利用淀粉原位凝固成型技术可制备具有形状精度高、致密、均匀的各种复杂形状的陶瓷坯体 ,高固相含量、低粘度料浆的制备是淀粉原位凝固成型工艺的关键技术。通过对 Si C粉进行表面包覆改性和选用合适的分散剂对炭黑粉进行有效分散的方...利用淀粉原位凝固成型技术可制备具有形状精度高、致密、均匀的各种复杂形状的陶瓷坯体 ,高固相含量、低粘度料浆的制备是淀粉原位凝固成型工艺的关键技术。通过对 Si C粉进行表面包覆改性和选用合适的分散剂对炭黑粉进行有效分散的方法 ,成功制备固相体积分数达 6 3%、表观粘度为 6 6 3m Pa· s的改性 Si C/炭黑稳定料浆。并研究了分散剂用量、料浆 p H值、体系固相体积分数对料浆流变性的影响。展开更多
通过硅烷偶联剂处理以及丙烯酰胺单体在其颗粒表面上的接枝聚合对 Si C微粉进行表面改性 ,获得了在酸碱条件下均可水基稳定分散的有机包覆改性 Si C粉体 ,制备出固相体积分数≥ 5 0 %、表观粘度在 1Pa· s以下、稳定性好的Si C料浆...通过硅烷偶联剂处理以及丙烯酰胺单体在其颗粒表面上的接枝聚合对 Si C微粉进行表面改性 ,获得了在酸碱条件下均可水基稳定分散的有机包覆改性 Si C粉体 ,制备出固相体积分数≥ 5 0 %、表观粘度在 1Pa· s以下、稳定性好的Si C料浆。以 FTIR光谱、离子电导率、Zeta电位的测试结果来表征改性前后粉体表面物质的化学组成和 Si C颗粒的胶体行为 ,以料浆粘度和流动特性来表征改性对 Si C粉体分散性的影响 ,从而进一步分析有机包覆改性 Si C粉体水基分散的稳定机制。结果表明 :聚丙烯酰胺高分子链产生的空间位阻和 Si C颗粒表面的静电效应是料浆稳定分散的重要原因。展开更多
In order to develop high-performance diamond wheels,the vitrified bond with different contents of Li2O addition and corresponding diamond composites were prepared.The experimental results show that the addition of a s...In order to develop high-performance diamond wheels,the vitrified bond with different contents of Li2O addition and corresponding diamond composites were prepared.The experimental results show that the addition of a small content of Li2O leads the formation of the mullite phase in vitrified bond.When the Li2O content is 3wt%,the mullite content in the vitrified bond reaches the maximum.Whereas,the vitrified bond turns into a pure glass phase when the Li2O content further increases to 5wt%.The softening temperature of vitrified bond,wetting angle between the vitrified bond and the diamond film decrease with the increasing of the Li2O content.The softening point of the vitrified bond with 5wt% Li2O is 537 ℃ and the contact angle is 32°,which are 44 ℃ and 44° lower than those of the sample without Li2O.The CTE (coefficient of thermal expansion),the flexural strength and hardness of the diamond composite sample first increase and then decrease with the increasing of the Li2O content.When the Li2O addition is 3wt%,the flexural strength and hardness of the composites reaches the maximum values of 93 MPa and 98 HRB,respectively,which are 43.1% and 12.6% higher than those of the sample without Li2O.展开更多
文摘通过硅烷偶联剂处理以及丙烯酰胺单体在其颗粒表面上的接枝聚合对 Si C微粉进行表面改性 ,获得了在酸碱条件下均可水基稳定分散的有机包覆改性 Si C粉体 ,制备出固相体积分数≥ 5 0 %、表观粘度在 1Pa· s以下、稳定性好的Si C料浆。以 FTIR光谱、离子电导率、Zeta电位的测试结果来表征改性前后粉体表面物质的化学组成和 Si C颗粒的胶体行为 ,以料浆粘度和流动特性来表征改性对 Si C粉体分散性的影响 ,从而进一步分析有机包覆改性 Si C粉体水基分散的稳定机制。结果表明 :聚丙烯酰胺高分子链产生的空间位阻和 Si C颗粒表面的静电效应是料浆稳定分散的重要原因。
基金Funded by the Zhejiang Provincial Key Research and Development Project(No.2018C01076)。
文摘In order to develop high-performance diamond wheels,the vitrified bond with different contents of Li2O addition and corresponding diamond composites were prepared.The experimental results show that the addition of a small content of Li2O leads the formation of the mullite phase in vitrified bond.When the Li2O content is 3wt%,the mullite content in the vitrified bond reaches the maximum.Whereas,the vitrified bond turns into a pure glass phase when the Li2O content further increases to 5wt%.The softening temperature of vitrified bond,wetting angle between the vitrified bond and the diamond film decrease with the increasing of the Li2O content.The softening point of the vitrified bond with 5wt% Li2O is 537 ℃ and the contact angle is 32°,which are 44 ℃ and 44° lower than those of the sample without Li2O.The CTE (coefficient of thermal expansion),the flexural strength and hardness of the diamond composite sample first increase and then decrease with the increasing of the Li2O content.When the Li2O addition is 3wt%,the flexural strength and hardness of the composites reaches the maximum values of 93 MPa and 98 HRB,respectively,which are 43.1% and 12.6% higher than those of the sample without Li2O.
