热等静压Cr-Si靶材的特性及微结构研究

Properties and microstructure of Cr-Si target material manufactured by Hot Isostatic Press

热等静压(Hot Isostatic Press,HIP)技术是在惰性气氛中,在各向均衡的气体高压力及高温共同作用下,去除材料内部的孔洞及缺陷,以改善机械性质、使粉末材料及表面蒸镀物具一致性、通过扩散键结(diffusion bonding)改善焊接完整性等。热等静压适用于多种材料及器件,特别是铝合金、工具钢、钛、超合金以及蒸汽涡轮零件、医学植入件、自动化铸件、靶材与粉末冶金制品等。考虑到近年来随着高密度、高传输速率光储存媒体及平面显示器的发展,靶材的研究与开发,巳成为光学薄膜制造的关键技术,该文作者以热等静压方法改善金属靶材,比较热等静压前后靶材性质差异和论证批量生产的可行性;并探讨热等静压处理对靶材性质的影响、比较其显微结构变化,以评估热等静压改善金属靶材材之可行性。研究结果显示,利用1 100℃,175 MPa,4 h热等静压的制备流程条件,对3种不同成分配比之Cr-Si热压靶材进行热等静压处理,均可有效改善孔隙率,其中以50Cr-50Si的热等静压效果最为显著,孔隙率可有效降低60%。此外,靶材在经过热等静压后,由于炉内气体的纯化效应而使得靶材的氮、氧浓度皆有所上升,尤其是Si以单独元素形态存在时更甚,从而造成靶材纯度受到影响。

Hot Isostatic Press （HIP） technology is a forming process combining simultaneous heating and pressing to consolidate powders in high temperature, high pressure as well as under argon （Ar） atmosphere, primarily used to eliminate voids and defects in materials. General functions of the HIP include： eliminate the casting void, improve mechanical property, maintain the consistency of the surface evaporation from powder material, improve the integrity of welding by diffusion bonding. HIP is mainly applied to a wide range of materials, in particular aluminum alloy, tool steel, titanium and super alloys, as well as steam turbine components manufacture, medical implants, automatic casting and powder metallurgy, target material manufacturing, etc. Considering that, in recent years, with the development of high density, high transmission speed storage media and the plane display, research of target materials has become the key technique, the present paper aims at improving the properties of metal target material made by HIP, comparing the properties of the samples before and after HIP, evaluating the feasibility of large-scale production, and exploring the properties and microstructure change to evaluate the effect of HIP on metal target material. The results show that the HIP can decrease the porosity effectively for three kinds of Cr-Si target materials with different ingredients percentages under the conditions of 1 100 ℃, 175 MPa and 4 h. The effect on 50Cr-50Si is the most remarkable one, and the porosity can be reduced by 60%. In particular, after HIP, the purity of target material may increase with the increasing of nitrogen/oxygen concentration as the result of the gas purification effect in stove, especially in case of Si exists as elementary substance/free element.