Abstract: Transparent polycrystalline spinel fabricated by hot pressing high pure ultrafine spinel powder in vacuum,then hot isostatic pressing the sintered body was reported in this paper.The optical and mechanical properties was measured.It has excellent mechanical,thermal and optical properties,high abrasion and erosion resistance as well.It also can resist the radiation of UV and sunlight.It has the similar properties as the sapphire and is cheaper than the later.The large size spinel is availible now.

Key words: Transparent polycrystalline spinel fabricated by hot pressing high pure ultrafine spinel powder in vacuum,then hot isostatic pressing the sintered body was reported in this paper.The optical and mechanical properties was measured.It has excellent mechanical,thermal and optical properties,high abrasion and erosion resistance as well.It also can resist the radiation of UV and sunlight.It has the similar properties as the sapphire and is cheaper than the later.The large size spinel is availible now.