Experimental Procedure of ZrB2

Commercially available ZrB2 powder (Dandong Chemical Co. Ltd., Dandong, China, the average particle size was 2.5 μm, multilateral shape, and the specific area was 5.24 m2·g−1), α-SiC powder (FCP 15C, SIKA TECH., Lillesand, Norway, multilateral shape, with a purity of >99% and an average particle size of <0.5 μm), B4C powder (Mudanjiang Jingangzuan Boron Carbide Co. Ltd., Mudanjiang, China, multilateral shape, and the average particle size was <1 μm). Water-soluble carbon black (Shanghai Yingchang Chemical Co. Ltd., Shanghai, China, spherical shape, and the average particle size was <1 μm) was used as raw materials. PEI (30 wt % aqueous solution, TCI, P0381) was selected as a dispersant. ZrB2 powder was attrition milled (Model 01-HD, Union Process Precision Machinery Co. Ltd., Qingdao, China) at 300 rpm for two h in ethanol medium in a Teflon-coated tank using cobalt-bonded WC media and a cobalt-bonded WC spindle. The particle size was refined to 0.32 μm after milling. To remove surface oxide impurity, ZrB2 was washed with a hydrochloric acid solution (1:1 in weight ratio) and freeze dried (FD-1A-50, Beijing Boyikang Experimental Instrument Co. Ltd., Beijing, China). The aqueous slurries were prepared as follows: ZrB2, SiC, B4C, and C powders, together with PEI (all contents were based on the weight percentages of dry powders), were dispersed into water, and then stirred at 400 rpm for one h. Moreover, since an oxide layer on the powder surface inhibits its high-temperature densification progress, sintering aids such as B4C and carbon are usually required. On the other hand, previous researchers used polyethyleneimine (PEI) to disperse monolithic ZrB2 effectively. PEI was reported in several studies to be an appropriate dispersant for SiC and B4C powders. However, until now, the aqueous co-dispersion behavior of a ZrB2–SiC–B4C–C (ZSBC) powder system has rarely been reported, which is crucial to the subsequent consolidation process. In the present work, the properties of ZSBC suspension are investigated in terms of surface charge, adsorption, and rheological behavior to obtain a well-co-dispersed suspension. If you are looking for high quality, high purity and cost-effective Zirconium diboride, or if you require the latest price of Zirconium diboride, please feel free to email contact mis-asia.

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