Improvement of 20crni2mo gear carbonization process 材料齒輪滲碳工藝改進
Moreover , high quality nanocrystalline p - sic film was attained with the integration of the pre - carbonization process and the substrate bias effect 進一步結合襯底預碳化以及對襯底的偏壓作用,得到了高質量的納米? sic薄膜。
This thesis reports some results on the hot press sintering of nano - composite wc - co powder , which is prepared by spray pyrogenation & continuous deoxidization and carbonization process 本課題采用熱壓燒結技術對以噴霧熱解?連續(xù)還原碳化法制備的納米復合wc - co粉末進行了熱壓燒結研究。
This article discuss several effecting factors about pan - base carbon fiber strength . we make emphasis on annlysis the influencing factors of polymerization pro - oxygen carbonization process 摘要本文分析了碳纖維研發(fā)過程中對強度的影響因素。著重對原絲生產(chǎn)、預氧化過程、碳化過程中的主要影響因素分別進行了分析。
By increasing the h2 dilution ratio , it is found that atomic hydrogen can selectively etch amorphous phase and stabilize crystalline phase . from the study on the distance from substrate to catalyzer , choosing a proper distance can ensure the gas fully decomposed , while a relatively low substrate temperature can cause the nanocrystalline particles to lose mobility and keep their sizes . the pre - carbonization process can enhance the nucleation density and make the growth of high quality nanocrystalline p - sic films much easier 實驗結果表明:隨著工作氣壓的減小,薄膜的晶粒尺寸有所減小;通過提高氫氣稀釋度,利用原子氫在成膜過程中起的刻蝕作用,可以穩(wěn)定結晶相并去除雜相;選擇適當?shù)臒峤z距離能保證反應氣體充分分解,又使襯底具有較高的過冷度,是形成納米薄膜的重要條件;采用分步碳化法可以提高形核密度,有利于獲得高質量的納米- sic薄膜;襯底施加負偏壓可以明顯提高襯底表面的基團的活性,因負偏壓產(chǎn)生的離子轟擊還能造成高的表面缺陷密度,形成更多的形核位置。