英语翻译wear can be defied as the progressive loss of material from the operating surface of a body occurring as a result of relative motion at the surface.the problem of wear arises wherever there are load and motion between surfaces,and is ther
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英语翻译wear can be defied as the progressive loss of material from the operating surface of a body occurring as a result of relative motion at the surface.the problem of wear arises wherever there are load and motion between surfaces,and is ther
英语翻译
wear can be defied as the progressive loss of material from the operating surface of a body occurring as a result of relative motion at the surface.the problem of wear arises wherever there are load and motion between surfaces,and is therefore important in engineering practice,often being they major factor governing the life and performance of machine components.the major types of weare are described next:
adhesive wear.when two surfaces aree loaded against each other,the whole of the contact load ise carried on very small area of the asperity contacts,the real contact pressure ate these asperities is very high,and adhesion takes place between them.if a tangential force is applied to the model shown in Fig.16.1,shearing can take place either (a) at the interface or (b) below or above the interface,causing adhesive wear.because of factors such as strain hardening at the asperity contact,the adhesive bonds often are stronger than the base metals,thus,during sliding,fracture usually occurs in the weaker or softer component,and a wear fragment is generated.although this fragment is attach to the harder component(upper surface in Fig.16.1c),it eventually becomes detached during further rubbing at the interface and develops into a loose wear particle.
also known as oxidation or chemical wear,this type of wear is caused by chemical or electrochemical reactions between the surfaces wear particles in this type of wear.when the corrosive layer is destroyed or removed through sliding,another layer begins to form,and the process of removal and corrosive layer formation is repeated
fatigue wear is caused when the surface of a material is subjected to cyclic loading,one example of this is the rolling contact in bearings.the wear particles usually are formed through spalling or pitting.another type of fatigue wear is by thermal fatigue.cracks on the furface are generated by thermal stresses from thermal cycling,such as when a cool forging die repeatedly contacts hot workpieces.these cracks then join,and the surface begins to spall,producing fatigue wear.
英语翻译wear can be defied as the progressive loss of material from the operating surface of a body occurring as a result of relative motion at the surface.the problem of wear arises wherever there are load and motion between surfaces,and is ther
defied?是不是defined.
磨损可定义为物体操作表面材料的累积损失,为表面相对运动结果所致.哪里的表面有载荷和运动,哪里便有磨损问题出现.因而磨损问题在工程实际中很重要,常是控制机器零件寿命和性能的主要因素.磨损的几种主要形式介绍如下:
粘附磨损.当两个表面相互接触承重时,整个的接触载荷作用在粗糙表面的一个很小的区域,故在这些粗糙表面的真正的接触压力很大,它们之间便发生粘附.如果把一个切向力施加在图16.1的模型上,剪切不是发生在分界面上(a),就是发生在其下面或上面(b),从而导致粘附磨损.由于各种因素,比如粗糙接触面硬化的压力,粘附连接常比本体金属更坚硬,因此,在这更弱或更软的部件上常会发生滑动或者断裂,产生磨损的部分.尽管这个部分连接在更硬的部件上(图16.1的上表面),但分界面的进一步摩擦最终将使它分离,变成一个松散的磨损零件.