Abstract : in this paper , a kind of technological scheme for one - step precision forging spur gear with large module is put forward by using positive friction role . experiment , in which commercial pure lead is taken as test material , is done in the special die designed , and force vs . stroke curve is recorded . it is shown that positive friction role can efficiently make a contribution to the filling of the tooth cavity , but increase forming force 文摘:针对大模数直齿圆柱齿轮，提出了利用积极摩擦一步成形的工艺方案，并用工业纯铅作为试验材料，在设计的专用模具上进行试验，记录了力? ?行程曲线，结果表明：利用积极摩擦作用能够有效地保证直齿圆柱齿轮精锻时齿腔充满，但同时增加了变形力。
Copper - nanosized tibi composites were prepared by in - situ process . the microstructure , mechanical and electrical properties , and dry sliding wear behavior and electric sliding wear of cu - nanosized tib _ 2 in - situ composites was investigated ; mostly task as follows : the thermodynamic data for the reactions between b and ti in the molten liquid of copper were analyzed , the copper matrix composites reinforced by in - situ tibi nanoparticles were prepared by reactions of 8263 , carbon and titanium in copper - titanium melt , and copper - titanium , copper - boron in alloy melt , respectively , which controlled the reaction temperature , reaction time and solidification process . the rnicrostructure and mechanical and electrical properties of the in - situ composites were investigated by using optics microscope , tem and xrd 本文采用原位反应法制备了cu -纳米tib _ 2原位复合材料，在此基础上分析了原位复合材料的微结构，进行了干滑动摩擦磨损和电接触滑动磨损实验，完成的主要工作如下：从热力学的角度出发，分析了陶瓷tib _ 2颗粒在铜基体中原位生成的热力学条件，并用电解铜、工业纯钛、 b _ 2o _ 3 、 c (还原剂)以及cu - ti 、 cu - b等合金为原料，通过控制适当的反应温度、反应时间和快速凝固等工艺手段，制备了cu -纳米tib2原位复合材料。
In the present dissertation , five commercial metallic materials ? tungsten alloy ( 93w ) , oxygen free copper ( ofc ) , titanium alloy ( tc - t ) , pure aluminum ( al ) and magnesium alloy ( mb2 ) were chosen as the composite system of the flier - plate with graded wave impedance , and their acoustic and mechanical parameters were measured . the thickness of each material was controlled so that flier - plates with a parabolic or cubic wave impedance distribution were designed 依据实现准等熵压缩和超高速发射对梯度飞片体系的理论要求，论文首先在一个较宽的波阻抗变化范围内，确定钨合金( 93w ) 、无氧铜( ofc ) 、钛合金( tc _ 4 ) 、工业纯铝( al )和镁合金( mb _ 2 )五种综合性能良好的金属和合金材料作为波阻抗梯度飞片的复合体系，并测量了材料的相关声学和力学参量。
Meanwhile , in the experimental work , the scope of the equation that reveals the relation between the magnet force and the working distance is defined definitely . different materials of the magnet core are compared in terms of their influence to the valve . however , it is only initiatory , more work needs to be done in the future 同时，还采用试验研究的手段深入分析了电磁阀工作间隙与电磁吸力之间的关系，明确了吸力公式的应用范围，同时，在不同材料的对比试验中，分析了磁性能较好的铁氧体和铁铬合金以及工业纯铁对电磁阀工作性能的影响，对合理确定电磁阀铁芯的制作材料进行了初步的探讨。
