卧式加工中心试验模态分析

应用变时基采样的锤击法对卧式加工中心进行了试验模态分析，研究了该加工中心的动态特性，获得了感兴趣低频段的加工中心低阶固有频率。通过对整机各阶模态振型的分析，找到了加工中心结构的薄弱环节，为进行结构的优化设计指出了改进的方向。     

Simulation of local effect of reinforcement on temperature field during solidification of aluminum metal matrix composite

The effect of reinforcement on the solidification of pure metal matrix composites （MMCs） was simulated using a two-dimensional solidification temperature field model by the finite element method. The concept of the character length was proposed to describe the size of reinforcement local heat influential zone in MMCs solidification according to the change of the morphologies of solid-liquid interface. The relationship between the character length and the geometrical conditions, the boundary condition and physical properties of the reinforcement were studied, respectively. The results show that the width of the unit and the cold boundary temperature have no effect on the character lengths but have effect on the distance between cold boundary and reinforcement （/） and the thermal parameters of the reinforcement. An experimental rule to predict the value of the character length was derived and applied.     

EFFECT OF γ-IRRADIATION ON CuZnAl SHAPE MEMORY ALLOY

用透射电子显微镜和正电子湮没等分析手段,研究了CuZnAl形状记忆合金的γ辐照效应,此合金经一定剂量的γ辐照后,马氏体转变温度明显提高,而形状记忆功能仍保持不变。     

Formation and thermal stability of amorphous Ni-Mo-P alloys

The experimental researches on the chemical deposition of Ni-Mo-P amorphous alloys were carried out by adding Na2 MoO4 into acidic solutions. The optimum technology conditions were obtained by orthogonal design experiments. The structures and the relationship between compositions and their thermal stability were studied by energy spectrum (EC), scanning electron micrograph and X-ray diffraction spectrum. Compared with Ni-P amorphous alloys, the Ni-Mo-P amorphous alloys have high crystallization temperature and thermal stability, and the hardness reaches its peak when the annealing temperature is 500 ℃. With the increase of the heat treatment temperature, the surface morphology of the alloys changes.     

Electroless deposition of Ni on template of halloysite and its magnetic property

Halloysite template, a ceramic substrate, is of a hollow cylindric structure, on which the fine Pd nanoparticles are uniformly formed by the reduction of palldate chloride to initiate electroless deposition. The electroless deposition of Ni is catalyzed by the Pd particles, which results in a uniform layer of Ni-P alloy on halloysite. The alloy is of a nanocrystalline structure, of which the average diameter is about 6 nm. After being heat-treated at 400 ℃, it contains both Ni and Ni12P5 crystal, meanwhile, the Ni crystal gets larger with an average size of 51.9 nm.The content of phosphorous in the Ni layer has a great influence on crystal structure. The metallized halloysite has a higher inherent coercive force, and a much lower saturation magnetization in its as-plated state, while after heattreatment, the inherent coercive force decreases drastically. These magnetic properties have great relationship with the superparamagnetism of Ni nanocrystalline and the stress anisotropy in Ni layer.     

Abnormal Austenite-Ferrite Transformation Behaviors of Fe-ISi: Dilatometric Measurements

WITH THE APPEASING of competition of the totaloutput of iron and steels, the new generation of ultrahigh strength steel, based on the lessen the burden ofenvironment, double improvement of mechanicalproperties and elongation of the serving life, has beenfully outspreaded in the world. More and more researchwork shows that the solid-state microstructureevolution becomes the most effective route in thedevelopment of ultra-high strength steels. A process ofgreat interest in the steel produc…     

堆焊用药芯焊丝生产过程中的质量控制

针对堆焊用药芯焊丝生产过程中的质量控制问题，从设备状态、合金粉末、包粉量、焊丝刚度、减径量、拔丝粉、拉拔力和拉拔速度等方面提出了相应的措施，以保证和提高药芯焊丝质量的稳定性。     

ZTC4筒形件温成形扩口数值模拟

对铸造Ti-6Al-4V筒形件温成形扩口成形工艺进行了数值模拟分析,得出了优化的工艺参数,并对凸模锥角进行了优化模拟,得出了合适的锥角。     

液态铝合金表面张力快速检测新方法与装置

表面张力是液态合金的重要物性参数之一,铝合金表面张力与其变质处理效果及充型能力等质量参数密切相关,研究铸造铝合金表面张力快速检测方法及装置,对于开发铝合金熔炼质量炉前实时评价系统具有非常重要的实际意义.介绍了一种液态铝合金表面张力快速测试的新方法和新装置,新方法以固定时间内吹入被测液体的气泡个数以及气泡在生长过程中内部压差变化为信息参数,通过回归公式求解表面张力.基于该方法研制的表面张力新型测试装置由单片机测控单元、探头及其锁紧和升降机构、供气单元等部分构成.采用新装置可在5 s内测得铝合金表面张力,且具有较高的测试精度.