饲料中钙镁的原子吸收测定法研究

研究了用火焰原子吸收法测定饲料中钙镁的方法，确定了方便快速地测定饲料中钙镁的条件，方法的回收率98%-107%,RSD低于6.9%，结果满意。     

一种Al—Si系高强度铸造铝合金的研制

阐述研制生产一种Ａｌ－Ｓｉ系高强度铸造铝合金，不用热处理强化σｂ即能达到３００Ｍｐａ，δ≥３％，用正交试验法先找出Ａｌ－Ｓｉ系多元合金的最佳化学成分，再用调整成分，变质处理等方法使该种合金的性能指标达到甚至超过日本ＡＤＣ１２合金。     

非自熔性铜粉与铸铁喷焊结合的界面研究

在非自熔性铜合金粉末中加入特制的添加剂,使粉末具有自熔性,并改善了喷焊的工艺性及感应加热熔敷结合的工艺性。此添加剂促进了铜液与铸铁表面的润湿性,在喷焊时生成一层薄膜覆盖在铜液之上,减少了铜液在高温下的氧化,在Cu与Fe的界面间发生扩散结合,从而提升了普通粉末的使用价值。经微观分析,发现结合界面牢固致密,机械性能完全满足零件的使用要求。     

Composition dependence of viscosity for Al_(1-x)Mg_x(0=x=0.10) alloys

Viscosities of molten Al(1-x)Mgx (0≤x≤0.10) alloys have been measured in the temperature range of 973 K―1173 K by a torsional oscillation cup method. The viscosity dependence on temperature for Al(1-x)Mgx (0≤x≤0.10) melts obeys Arrhenius equation. The viscosity increases with increasing mag-nesium concentration in the investigated system. There is an important relationship between viscosity and its glass-forming ability for metallic melt.     

轴承合金上化学镀镍技术的研究与应用

对轴承合金化学镀镍进行了研究,确定了合适的前处理工艺,并采用中性NaCl浸泡、硬度测试等方法分析了镀层性能.结果表明：施镀1h后镀层厚度约为20μm,镀层均匀、致密、无明显缺陷,X射线衍射分析表明镀层组织为单一的镍相,在5% NaCl溶液中浸泡24h无腐蚀孔出现,可以给轴承合金提供一定的保护.     

Creep behavior and dislocation mechanism of Ni3Al based single crystal alloy IC6SX at 760°C

The creep behavior and dislocation mechanism of Ni₃Al-based single crystal alloys IC6SX with crystal orientation [001] which was prepared by seed crystal method under the testing conditions of 760 ​°C/500 ​MPa,760 ​°C/540 ​MPa and 760 ​°C/580 ​MPa were investigated. The experimental results showed that the creep properties, dislocation morphology and mechanism of this alloy were different under different stress conditions. With the stress increasing from 500 ​MPa to 580 ​MPa, the creep life decreased from more than 1000h to 32.64h. The cubic degree of γ′ phase in single crystal alloy decreased obviously and the size of γ′ phase increased. The mechanism of dislocation movement also changed with the increasing stress. It was found that after the specimen was tested under the condition of 760 ​°C/500 ​MPa the dislocation network prevented the movement of dislocations and it was difficult for dislocations to enter the γ′ phase from the γ/γ′ interface. When the stress was 540 ​MPa, the dislocations cut into the γ′ phase by stacking fault. Furthermore, with the stress increasing to 580 ​MPa, the dislocation entered the γ′ phase in the form of extended dislocation and Lomer-Cottrell dislocation.     

Numerical modeling of annular electromagnetic stirring with intercooling in direct chill casting of 7005 aluminum alloy billet

Uniform direct chill(UDC) casting method was developed by combining annular electromagnetic stirring(AEMS) with intercooling in direct chill casting. In order to investigate effect of UDC on flow patterns, temperature profiles and solidification during the casting, a numerical model of the UDC casting process was developed and used to simulate the UDC casting process for preparing 7005 aluminum alloy billets. The comparison of the calculated results of UDC casting with normal direct chill(NDC) casting indicated that flow patterns, temperature profiles and the sump depth are modified remarkably by the application of annular electromagnetic stirring and intercooling during the direct chill casting. The sump profile and the temperature history during UDC casing were studied, and the mechanism of the casting process were discussed. The comparisons between the simulations and experimental results suggested that the proposed model provides good agreement for the sump profiles and the temperature history within the billets.     

双边约束下形状记忆合金梁的混沌运动

基于非光滑系统的Melnikov方法, 研究谐和激励下双边约束形状记忆合金梁的混沌运动, 得到了系统出现Smale马蹄混沌的必要条件, 并通过数值仿真研究系统的相图、 Poincaré截面图以及最大Lyapunov指数. 结果表明: 数值仿真结果与Melnikov准则下的解析结果相符； 当参数取特定值时, 较大的碰撞恢复系数可抑制混沌, 较大的谐和激励幅值可促进混沌产生.     

Low-frequency damping behavior of closed-cell Mg alloy foams reinforced with SiC particles

The damping properties of an Mg alloy foam and its composite foams were investigated using a dynamic mechanical thermal analyzer. The results show that the loss factors of both the Mg alloy and its composite foams are insensitive to temperature and loading frequency when the temperature is less than a critical temperature T_crit. However, it increases when the temperature exceeds the T_crit values, which are 200 and 250℃ for the Mg alloy foam and the Mg alloy/SiC_p composite foams, respectively. The Mg alloy/SiC_p composite foams exhibit a higher damping capacity than the Mg alloy foam when the temperature is below 200℃. By contrast, the Mg alloy foam exhibits a better damping capacity when the temperature exceeds 250℃. The variation in the damping capacity is attributed to differences in the internal friction sources, such as the characteristics of the matrix material, abundant interfaces, and interfacial slipping caused by SiC particles, as well as to macrodefects in the Mg alloy and its composite foams.     

硬质合金高压喷嘴毛坯压制模具耐磨性的研究

研究了硬质合金（YG14）和45钢渗硼层、硼铬共渗层的耐磨性。在此基础上，进行了模具寿命对比试验，确定了合理的模具选材和表面强化工艺。