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黄瓜嫁接栽培研究进展 被引量:35
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作者 王艳飞 庞金安 +1 位作者 马德华 李怀智 《北方园艺》 CAS 北大核心 2002年第1期35-37,共3页
嫁接能明显提高黄瓜对病虫害和不良环境的抗性 ,对水肥的吸收能力明显增强 ,并能够大幅度提高黄瓜产量和品质 ,尤其是早期产量。对黄瓜嫁接成活的机理、嫁接方法及嫁接后的管理进行了综述 ,认为应该加强对嫁接成活的机制、砧木的选育、... 嫁接能明显提高黄瓜对病虫害和不良环境的抗性 ,对水肥的吸收能力明显增强 ,并能够大幅度提高黄瓜产量和品质 ,尤其是早期产量。对黄瓜嫁接成活的机理、嫁接方法及嫁接后的管理进行了综述 ,认为应该加强对嫁接成活的机制、砧木的选育、嫁接机械的研制和嫁接育苗系统化的研究 。 展开更多
关键词 栽培 黄瓜 方法 接后处理
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大樱桃嫁接技术 被引量:1
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作者 闫瑞凤 宁玉霞 韩红 《河南科技》 2001年第8期19-19,共1页
关键词 大樱桃 接后处理
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Microstructure and mechanical properties of friction welds between TiA l alloy and 40Cr steel rods 被引量:4
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作者 董红刚 于连震 +3 位作者 高洪明 邓德伟 周文龙 董闯 《Transactions of Nonferrous Metals Society of China》 SCIE EI CAS CSCD 2014年第10期3126-3133,共8页
Direct friction welding of Ti Al alloy to 40 Cr steel rods was conducted, and the microstructure and mechanical properties of the resultant joints in as-welded and post-weld heat treatment(PWHT) states were investig... Direct friction welding of Ti Al alloy to 40 Cr steel rods was conducted, and the microstructure and mechanical properties of the resultant joints in as-welded and post-weld heat treatment(PWHT) states were investigated. The martensitic transformation occurred and brittle Ti C phase formed near the interface due to C agglomeration, which degraded the joint strength and increased the microhardness at the interface in as-welded state. Feathery and Widmanstatten structure generated near the interface on Ti Al alloy side. After PWHT at 580 °C and 630 °C for 2 h, the sorbite formed and C dispersed at the interface, leading to the increase of the joint strength from 86 MPa in as-welded state to 395 MPa and 330 MPa, respectively. The heat-treated specimen fractured with quasi-cleavage features through the zone 1 mm away from the interface on TiA l alloy side, but the as-welded specimen failed through the interface. 展开更多
关键词 TiAl alloy STEEL dissimilar metal joining friction welding post-weld heat treatment
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Effect of post-weld heat treatment on joint properties of dissimilar friction stir welded 2024-T4 and 7075-T6 aluminum alloys 被引量:4
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作者 B.SAFARBALI M.SHAMANIAN A.ESLAMI 《Transactions of Nonferrous Metals Society of China》 SCIE EI CAS CSCD 2018年第7期1287-1297,共11页
The effect of post-weld heat treatment on dissimilar friction stir welded AA7075 and AA2024 joints was studied. After welding in constant parameters, solution heat treatment and various aging treatments were given to ... The effect of post-weld heat treatment on dissimilar friction stir welded AA7075 and AA2024 joints was studied. After welding in constant parameters, solution heat treatment and various aging treatments were given to the welded joints. Microstructural and phase characterizations were done using optical microscope, SEM, FE-SEM, XRD and EDS techniques. Finally, mechanical properties of post-weld heat treated joints were evaluated and compared with as-welded joints. Results show that both 2024-T6 and 7075-T6 post-weld heat treatment procedures considerably improve the mechanical strength of the welded joint, with higher strength obtained for the 7075-T6 procedure, in comparison with the as-welded joint. This is explained by the formation of fine precipitates during the aging process, despite the abnormal grain growth. Fracture occurs at the interface between thermo-mechanical affected zone(TMAZ) and heat affected zone(HAZ) on the retreating side(AA7075) of as-welded joint, while by applying post-weld heat treatment fracture location shifts towards the stir zone(SZ) of the welded joint. Also, for post-weld heat treated samples, fracture surface is predominantly inter-granular, while in as-weld joint, fracture surface is mostly trans-granular. This is explained by dissolution and coarsening of precipitates within grains in post-weld heat treated joints. 展开更多
关键词 friction stir welding dissimilar welds post-weld heat treatment microstructure mechanical properties
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Effect of bonding temperature and heat treatment on microstructure and mechanical property of Mg−6Gd−3Y alloy vacuum diffusion bonded joints 被引量:2
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作者 Ping-yi MA Xu CHEN +2 位作者 Xing HAN Zhi-qiang LUO He-li PENG 《Transactions of Nonferrous Metals Society of China》 SCIE EI CAS CSCD 2022年第7期2205-2215,共11页
Diffusion bonding of as-cast Mg−6Gd−3Y magnesium alloy was carried out at temperatures of 400−480℃ with bonding pressure of 6 MPa for 90 min.Diffusion bonded joints were solution treated at 495℃ for 14 h and then ag... Diffusion bonding of as-cast Mg−6Gd−3Y magnesium alloy was carried out at temperatures of 400−480℃ with bonding pressure of 6 MPa for 90 min.Diffusion bonded joints were solution treated at 495℃ for 14 h and then aged at 200℃ for 30 h.Microstructures and mechanical properties of joints were analyzed.The results showed that rare earth elements and their compounds gathering at bonding interface hindered the grain boundary migration crossing bonding interface.Tensile strength of as-bonded and as-solution treated joints increased firstly and then decreased with the bonding temperature increasing due to the combined effects of grain coarsening and solid-solution strengthening.As-bonded and solution-treated joints fractured at matrix except the joint bonded at 400℃,while aged joints fractured at bonding interface.The highest ultimate tensile strength of 279 MPa with elongation of 2.8%was found in joint bonded at 440℃ with solution treatment followed by aging treatment. 展开更多
关键词 Mg−Gd−Y alloy vacuum diffusion bonding post-weld heat treatment bonding interface bonding strength
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果树苗木的休眠期嫁接
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作者 沈慧 《北京农业》 2003年第12期20-20,共1页
关键词 果树 苗木繁育 休眠期 砧木 接后处理
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Embrittlement and toughening in CGHAZ of ASTM4130 steel 被引量:4
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作者 LI LiYing WANG Yong +1 位作者 HAN Tao LI ChaoWen 《Science China(Physics,Mechanics & Astronomy)》 SCIE EI CAS 2011年第8期1447-1454,共8页
In the present investigation, a thermal welding simulation technique was used to investigate the mechanical properties and microstructure features of the coarse-grained heat-affected zone (CGHAZ) of ASTM4130 steel. Th... In the present investigation, a thermal welding simulation technique was used to investigate the mechanical properties and microstructure features of the coarse-grained heat-affected zone (CGHAZ) of ASTM4130 steel. The effect of post welding heat treatment (PWHT) and welding heat inputs on the toughness of CGHAZ was also analyzed. The results show that CGHAZ has the lowest toughness, which is only 5.5%-7.1% of the base metal. CGHAZ is mainly composed of dislocation martensite, up-per and lower bainite, and M-A constituents. But after PWHT, carbides precipitate from non-equilibrium microstructures of CGHAZ accompanying some retained austenite which transforms into low bainite, thereby enhancing toughness over the base metal. Therefore, the key microstructure factors affecting fracture toughness are lathlike non-equilibrium microstructure and lowered supersaturation before and after PWHT respectively. When welding heat input is between 12 kJ/cm and 28 kJ/cm, the mechanical properties in CGHAZ of ASTM4130 with single-pass welding can satisfy the requirements when PWHT is applied. 展开更多
关键词 ASTM4130 steel coarse-grained heat-affected zone EMBRITTLEMENT TOUGHENING
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