【小星星(需筆記可加好友私訊】評論

磷酸結合包埋材的膨脹量、耐熱性、抗壓強度皆比石膏包埋材大！石膏包埋材：▶用α半水流酸鈣、▶耐熱能力低、▶脫臘時不能<370°也不能>700°C。▶若>700°C，耐火材矽土會與硫酸鈣起化學反應，生成SO2, SO3氣體。▶適用於金合金。磷酸結合包埋材：▶耐熱約1000°C，超過1375°C會鑄造失敗▶強度三者最大！▶適用鈷鉻合金矽酸乙酯結合包埋材：▶最耐高溫>1000°C▶無膨脹▶適用RPD frameworkＲ

【小甜瓜瓜】評論

②The binder holds the filler together and provides the investment strength. When the binder is heated at temperatures sufficiently high to completely dehydrate the investment, it shrinks considerably, and occasionally fractures. As Figure 14-5 shows, when the temperature is raised to 200 to 400 °C, it dehydrates and shrinks. A slight expansion occurs between 400 and 700 °C, and a large contraction then takes place at higher temperatures, caused by decomposition of the calcium sulfate. Thus it is imperative that gypsum investments not be heated above 700 °C.石膏結合包埋材的耐熱性不良，最好不要加熱超過700 °C。（較耐高溫的為磷酸鹽包埋材、矽酸乙酯鍵結包埋材）④Gypsum dies do not reproduce surface detail as well as electroformed or epoxy dies because the surface of the set gypsum is porous on a microscopic level石膏結合包埋材的透氣性較佳。