(中南大學(xué) 輕質(zhì)高強(qiáng)結(jié)構(gòu)材料國(guó)家級(jí)重點(diǎn)實(shí)驗(yàn)室，長(zhǎng)沙 410083)
摘 要: 以高純鎢粉和高純X粉為原料，通過放電等離子燒結(jié)技術(shù) (SPS)制備了不同X含量的W-X合金材料，并結(jié)合X射線衍射儀、掃描電鏡、透射電鏡等分析手段，研究X含量對(duì)W-X合金材料微觀組織及強(qiáng)韌性的影響。結(jié)果表明：W-X合金材料的主要相組成為W-X固溶體和X的氧化產(chǎn)物X2O5；X元素的加入改變了純鎢的變形機(jī)制，在螺位錯(cuò)的基礎(chǔ)上，出現(xiàn)了刃位錯(cuò)；隨著X含量的增加，X固溶到鎢晶粒中的比例逐漸增大，晶粒尺寸發(fā)生長(zhǎng)大；隨著X含量的增加，W-X合金材料的相對(duì)密度先增加后趨于穩(wěn)定，壓縮強(qiáng)度呈現(xiàn)先增大后減小的規(guī)律；當(dāng)X含量為30%(質(zhì)量分?jǐn)?shù))時(shí)，W-X合金呈現(xiàn)最佳性能，壓縮強(qiáng)度達(dá)2044 MPa，壓縮應(yīng)變達(dá)24%。
關(guān)鍵字: 高強(qiáng)；高韌；鎢；固溶體；放電等離子燒結(jié)
（National Key Laboratory of Science and Technology for National Defence on High-strength Structural Materials, Central South University, Changsha 410083, China）
Abstract:W-X alloy was prepared by spark plasma sintering (SPS) with high purity tungsten powder and X powder. The effect of X content on the solid solution characteristics and strength and toughness of W-X alloy was studied by means of X-ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM) and energy dispersive spectroscopy (EDS). The results show that the main phases of the W-X alloy are W-X solid solution and X2O5. The addition of X changes the deformation mechanism of pure tungsten. On the basis of screw dislocation, the edge dislocations appear. The amount of X solid solution into tungsten grain increases gradually with the increase of X content. The grain size grows up with the increase of X content，which seriously reduces the mechanical properties of the W-X alloy. The relative density of the W-X alloy gradually increases with the increase of X content. The compressive strength of W-X alloy first increases and then decreases with the increase of X content. When the X content is 30% (mass fraction), the performance of W-X is the best, the compressive strength is 2044 MPa and the fracture strain is 24%.
Key words: high strength; high toughness; tungsten; solid solution; spark plasma sintering
