pressing adj. 1.(工作、要求等)急迫的,緊急的,迫切的。 2.(邀請等)懇切的。 a pressing business 急事。 a pressing danger 緊迫的危機(jī),燃眉之急。 n. 1. 壓;按。 2.壓榨;催逼。 3.沖壓;沖壓件;模壓制品。 4.唱片;同一批壓制的唱片。 He required no pressing. 他不需要催迫。 adv. -ly ,-ness n.
The main conclusions are drawn as follows : ( 1 ) for spray - forming ring of little thickness , densification results including friction mechanical property were investigated . after single - direction cyclic pressing , in the region near processing face , cavities close well and mechanical performances are better than those of region far from processing face 本論文的主要研究內(nèi)容和研究結(jié)論如下: ( 1 )對單、雙向楔壓工藝加工厚度較小的噴射沉積al - 20 % si / sicp復(fù)合材料環(huán)件的致密化效果以及致密化加工后環(huán)件的摩擦性能進(jìn)行了研究。
( 2 ) for the cyclic pressing technics , the thickness of densified layer of ring was studied , and the rules which the technics must follow had been investigated , and the influence of parameter on densification results had also been investigated . according to the theory of rolling , the conclusion of thickness of densification layer had been drawn for the dual - direction cyclic pressing . the term that decreased height of one stage and distance of one step advancing had been researched ( 2 )對楔壓壓透深度規(guī)律進(jìn)行了初步探索,同時對楔壓過程參數(shù)(單道次壓下量和楔壓步進(jìn)量)所要遵循的規(guī)律以及楔壓工藝參數(shù)(壓制方式、壓下量和壓制溫度)對坯件性能的影響進(jìn)行了研究。
Cyclic pressing is a new kind of densification processing , which is introduced to densify as - deposited ring of al - 20 % si / sicp . this paper includes the densification result and rule of this technics . the research shows that this technics can be successfully used to densify spray - forming porous material and can be availably adopted to improve mechanical performance and microstructure . this technics is characterized by simple equipment 、 small expense and flexible process , and these characters will make it come true to producing spray - deposited rings less costly 本文采用一種新型致密化工藝?楔壓工藝?對噴射沉積al - 20 % si / sicp大環(huán)進(jìn)行了致密化加工,采用密度硬度分布、抗拉強(qiáng)度變化和檢測顯微組織變化的實驗研究方法對其致密化效果及該工藝規(guī)律進(jìn)行了研究,通過研究表明了楔壓工藝可以成功地用來致密化噴射沉積多孔材料,該工藝有效地提高了噴射沉積大環(huán)件的致密度和抗拉強(qiáng)度并改善了組織。
Compared with those of as - sprayed ring , hardness and tension strength of area near processing face are increased by 45 % and 40 % respectively . friction mechanical performance of the ring is improved at large extent , and especially the wearing amount is merely 13 % of as - sprayed rings . after dual - direction cyclic pressing , the pore - closed state and the distributing of density and hardness are nearly identical in every part of ring . the friction mechanical property is close to that of single - direction - cyclic - press ring 靠近壓力加工面部位,硬度較沉積坯提高了45 % ,拉伸強(qiáng)度較沉積坯提高了40 % 。雙向楔壓后孔洞閉合、密度硬度分布都比較均勻。單向楔壓后,用壓力加工面作為摩擦面, al - 20 % si / sicp復(fù)合材料的摩擦磨損性能得到大幅度提高,尤其磨損量為楔壓前的13 % 。