The thermodynamic driving force for rapid crystallization of liquid metals, i.e.the Gibbs free energy difference △G_(LS) between undercooled liquid phase and product solid phase, is of essential importance for deepened investigations on rapid solidification such as the calculation of nucleation rate and the prediction of the formability of metastable phases as well as the feasibility of glass transition. An ultra-high-vacuum containerless processing technique by RF electromagnetic levitation melting was applied to undercoolliquid Fe and Ni by amounts up to 200 and 235 K. Specific heats of undercooled liquid Fe and Ni were measured by drop calorimetry and determined as. 48. 6 and 40. 5 J . mol~(-1) . K~(-1) respectively. On the basis of specific heat measurements, the △G_LS values of Fe and Ni were calculated according to its rigorous expression. Meanwhile, the theoretical models by Turnbull and Dubey-Ramachandrarao were also used to calculate the thermodynamic driving force approximately. It was found that Dubey-Ramachandrarao model usually showed smaller deviations but both models deviated significantly from the rigorous calculations provided that the undercooling exceeded 100 K. Since the deviation of approximated △G_(LS) value has a drastic influence on the calculation of nucleation rate in the undercooled liquid metals, it is necessary to do rigorous calculations about the thermodynamic driving force for any quantitative research on rapid crystallization.

Gas-atomized spray deposition(SD) process is used for the manufacture of rapidly solidified bulk and near-net-shape preforms. The mass, momentum and energy transfers of the gas and the atomized droplets during atomization have great influence on the microstructures and properties of the deposit. The flow behaviour of the gas and the droplets are studied based on the mass, momentum and energy conservation theory. The mathematical model of the three-dimensional flow of the gas and droplets is proposed, and the controlling equations of the flow are deduced.

Phase diagram of KF-LiCl-CaCl_2 system has been determined by methods of visual variable-temperature, DTA and XRD. A negative deviation for KF occurs in molten salt LiCl-CaCl_2 solution. The semi-quantitative relationship between the relative area of primary crystallization region for fluoride of divalent alkaline metal and the energetic parameter of solution was also discussed together with KF-LiCl-BaCl_2 and KF-LiCl-SrCl_2 systems made previously by the authors.

By use of XRD and TEM, structure of the crystalliztion products of amorphous Fe_(80)B_(20)alloy with different regimes of heat treatment was studied. The crystallization products are composed of α-Fe(B) solution and Fe-B compound. The relative quantity of the α- Fe solid solution phase increases with the annealing temperature. The compound phases, Fe_3B and Fe_(3.5)B, change in relative quantity also with heat treatment. The lattice distortion of the crystallization products was detected.

Effect of temperature and strain rate on superplasticity of Ti-24Al-14Nb-3V-0.5Mo alloy has been studied. Under the optimal condition of 980℃ and 3.5 ×10~(-4)s~(-1), the maximum values of the strain rate sensitivity index, m, and tensile elongation are 0.69 and 818% respectively. A fine equiaxed α_2+β_0 duplex structure was observed in the superplastically deformed alloy. Together with the behaviour of alloy under isothermal tension test,it is believed that the alloy is of the fine-grained structural superplasticity. During superplastical deformation. no cavitation was found, but dynamic coarsening of the microstructure occurred .

The TiC reinforced Al composite was prepared by in-situ contact-reaction.The TiC particles are sized down to nm, and free from lattice defect practically. No interaction between TiC and α-Al interfaces was found. The composite, thus, has a superior properties as comparison with that of pure Al.

Synthesis of TiC films was investigated by dual ion beam deposition. Higher Knoop hardness number on the TiC films prepared by CH_4 ion beam enhanced deposition as comparison with that without CH_4 was obtained. The important reason, which showed by XPS, TEM and AES analyses, may be due to the excess C introduced to the TiC films during ion beam bombardment.

XPS, AES and XRD show that the main composition of TiN film prepared by ion beam assisted deposition is TiN with fine grain size and slightly preferential orientation,except predominent TiO_2 on surface of film and a wide mixed region of Ti, Fe, N at interface between film and substrate. The tribological behaviour of the TiN film was tested on a ball/disc frictional device under stepwise loading and lubricating sliding. From P-v diagram, the enlargement of boundary lubrication region has been found. It seems that the existence of TiN film increases the load carrying capacity of substrate of Cr12MoV steel.

Based on Fick's law, the kinetic expression considering the variance of interdiffusion coefficients in Fe-Al-C system with AI concentration was derived for estimating the AI degeneration of aluminized layer on steel undergone high temperature oxidation. The calculated values obtained were in fair agreement with the measured ones by experiments.

The composition and structure of the different phases in the Sm-Fe-N alloy as well as the phase transformation during ion-nitrizing have been studied. The magnetic phase Sm_2Fe_(17)N_x transformed into the amorphous during ion-nitrizing, moreover, partially resolved into SmFe_3N_x and α－Fe.