sample within normal...The Ti-35V-15Cr-0.05C (wt% is a new nonburning titanium alloy. The test for alloy combustibility was carried out by using CO2 laser. A 430 watt and 6mm diameter laser spot impinges directly on the sample within normal atmospheric pressure and temperature. The results show that the ignition time of the nonburning titanium alloy is the longest in the eight examined titanium alloys, and is 3.5 times that of TC4 alloy. The ignition tempeerature of the nonburning alloy is 2991° C, and is higher than that of TC4 alloy by 1976°C. On the condition of high tempeerature and rich oxygen,the surface of alloy forms a melting layer which plays roles of oxygen insulation, heat insulation and burning products insulation. This is the mechanism of combustion resistance.展开更多
文摘TEM examination proves that the second phase particle within the as-forged Ti-55alloy consists of either bright or dark 'matrix' (nano-Nd3Sn) and some small dark blocks (SnO) dispersed in the 'matrix'. The HREM observation shows that the nanoNd3Sn phase is roughly spherical and about 3-15nm in diameter, and the grain boundaries with atout 1nm width are 'gas-like' structure.
文摘High resolution electron microscopy studies of rure earth-rich phase particles in a melt-quenched Ti-5Al-4Sn-2Zr-1MO-0.25Si-1Nd alloy indicate that the α-Ti matrix crystallizes prior to the rare earth-rich phase particles. According to a new nucleation model, the heteropeneous nucleation of the rare earth-rich phase particles at the matrix interface is easier than the homogeneous nucleation off the interface matrix, which is consistent with the results of the HREM obseroations.
文摘The Ti-35V-15Cr-0.05C (wt% is a new nonburning titanium alloy. The test for alloy combustibility was carried out by using CO2 laser. A 430 watt and 6mm diameter laser spot impinges directly on the sample within normal atmospheric pressure and temperature. The results show that the ignition time of the nonburning titanium alloy is the longest in the eight examined titanium alloys, and is 3.5 times that of TC4 alloy. The ignition tempeerature of the nonburning alloy is 2991° C, and is higher than that of TC4 alloy by 1976°C. On the condition of high tempeerature and rich oxygen,the surface of alloy forms a melting layer which plays roles of oxygen insulation, heat insulation and burning products insulation. This is the mechanism of combustion resistance.
