(1. 南京航空航天大學(xué) 機(jī)電學(xué)院，南京 210016； 2. 揚(yáng)州大學(xué) 機(jī)械工程學(xué)院，揚(yáng)州 225127； 3. 南昌大學(xué) 機(jī)電工程學(xué)院，南昌 330031)
摘 要: 在氬氣氣氛條件下利用Cu-Sn-Ti預(yù)合金釬料實(shí)現(xiàn)人造金剛石磨料與KSC82鋼絲的釬焊連接，制作長(zhǎng)度500 m，基體直徑約為0.7 mm的金剛石線鋸。利用掃描電子顯微鏡及能譜儀觀察并分析金剛石釬焊界面特征及微區(qū)元素分布規(guī)律，探討釬料及釬焊界面元素氧化特性，開展線鋸彎曲疲勞實(shí)驗(yàn)。結(jié)果表明：Cu-Sn-Ti合金在釬焊后內(nèi)部形成成分發(fā)生偏析的組織，金剛石磨粒釬焊界面Ti元素明顯偏析，金剛石通過反應(yīng)型潤(rùn)濕方式實(shí)現(xiàn)釬焊連接。氬氣通入流量影響線鋸工作層合金表面顯色，當(dāng)氬氣流量Q≥15 L/min時(shí)，線鋸工作層表面呈金黃色；當(dāng)10 L/min≤Q≤15 L/min時(shí)，呈藍(lán)色；當(dāng)5 L/min≤Q≤10 L/min時(shí)，呈紫紅色，工作層合金表面Ti元素的氧化層厚度決定其表面可見顏色類型。線鋸工作層表面彎曲疲勞裂紋首先發(fā)生于無釬料合金包覆的基體表面，增大彎曲曲率，金剛石釬焊界面處裂紋發(fā)生并沿著垂直于釬焊界面方向向釬料合金擴(kuò)展，具有典型的張開型表面裂紋特征。
關(guān)鍵字: Cu-Sn-Ti合金；釬焊金剛石線鋸；界面特征；彎曲疲勞裂紋
（1. College of Mechanical and Electrical Engineering, Nanjing University of Aeronautics and Astronautics, Nanjing 210016, China; 2. College of Mechanical Engineering, Yangzhou University, Yangzhou 225009, China; 3. School of Mechatronics Engineering, Nanchang University, Nanchang 330031, China）
Abstract:Diamond grits were brazed on the surface of the KSC82 steel wire by using Cu-Sn-Ti pre-alloy powder, diamond wire saw was produced with steel wire of diameter 0.7 mm and length 500 m. Diamond brazing interface features and elements distribution pattern were analyzed by using the scanning electron microscopy and energy disperse spectroscopy. Elements oxidation properties of diamond brazed interface were discussed, and fatigue bending test was carried out. The results show that the segregation of the alloying elements happens inside the Cu-Sn-Ti alloy after brazing heating treatment, Ti element segregates on the diamond brazed interface and its content increases 18 times. The diamond grains are brazed because of the titanium carbide. Titanium oxide phenomenon is found on the surface of Cu-Sn-Ti alloy, and only being found on Cu-Sn-Ti surface. Titanium oxide thickness depends on the argon flow Q during argon controlled atmosphere-brazing, when Q≥15 L/min, alloy surface shows gold color; when 10 L/min≤Q≤15 L/min, blue shows on the alloy surface; when 5 L/min≤Q≤10 L/min, alloy shows amaranth color. Bending fatigue crack occurs on the surface of KSC82 steel wire firstly, and cracks occurs in diamond brazing interface and growth along the circumferential of the wire saw to Cu-Sn-Ti alloy with the characteristics of opening mode crack when bending curvature increases.
Key words: Cu-Sn-Ti alloy; brazed diamond wire saw; interface characteristics; fatigue bending crack
