2/MoSi2復(fù)合涂層。利用X射線衍射、掃描電子顯微鏡、能譜儀和熱力學(xué)計算對涂層進(jìn)行了表征與反應(yīng)機(jī)理分析。結(jié)果表明，共沉積法無法實現(xiàn)Ti的有效沉積。先滲Ti、再滲Si的兩步沉積工藝能有效制備Ti改性硅化物涂層。涂層分為3層，最外層為(Ti，Mo)Si2三元化合物層，次外層為MoSi2層，次外層與基體間為Mo5Si3過渡層。滲硅溫度對涂層結(jié)構(gòu)無明顯影響。Ti改性硅化物涂層的生長速率略低于單一滲硅涂層的生長速率。(Ti，Mo)Si2/MoSi2復(fù)合涂層的形成由Ti、Si內(nèi)擴(kuò)散控制。Ti元素集中在涂層表層，Si元素通過(Ti，Mo)Si2化合物層與基體作用形成MoSi2層和Mo5Si3過渡層。滲Ti過程中，埋滲料間反應(yīng)會引入游離態(tài)鋁氟化物AlF3。在隨后的滲硅過程中，游離態(tài)Al以Al3Mo的形式在(Ti，Mo)Si2層中靠近MoSi2層的上界面處析出。在1200 ℃周期性氧化過程中，(Ti，Mo)Si2/MoSi2復(fù)合涂層持續(xù)循環(huán)氧化180 h后未出現(xiàn)明顯失重。(Ti，Mo)Si2層氧化形成的SiO2與TiO2致密復(fù)合氧化層能填充涂層表面裂紋，持續(xù)阻礙氧擴(kuò)散，因此其在周期性氧化環(huán)境下的抗氧化性能顯著優(yōu)于單一滲硅涂層。;(Ti, Mo)Si2/MoSi2 composite coatings were prepared on Mo substrate by the continuous deposition pack cementation method. The X-ray diffraction (XRD), scanning electron microscope (SEM), energy dispersive spectroscopy (EDS), and thermody-namic calculation were used to characterize the composite coatings and to analyze the formation mechanism. The results show that the co-deposition process cannot achieve the titanium deposition effectively. The titanium-modified MoSi2 coatings can be prepared by a two-step deposition process of titanizing and siliconizing. The coatings contain three layers: the outer layer is (Ti, Mo)Si2 ternary compound layer; the second layer is MoSi2 layer; the layer between the MoSi2 and Mo substrate is the Mo5Si3 transition layer. The siliconizing temperature shows negligible effect on coating structure. The growth rate of titanium-modified MoSi2 coating is slightly lower than that of single MoSi2 coating. The growth of (Ti, Mo)Si2/MoSi2 composite coating is dominated by the inward diffusion of Ti and Si. Ti is concentrated on the outer layer of the coating. Si diffuses through the (Ti, Mo)Si2 compound layer and interacts with the substrate to form the MoSi2 layer and Mo5Si3 transition layer. In the titanizing process, the free state AlF3 is introduced by the reaction among pack mixtures. In the subsequent siliconizing process, a trace amount of Al in free state is precipitated in the form of Al3Mo phases in the (Ti, Mo)Si2 layer near the upper interface of MoSi2 layer. During the cyclic oxidation tests at 1200 °C, the (Ti, Mo)Si2/MoSi2 composite coatings do not lose mass obviously after exposure in oxidation atmosphere for 180 h. A dense composite oxide layer consisting of SiO2 and TiO2 can be formed by the oxidation of (Ti, Mo)Si2 phase. This composite oxide layer can fill the surface cracks of the coating and continuously block the oxygen diffusion, so the oxidation resistance of (Ti, Mo)Si2/MoSi2 composite coating in the periodic oxidation environment is far superior to that of the single MoSi2 coating."/>