| In this paper, the powder and compact preparation, process parameters of sintering of particle reinforced titanium matrix composite were researched and analyzed. The preparation process as follow:the particle size was 30μm; the pressing technique of compact was 250MPa 2min moulding and 250MPa 2min moulding+300MPa 2min cold isostatic pressing; the pressing technique of sintering was vacuum sintering at 1350℃for 3h.The sintering samples with different content of Fe and Cr3C2 are prepared by this process.The experiment results of property test and microstructure were analyzed. The main conclusion as follow:1. The test result of XRD,SEM and EDS analysis forTi-1.6Fe-2.15Mo-(1.6Al-Nd)-4.5 Cr3C2 showed that the reaction between Ti and Cr3C2 generated after Cr3C2 was injected into Ti-Fe-Mo-(Nd-Al) matrix, and the product of this reaction was TiC and TiCr solid solution.2. The research showed that the relativity density of Ti-1.6Fe-2.15Mo-(1.6Al-Nd)-X Cr3C2 (X=0,4.5,8,13) increased first and then decreased with the content of Cr3C2 increased, its maximum was 98.26% when the content of Cr3C2 reached 4.5wt%,its pore small, uniform and smooth.3. The hardness of Ti-1.6Fe-2.15Mo-(1.6Al-Nd)-X Cr3C2(X=0,4.5,8,13) increased with the content of Cr3C2 increased. Its maximum was 56.7HRC with Owt% Cr3C2 content; its minimum was 58.2 with 13 wt% Cr3C2 content. The TRS of Ti-1.6Fe-2.15Mo-(1.6Al-Nd)-X Cr3C2(X=0,4.5,8,13) increased first and then decreased, its maximum was 1917MPa when the content of Cr3C2 reached 4.5%.4. The fractgraph anaysis showed that the micrograph of Ti-1.6Fe-2.15Mo-(1.6Al-Nd) X Cr3C2(X=0,4.5,8,13) were widmanstatten structure made of a+B phase, TiC hard-paticle on the base of network structure made of a+βphase, uniform and small TiC hard-paticle on the base of duplex structure made of a+βphase withβphase and a phase disconnected and rough TiC hard-paticle on the base ofβphase, when the content of Cr3C2 were 0wt%,4.5wt%,8wt% and 13wt% respectively. The feature of SEM fractograph of Ti-1.6Fe-2.15Mo-(1.6Al-Nd)-X Cr3C2(X=0,4.5,8,13)was tonguelike pattern and dimple with 4.5wt% Cr3C2 content whose fracture mode was quasi-clevage fracture and cleavage fracture: ductile fracture with 8wt% and 13wt% Cr3C2 content and the dimple of latter was big and dip than former.5. The relativity density of Ti-XFe-2.15Mo-(1.6Al-Nd)+4.5Cr3C2 (X=1.6,2.2,2.8,3.4) increased with the content of Fe increased, and its maximum was 99.58% when the content of Fe reached 3.4wt%;the hardness decreased with the content of Fe increased. The TRS increased first and then decreased, and its maximum was 3050MPa when the content of Fe reached 2.2wt% whose sintering sample prepared by moulding+ cold isostatic pressing.6. The micrograph of Ti-XFe-2.15Mo-(1.6Al-Nd)+4.5Cr3C2 (X=l.6,2.2,2.8,3.4) with content of Fe were 1.6wt%,2.2wt% and 2.8wt% was TiC hard-paticle on the base of a+βphase dispersedly and uniformly; and SEM micrograph showed that its grain size enlarged, the grain size ofβphase, a cluster and the siza of a layers increased too, when the content of Fe from 1.6wt% increased to 2.8wt%.The structure of base of alloy with 4.5wt% Fe content was the disconnected,primary a particle on the base of a+βphase. The SEM fractograph showed that their fracture mode was quasi-clevage fracture and cleavage fracture, existing river pattern and small dimple. The difference was that surface layers of fracture become bigger, larger and smoother, when the content of Fe increased. |
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