【摘要】 本文研究了在4.0GPa 和1550℃下非晶玻璃转化成翡翠的晶化过程中,时间参数对翡翠的结晶度及硬度的影响.发现在该实验条件下晶化时间在15min 内得到的翡翠有两个硬度值.由结晶度曲线可知,要使非晶全部转化成翡翠,晶化时间至少要>15min.另外,还利用断面的 SEM 分析观察了翡翠的晶粒编织、生长情况,并就翡翠的成核及生长机理进行了初步探讨.翡翠的结晶及生长是一个很复杂的过程,本实验发现当翡翠的结晶生长完成时,其编织还在进行,增加高压下的保温时间,有利于翡翠形成紧密的编织,能更好地改善翡翠的宏观质地.此外,根据人工翡翠及天然翡翠的晶粒编织情况的对比,表明要达到天然翡翠的质地,需要减少成核数,增加晶体的生长速度,才能得到与天然翡翠同样的微观编织结构.更多还原

【Abstract】 The effect of the varying crystallizing times on hardness and crystallization degree ofsynthetic jadeites was studied in this paper.Jadeite was synthesized for jewelry by phasetransformation from glass of its stoichiometric composition NaAlSi₂O₆ under 4.0GPa and at1550℃.The hardness curve shows that two kinds of hardness appear on the same pieceof jadeite which was synthesized within 15min.The crystallization degree curve reveals thatglass was completely transformed into jadeite crystal when the crystallizing time is longer than15min.In addition,the penetrating fibrous texture of synthetic jadeite and its growth wereinvestigated by using SEM.Nucleation and growth of jadeite was also studied.The growth ofpenetrating fibrous texture was going on after glass was completely transformed into crystal.Itis necessary for synthesis of jadeite for a good quality jewelry to increase the crystallizing timeafter jadeite crystal was completely formed.In order to make the texture of synthetic jadeiteto be similar to that of natural jadeite,both less nuclei and higher growth rate are necessary.更多还原