کد مقاله کد نشریه سال انتشار مقاله انگلیسی نسخه تمام متن
1458972 989587 2016 11 صفحه PDF دانلود رایگان
عنوان انگلیسی مقاله ISI
Producing dense zirconium diboride components by room-temperature injection molding of aqueous ceramic suspensions
ترجمه فارسی عنوان
تولید اجزای سازنده دی بورید زیرکونیم متراکم با قالب گیری تزریقی سرامیکی آب در دمای اتاق
کلمات کلیدی
موضوعات مرتبط
مهندسی و علوم پایه مهندسی مواد سرامیک و کامپوزیت
چکیده انگلیسی

Aqueous suspensions of zirconium diboride (ZrB2), boron carbide (B4C) and tungsten carbide (WC) with dispersant and water-soluble polyvinylpyrrolidone (PVP) were investigated for processing by room-temperature injection molding, a novel, environmentally benign ceramic processing method. B4C and WC were used as sintering aids, and the as-received powders were attrition milled to reduce particle size to promote full densification of ZrB2 specimens by pressureless sintering. Zeta potential measurements of individual ZrB2, B4C and WC powders and of powder mixtures revealed that maximum stability was achieved in aqueous solutions of attrition milled powder mixtures dispersed using an ammonium polyacrylate dispersant. A maximum powder loading of 49 vol% with ≤5 vol% PVP was attained for ZrB2/B4C/WC suspensions with dispersant. Although exhibiting a time-dependent rheological response determined by parallel-plate rheometry, suspensions containing 49 vol% powders and ≤3 vol% PVP, as well as suspensions of 46 vol% powders and ≤4 vol% PVP, were flowable under the conditions of the process. ZrB2 rings prepared by room-temperature injection molding were machinable prior to binder removal and exhibited maximum brown densities of 56% true density (TD). Sintered densities were >98%TD with ~20% linear shrinkage. Scanning electron microscopy revealed an average grain size of 7.3±2.8 µm, and chemical analysis confirmed that no undesirable oxide phases remained in the sintered ZrB2 specimens. Aqueous ZrB2-based suspensions containing B4C and WC sintering aids and PVP were effectively processed via room-temperature injection molding to yield dense ZrB2 rings after binder burnout and pressureless sintering.

ناشر
Database: Elsevier - ScienceDirect (ساینس دایرکت)
Journal: Ceramics International - Volume 42, Issue 2, Part A, 1 February 2016, Pages 2750–2760
نویسندگان
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