By x - ray analysis of the obtained samples the degree of the reaction was researched when the time of ball milling changed . at last the regularity of the metallurgical structure of tial alloy was investigated , when the high temperature changed . the following aspects were accomplished after hot hydrostatic extrusion 热静液挤压工艺:挤压后,坯料致密度有了较大的提高;分析了球磨时间跟挤压力的关系;对ti - al基合金室温断裂方式及断口形貌进行了一定的研究。
The fractorgraphy analysis show that in the layer rich in w and mo , the feature of fracture is brittle fracture which follow the bordline of crystal . in sections rich in the felt metal , the feature of fracture is ductile fracture . in w - mo layer , the feature of fracture are brittle fracture and some ductile fracture 断口形貌特征研究表明，富w区、富mo区主要为沿粒界脆性断裂；粘结金属发生韧性断裂； w - mo混合区为颗粒的沿粒界脆性断裂和粘结相的韧性断裂的混合型断裂；富ti区为典型的穿晶解理断裂； mo - ti混合区以穿晶解理断裂为主，颗粒边界表现出准解理断裂特征。
This paper concentrates on the mechanism of the strength and toughness of microalloyed steels 50crv by the heat treatment technique . we are looking for the ways to increase the mechanism of the strength and toughness by comparing the different effect of heat treatment at different index k of strength and toughness 通过采用适当的热处理工艺，对测得的不同热处理工艺的力学性能，组织结构和断口形貌的分析后认为，微合金化50crv钢通过适当的热处理工艺将可以同时提高材料的韧性和强度，获得良好的强韧性配合。
The relative density of the sample has reached as high as 97 . 4 % of fully dense . the mean micro hardness has reached hv496 . 3 . the fractography of the fracture section of the tensile sample was characteristic of dimple typically which indicated that the fracture belong to ductile fracture ；试样相对密度可以达到理论值的97 . 4 ；硬度方面由于激光立体成形工艺的特点，最后几层的硬度比开始时的高，平均硬度达到了hv496 . 3 ；拉伸试样的断口形貌具有典型的韧窝特征，属于延性断裂。
There is a slight drop of the fcpr when the specimen s thickness increases . however , the thickness of the specimen exerts a great influence on kth and fatigue life ( n ) : the thicker specimen is , the higher fatigue life ( n ) becomes , and the greater kth shows . under control of the same conditions , the fcpr of am50 is not so high as that of az91 . there are some correlations between load ratio ( r ) and the fatigue surface : when load ratio becomes great , small flat surfaces increase while dimples decrease 试样厚度增大，稳态裂纹扩展速率略有减小。但是，试样厚度影响试样的疲劳寿命和门槛值：试样越厚，疲劳寿命越长，门槛值越大；在试样尺寸和加载条件相同的情况下， am50的疲劳裂纹扩展速率较az91小，疲劳寿命则比az91长。载荷比r影响试样的断口形貌：载荷比r越大，对应相同k值出的断口小平面越多，韧窝越少。
In the present work , the chemical distributing , the microstructure characteristics and the fractorgraphy analysis of metal / metal fgm are studied systematically by using electron probe microstructure analysis ( epma ) , scanning electron microscopy ( sem ) and energy dispersive x - ray analysis ( eds ) . as a result , some ideas about the fabrication are put forward 然后分别应用电子探针( epma ) 、扫描电子显微镜( sem )和x射线能谱仪( eds )对共沉降法制备的w - mo系和w - mo - ti系梯度功能材料的化学成分分布、显微组织和断口形貌特征等进行了较详细的研究。
So cr30mo has good corrosion - abrasion resistance in phosphoric acid slurry . based on the analyses of microstructure , mechanical properties , corrosion - abrasion resistances and fracture of cast ferritic stainless steel cr30mo with various carbon content , it can be affirmed that high carbon is advantage to increase steel hardness , but disadvantage to suppress brittleness and increase corrosion - abrasion resistance 对不同含碳量的铁素体不锈钢cr30mo的组织结构、力学性能、磨蚀性能和断口形貌的分析后认为，碳含量增大，对钢的硬度提高有利，但对钢的韧性、耐磨蚀性很不利。
Cross section morphology analysis showed that the fracture appearance of tungsten carbide particle reinforced steel matrix composites was a mixture of quasi - cleavage fracture and toughness fracture . the fracture appearance of tungsten carbide particle always displayed as quasi - cleavage fracture , while the cross section morphology of steel matrix transformed with the heat treatment techniques 断口形貌分析显示， wc钢复合材料的断口形貌呈韧-脆复合断口特征，硬脆的wc颗粒常发生脆性解理断裂，而韧性较高的钢基体的断口形貌则因热处理工艺而异。
Abstract : by means of metallographical examination and sem , the microstructure characteristics , macro - and microfractographs of the brittle broken wheel hull bolt of bj212 automobile have been studied . the results show that the thin - headed screw , with excessively deep carbonitriding layer and hardening layer , has less resistance to brittle fracture in the thin area of its head . at the root of the head connecting the stem , a tensile stress may emerge owing to the non - even quenching stress . those are the two reasons for low torque fracture of bolt 文摘:借助金相、扫描电镜等手段对低扭矩脆断的bj212汽车轮壳螺栓的金相组织特征，宏观和微观断口形貌等进行了研究，结果表明：这种头部薄的螺栓，渗层和淬透层过深，使头部薄区脆断抗力降低，在头部与杆的根部，由于淬火应力不均匀导致根部产生拉应力，均是导致螺栓低扭矩断裂的原因。
The mechanical parameters at high temperatures - reduction in area ( ra % ) and tensile strength ( o b ) are measured by means of gleeble - 2000 thermal simulating machine . fracture surfaces are analyzed by scanning electron microscopy and optical microscopy . the segregation of sn is also examined by auger electron spectroscopy 通过测定试验钢种的高温力学参数(断面收缩率ra和抗拉强度_ b ) ，观察金相显微组织，分析扫描断口形貌，测试第二相析出物和俄歇能谱试验等方法，研究了残留元素sn及冷却速率对高温力学性能的影响。
