(哈爾濱工業(yè)大學(xué)材料科學(xué)與工程學(xué)院， 哈爾濱 150001)
摘 要: 在2000℃， 20MPa壓力下于1.3×10-3 Pa真空中熱壓燒結(jié)1h制備了含20%ZrC顆粒(體積分?jǐn)?shù))的鎢基復(fù)合材料。 組織觀察表明： ZrC顆粒比較均勻分布于W基體中， ZrC顆粒阻礙了W晶粒的長大， 也妨礙了材料的致密化；由于ZrCp/W界面處存在W及Zr元素的互擴(kuò)散， 得到了強(qiáng)的界面結(jié)合； 部分W原子擴(kuò)散到ZrC點(diǎn)陣中， 形成了(Zr, W)C固溶體； 隨著溫度提高， 復(fù)合材料的抗彎強(qiáng)度逐漸提高， 在800℃達(dá)到最大值1074MPa， 比室溫強(qiáng)度762MPa提高41%， 而后又隨溫度繼續(xù)上升而下降。 ZrCp/W復(fù)合材料這種好的高溫強(qiáng)度主要是由于W基體隨溫度上升發(fā)生了由脆性到塑性的轉(zhuǎn)變， 使ZrC顆粒增強(qiáng)效果在高溫得以充分發(fā)揮； 位錯強(qiáng)化、 載荷傳遞和裂紋釘扎是ZrCp/W復(fù)合材料的高溫強(qiáng)化機(jī)理。
關(guān)鍵字: 鎢基復(fù)合材料 ZrC顆粒 高溫強(qiáng)度 塑脆轉(zhuǎn)變
STRENGTH OF ZrCp/W COMPOSITES
（School of Materials Science and Engineering, Harbin Institute of Technology, Harbin 150001, P. R. China）
Abstract:Tungsten matrix composites containing 20% ZrC particles (volume fraction) was prepared by hot pressing at 2000℃, 20MPa in a vacuum of 1.3×10-3Pa for 1h. The results show that the ZrC particles are welldistributed within the W matrix, and the growth of W grains is prevented by the ZrC particles during sintering; there is an interdiffusion of Zr and W in ZrCp/W interface, which results in a strong bond; a (Zr, W)C solid solution zone is formed in ZrC. As the temperature increased, the bending strength of ZrCp/W composites increases gradually and reaches its maximum value 1074MPa at 800℃, which is 41% higher than 762MPa at room temperature. The excellent high temperature strength of composites is attributed to tungsten matrix transitting from brittle to ductile with increasing temperature, which makes the strengthening effect of ZrC particle be more significant at high temperature. The strengthening mechanism at high temperature is dislocation strengthening, load transfering and crack pinning.
Key words: tungsten matrix composites ZrC particle high temperature strength ductile-brittle transition
