| Casting sintering is a new technique by which iron-based surface composites are produced. Based on the characteristics of the technique, combustion behaviors of the composite layer of an iron-based surface composite reinforced by TiC under the conditions of the liquid forming were studied in the paper. And combustion behaviors of Fe-Ti-C systems under a thermal or an electric field were also studied. The technique is new as a method to produce a surface composite, so there is still lack of fundamental study. As the reason, the study is the work with significant value in practice and theory. In the paper, the combustion behavior of a composite layer under the conditions of liquid forming was studied. By using samples with different shapes, effect of metal liquids and composition of a composite layer on the combustion behavior was investigated. The characteristics of ignition and combustion transmission were analyzed. The results show that under the thermal field, activation of a reaction inside the composite layer depends on the pouring temperature of liquid metal and on thermal strike intensity of liquid metal upon the composite layer. The reaction in the layer can be activated by iron liquid, and can not be activated by aluminum liquid. The ignition process has the characteristic of thermal plate ignition. The delayed time of ignition is controlled by the compositions of the layers and heat exchange in the process of liquid forming, especially by unreacting component of the system. When the reaction happens in the layer, the temperature of liquid metal rises suddenly due to the heat released by the reaction inside the layer, and the direction of heat flow in the layer changes at this time, which means that liquid metal has absorbed a lot of the heat. It is existence of unreacting component and heat exchange that make it difficult combustion in the layers to continue and reaction to transfer. As the result, the reaction is easily terminated, which leads to the combustion not to finish. For the reason, the only way to produce surface composites free from defects is to control the thickness of a composite layer and technological conditions firmly.For further study on the combustion behaviors of Fe-Ti-C systems, thermal simulation experiments were carried out by using thermal simulating apparatus, Gleeble-1500D. During the thermal simulation experiments, a sample is heated by application of an electric field. Based on process control by the instrument, effects of compositions and other conditions on combustion behaviors of systems were studied by using the instrument. The results show that under the action of an electric field, combustion reactions of Fe-Ti-C systems can be activated, and their starting temperatures of reactions are rather low, compared with those in other combustion processes. It is amazing that the reaction can occur when the pre-heating temperature is only 430℃. It is clear that low-temperature combustion synthesis of the system under the action of an electric field is one of the most important characteristics of the combustion behaviors, which is also one of the most important achievements of the research. When the reaction occurs, shrinkage of a sample occurs at the same time. The results also show that the combustion behaviors were controlled by compositions of samples, pre-heating temperature and pre-heating rate. When the heating conditions are same, the starting temperature of combustion reactions goes up as increase of Fe content. At this situation, combustion mode will change, and dependence on outer energy during combustion process increases and stability of the combustion becomes weak. When pre-heating temperature increases, starting combustion temperature decreases, which means that the pre-heating temperature is a necessary condition for a combustion reaction. The results give the points that the pre-heating rate has more significant effect on the combustion behaviors of systems than the others. With increase of the pre-heating rate, starting combustion temperat...
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