This paper presents the effects of different process parameters in producing Al-STi-1B grain refiner,i.e.various sequences and reaction time,on grain refinement efficiency of aluminum castings.It was found that differ...This paper presents the effects of different process parameters in producing Al-STi-1B grain refiner,i.e.various sequences and reaction time,on grain refinement efficiency of aluminum castings.It was found that different process parameters resulted in different morphology and size distribution of TiAl-3 and TiB-2 in grain refiner. The experiment was carried out by adding KBF-4 and K-2TiF-6 to molten aluminum.The melting temperature was controlled at 800℃in an electric resistance furnace.Three different sequences of KBF-4 and K-2TiF-6 additions were applied,i.e.,adding KBF-4 before K-2TiF-6,adding K-2TiF-4 before KBF-4 and mixing both KBF-4 and K-2TiF-6 before adding to molten aluminum.Three different holding time at 1 min,30 min and 60 min were applied.The results showed that no significant difference of morphology and size distribution was found by varying three different sequences.Whereas,the different holding time provided major differences in both morphology and size distribution,which are technically expectable from diffusion and agglomeration between particles resulting in larger particle size and wider range of size distribution of TiAI3 and TiB2.If the reaction time was longer than 30 rain,morphology of both TiAl-3 and TiB-2 became too large.If the reaction time was too short,less reaction between TiAl-3 and TiB2 to form would be obtained.For grain refinement efficiency, it was found that mixing KBF-4 and K-2TiF-6 before adding to molten aluminum with a holding time of 30 min resulted in best grain refinement efficiency.展开更多
【目的】龙骨骨折(keel bone fracture,KBF)已成为影响蛋鸡健康和生产的重要福利问题。试验旨在评估产蛋期龙骨骨折的发生与否对产蛋后期的蛋鸡恐惧行为、生产性能和蛋品质的影响。【方法】选取60周龄的海兰褐蛋鸡和林甸鸡各100只,单笼...【目的】龙骨骨折(keel bone fracture,KBF)已成为影响蛋鸡健康和生产的重要福利问题。试验旨在评估产蛋期龙骨骨折的发生与否对产蛋后期的蛋鸡恐惧行为、生产性能和蛋品质的影响。【方法】选取60周龄的海兰褐蛋鸡和林甸鸡各100只,单笼饲养于传统叠层式鸡笼。利用触诊和便携式X光仪区分龙骨骨折蛋鸡和未骨折蛋鸡,通过紧张不动性测试(TI)、旷场试验(OFT)和惊吓反射试验(SRT)依次测量恐惧行为反应,并测定68周龄时蛋鸡的生产性能和蛋品质。【结果】在TI试验中,2个品种龙骨骨折蛋鸡的紧张不动时长显著高于正常蛋鸡(P<0.05)。在OFT试验中,龙骨骨折的海兰褐蛋鸡和林甸鸡在穿过的格子数、步数和在外圈停留的时间均显著低于正常蛋鸡(P<0.05),在内圈停留的时间显著高于正常蛋鸡(P<0.05),且骨折的海兰褐蛋鸡的运动潜伏期显著高于正常蛋鸡(P<0.05)。在SRT试验中,龙骨骨折蛋鸡惊吓反射总得分显著低于正常蛋鸡(P<0.05)。因此,龙骨骨折蛋鸡的恐惧行为反应较强烈。2个品种龙骨骨折蛋鸡的产蛋率显著低于正常蛋鸡(P<0.05),且骨折的海兰褐蛋鸡蛋形指数低于正常蛋鸡(P<0.05),其余蛋品质参数在骨折蛋鸡和正常蛋鸡中无显著性差异(P>0.05)。【结论】龙骨骨折加剧了蛋鸡的恐惧行为反应,降低了产蛋后期蛋鸡的福利水平和生产性能。展开更多
文摘This paper presents the effects of different process parameters in producing Al-STi-1B grain refiner,i.e.various sequences and reaction time,on grain refinement efficiency of aluminum castings.It was found that different process parameters resulted in different morphology and size distribution of TiAl-3 and TiB-2 in grain refiner. The experiment was carried out by adding KBF-4 and K-2TiF-6 to molten aluminum.The melting temperature was controlled at 800℃in an electric resistance furnace.Three different sequences of KBF-4 and K-2TiF-6 additions were applied,i.e.,adding KBF-4 before K-2TiF-6,adding K-2TiF-4 before KBF-4 and mixing both KBF-4 and K-2TiF-6 before adding to molten aluminum.Three different holding time at 1 min,30 min and 60 min were applied.The results showed that no significant difference of morphology and size distribution was found by varying three different sequences.Whereas,the different holding time provided major differences in both morphology and size distribution,which are technically expectable from diffusion and agglomeration between particles resulting in larger particle size and wider range of size distribution of TiAI3 and TiB2.If the reaction time was longer than 30 rain,morphology of both TiAl-3 and TiB-2 became too large.If the reaction time was too short,less reaction between TiAl-3 and TiB2 to form would be obtained.For grain refinement efficiency, it was found that mixing KBF-4 and K-2TiF-6 before adding to molten aluminum with a holding time of 30 min resulted in best grain refinement efficiency.
文摘【目的】龙骨骨折(keel bone fracture,KBF)已成为影响蛋鸡健康和生产的重要福利问题。试验旨在评估产蛋期龙骨骨折的发生与否对产蛋后期的蛋鸡恐惧行为、生产性能和蛋品质的影响。【方法】选取60周龄的海兰褐蛋鸡和林甸鸡各100只,单笼饲养于传统叠层式鸡笼。利用触诊和便携式X光仪区分龙骨骨折蛋鸡和未骨折蛋鸡,通过紧张不动性测试(TI)、旷场试验(OFT)和惊吓反射试验(SRT)依次测量恐惧行为反应,并测定68周龄时蛋鸡的生产性能和蛋品质。【结果】在TI试验中,2个品种龙骨骨折蛋鸡的紧张不动时长显著高于正常蛋鸡(P<0.05)。在OFT试验中,龙骨骨折的海兰褐蛋鸡和林甸鸡在穿过的格子数、步数和在外圈停留的时间均显著低于正常蛋鸡(P<0.05),在内圈停留的时间显著高于正常蛋鸡(P<0.05),且骨折的海兰褐蛋鸡的运动潜伏期显著高于正常蛋鸡(P<0.05)。在SRT试验中,龙骨骨折蛋鸡惊吓反射总得分显著低于正常蛋鸡(P<0.05)。因此,龙骨骨折蛋鸡的恐惧行为反应较强烈。2个品种龙骨骨折蛋鸡的产蛋率显著低于正常蛋鸡(P<0.05),且骨折的海兰褐蛋鸡蛋形指数低于正常蛋鸡(P<0.05),其余蛋品质参数在骨折蛋鸡和正常蛋鸡中无显著性差异(P>0.05)。【结论】龙骨骨折加剧了蛋鸡的恐惧行为反应,降低了产蛋后期蛋鸡的福利水平和生产性能。
