气相缓蚀剂的研究现状与展望

从缓蚀剂的缓蚀基团和分子结构方面概述了气相缓蚀剂的研究现状，阐述了气相缓蚀剂的有关缓蚀机理。分析了缓蚀效果的影响因素．讨论了气相缓蚀剂的发展方向．     

Analysis of oxygen-18 tracer profiles in two-stage oxidation experiments (I): predominant oxygen diffusion in the growing scale

Typical two-stage oxidation experiments in high-temperature oxidation studies on metals are analyzed. Two cases of predominant oxygen diffusion in the scale are studied: pure volume diffusion and simultaneous transport via grain boundaries and via the bulk. An analytical expression for the growth of the oxide layer is given for the assumption that the chemical potential of the oxygen varies linearly over the oxide layer. The numerical treatment of the differential equation is improved so that the calculation is possibly faster and/ or more accurate compared to a method given in the literature. The experimental profiles are described by four parameters, the grain boundary width, the grain radius, and the volume and grain boundary diffusivities. Two equations correlating these parameters can be extracted from the profiles. Two benchmark tests are described for testing the program. An analytical solution is presented which approximately describes the distribution of O-18 in the oxide layer for pure volume diffusion. Experimental SIMS profiles on Fe-Cr-Al alloys are explored on the basis of our calculation.     

铝合金晶粒细化剂的发展趋势

综述近些年来铝合金晶粒细化剂的研究与应用状况。对Al-Ti、Al-Ti-B、Al-Ti-C、Al-Ti-C-B、Al-Ti-B-RE等晶粒细化剂进行了比较，并对具有代表性的细化理论如包晶反应、碳化物一硼化物及组织遗传性进行丁分析和讨论。认为添加了具有特殊性质稀土的Al-Ti-C-RE和Al-Ti-C-B-RE的多元合金晶粒细化剂是今后发展的方向。     

多弯弯曲件模具设计

介绍了多弯弯曲件冲模的凸模、凹模结构。剪式伸缩机构的运动特性使得凸模、凹模在竖直冲压的同时,其外侧部分可以横向移动,产生相应的送料动作。利用移动凸轮机构辅助成形,取件后凹模自动复位。     

金刚石框架锯锯切研究（2）一锯切破碎机理

在对金刚石框架锯锯切加工动力学研究的基础上，通过单颗粒划痕和单个金刚石结块切削大理石试验，模拟金刚石框架锯锯切过程中，金刚石颗粒和结块在不同加工条件下的切削过程；测量分析了切削力、表面沟槽轮廊和有效切削磨粒数；观察并分析了加工表面形貌；运用岩石脆性断裂力学理论，分析了单颗粒金刚石切削机理。通过金刚石框架锯发加工大理石的切屑粒度分布分析，指出了实际加工切削条件对锯切破碎机理的影响。研究结果证实了金刚石框架锯锯工加工动力学研究的一些基本结论，最后提出了金刚石框架锯锯切大理石破碎机理模型。     

Al-Li合金回归机制的计算机模拟

基于离散格点形式的微扩散方程(Langevin方程),对Al-Li合金在回归过程中δ-Al_3Li相溶解进行了原子层面计算机模拟,分析了析出相在回归过程中原子图像和序参数的演化,进而探讨了Al-Li合金的回归机制.首次探明Al-Li合金的回归过程有序相演化序列为化学计量比δ′相→非化学计量比有序相→无序基体,并论证了亚稳区合金的回归过程更趋向于失稳区合金时效过程的逆过程;失稳区合金的回归过程更趋向于亚稳区合金时效过程的逆过程.     

激光淬火铁基烧结材料的摩擦与磨损

研究了两种不同成分铁基烧结材料经宽带激光表面处理后的显微组织和摩擦学特性。结果表明，铁基烧结材料的耐磨性显著提高。两种材料相比，在较低载荷下，组织为孪晶马氏体／位错马氏体混合材料具有较好的摩擦学特性。而在较高载荷下，组织为马氏体／下贝氏体复相的材料具有较好的摩擦学特性。     

铸造A356铝合金的拉伸性能及其断口分析

研究了铸造A356-T6铝合金板不同位置处的拉伸性能。采用扫描电子显微镜和光学显微镜对拉伸断口及断口纵剖面的组织形貌进行了观察分析。试验结果表明，铸造A356-T6铝合金的拉伸屈服强度随离浇道口平面距离的增加而减小，断裂强度则是先减小然后再增大，而延伸率随高度变化不明显。铸造A356-T6铝合金的平均屈服强度、断裂强度、延伸率和断面收缩率分别为216．64MPa，224MPa，1．086％和0．194％。断口分析表明拉伸断口的表面分布着杂质、孔洞、铸造缩孔和氧化膜等缺陷，断口表面也存在开裂的由碳、氧、铁、镁、铝和硅元素形成的复合粒子。铸造A356-T6铝合金在拉伸过程中，裂纹萌生于共晶硅粒子与基体结合处，并沿枝晶胞之间的共晶区域进行扩展，当前进的裂纹遇到取向不一致的共晶硅粒子时，裂纹将截断共晶硅粒子。铸造A356-T6铝合金拉伸断裂方式为沿胞（即穿晶）断裂的准解理断。     

Experimental investigations of machining characteristics and removal mechanisms of advanced ceramics in high speed deep grinding

Machining characteristics and surface integrity of advanced ceramics, including alumina, alumina–titania, and yttria partially stabilized tetragonal zirconia, were studied under high speed deep grinding conditions. Material removal mechanisms involved in the grinding processes were explored. The material removal in the grinding of alumina and alumina–titania was dominated by grain dislodgement or lateral cracking along grain boundaries. The removal for zirconia was via both local micro fracture and ductile cutting. It was found that under a feed rate of 500 mm/min and for all the wheel speeds used, an increase in the wheel depth of cut (DOC) from 0.1–2 mm slightly improved the ground surface finish, but greatly prolonged the wheel life. This increase did not deepen the subsurface damage layer for the alumina and alumina–titania, but resulted in a slightly deeper damage layer for the zirconia.     

Ti_3Al基合金(0001)_(α_2)//(110)_β界面价电子结构分析

基于固体与分子经验电子理论,以改进的TFD理论提出的电子密度连续的量子力学条件为判据,计算了Ti3Al基合金中(0001)α//(110)β2界面的价电子结构。对比分析了单相Ti3Al基合金2-Ti3Al2-(Ti)Al(0001)//(0001)ααxMy界面与多相Ti3Al基合金(0001)α2-Ti3Al//(110)β-Ti0.5xAl0.5M0.5y,(0001)α2-(TixMy)Al//(110)β-Ti0.5xAl0.5M0.5y界面电子结构。从电子结构层次上初步解释了延性β相改善合金薄弱的相界面电子结构与键结合,增加界面稳定性与连续性,提高合金强韧性的微观本质。