军用柴油发电机组在实现静音或超静音的同时要求良好的高温性能。通过研制机组50℃高温环境试验验证,掌握机组内部关键位置及重要区域温升情况。计算发动机、发电机等主要热源传热量,增加发动机气缸散热片,确保非额定工况下发动机传热...军用柴油发电机组在实现静音或超静音的同时要求良好的高温性能。通过研制机组50℃高温环境试验验证,掌握机组内部关键位置及重要区域温升情况。计算发动机、发电机等主要热源传热量,增加发动机气缸散热片,确保非额定工况下发动机传热量。设计离心风机加轴流风机辅助进风方案,对关键部位进行高效冷却,效率为自然进风5倍以上,实现1 m处声压级低于75 d B(A)且通过高温试验,为军用静音发电机组的研制提供参考。展开更多
An advanced rheomoulder,which is a device in the integration of melting metal,storage,slurry preparation,transportation and injection forming,was introduced and used to manufacture rheomoulding AZ91 D alloy.Effects of...An advanced rheomoulder,which is a device in the integration of melting metal,storage,slurry preparation,transportation and injection forming,was introduced and used to manufacture rheomoulding AZ91 D alloy.Effects of pouring temperature and cylinder temperature on microstructures and mechanical properties of rheomoulding AZ91 D alloy were investigated.The results show that the process can obtain such rheomoulding AZ91 D in which primary α-Mg particles are fine,spherical and uniformly distributed in the matrix.With the decrease of pouring temperature,the morphology of primary α-Mg particles changes from coarse rosette-like to fine spherical shape gradually.As the cylinder temperature decreases,the average size of primary α-Mg particles decreases firstly and then substantially maintains stable while the sphericity and solid fraction increase continuously.Also,decreasing pouring temperature or cylinder temperature properly contributes to improving mechanical properties of rheomoulding AZ91 D for the refinement of α-Mg particles and the decrease of porosity fraction.Furthermore,rheomoulding AZ91 D performs much better than thixomoulding,rheo-diecasting and high pressure die-casting（HPDC） in terms of mechanical properties.Compared with HPDC,the tensile strength,yield strength and elongation are increased by 27.8%,15.7% and 121%,respectively.展开更多
文摘军用柴油发电机组在实现静音或超静音的同时要求良好的高温性能。通过研制机组50℃高温环境试验验证,掌握机组内部关键位置及重要区域温升情况。计算发动机、发电机等主要热源传热量,增加发动机气缸散热片,确保非额定工况下发动机传热量。设计离心风机加轴流风机辅助进风方案,对关键部位进行高效冷却,效率为自然进风5倍以上,实现1 m处声压级低于75 d B(A)且通过高温试验,为军用静音发电机组的研制提供参考。
基金Project(2011CB606302-1)supported by the National Basic Research Program of ChinaProject(2013AA031001)supported by High-tech Research and Development Program of China
文摘An advanced rheomoulder,which is a device in the integration of melting metal,storage,slurry preparation,transportation and injection forming,was introduced and used to manufacture rheomoulding AZ91 D alloy.Effects of pouring temperature and cylinder temperature on microstructures and mechanical properties of rheomoulding AZ91 D alloy were investigated.The results show that the process can obtain such rheomoulding AZ91 D in which primary α-Mg particles are fine,spherical and uniformly distributed in the matrix.With the decrease of pouring temperature,the morphology of primary α-Mg particles changes from coarse rosette-like to fine spherical shape gradually.As the cylinder temperature decreases,the average size of primary α-Mg particles decreases firstly and then substantially maintains stable while the sphericity and solid fraction increase continuously.Also,decreasing pouring temperature or cylinder temperature properly contributes to improving mechanical properties of rheomoulding AZ91 D for the refinement of α-Mg particles and the decrease of porosity fraction.Furthermore,rheomoulding AZ91 D performs much better than thixomoulding,rheo-diecasting and high pressure die-casting（HPDC） in terms of mechanical properties.Compared with HPDC,the tensile strength,yield strength and elongation are increased by 27.8%,15.7% and 121%,respectively.
