Presents the investigation of the heat conduction behavior, internal thermal stress field of specimen under thermal shock and microscopic damage and failure of the tungsten based composites by combination of macroscopic and microscopic analyses and integration of material science and mechanics ; describes a microscopic mechanical model based on the microstructure of components with macroscopic stress applied to the microscopic model as that of maximum principal stress at the center, and the fringe of the specimen, and the microscopic stress fields obtained through calculation by the finite element method, and concludes from test results that the maximum principal stress is first generated inside the test coupon, and a failure will be first initiated in the inclusion if the material fails at this time ; the maximum principal stress moves to the edge of the test coupon after the test coupon is heated for a period of time, and the failure will first be initiated in the base if the material fails at this time
從材料設計的思想出發,採用宏觀與微觀、材料科學與力學相結合的方法,對
鎢基復合材料的熱傳導行為、材料在熱沖擊載荷下的內部熱應力場及材料細觀結構的破壞行為進行了詳細的理論研究.根據
鎢基復合材料的細觀組織結構建立了材料細觀模型.在宏觀分析的基礎上,分析了材料微結構內部的破壞行為.分別取試件心部與邊緣主應力值最大點的應力狀態,施加在所建立的模型上,用有限元方法計算了模型內部的彈性應力場.結果表明:試件主應力最大值首先產生在試件內部,此時,如果材料發生破壞將先從
夾雜中開始;加熱一段時間后試件中的最大主應力值轉移到試件邊緣,此時材料發生破壞將先從基體中開始
Abstract : comparision is made between the characteristics of recovered wcand conventional wc by clectronic probe detection. in view of perfect crystal lization, less defect in the crystal and sufficient compound carbon, cemented carbide superior to conventional wc is developed by process optimization to compensate for the high o2 content and more inclusions in the recovered wc
文摘:用電子探針檢測手段對比了回收碳化鎢和一般碳化鎢的不同特性,從回收碳化鎢具有結晶完整、晶內缺陷少、化合碳充足等優良性能出發,用工藝優化手段彌補回收碳化鎢氧含量高、夾雜物多等缺點,試制出了性能優于用一般碳化鎢生產的硬質合金。