常用靶材之熱機加工特性研究

Abstract

鎳有優異的高溫強度、耐腐蝕性，磁特性和全面的耐久性故在世上受到廣泛的應用。在今日，鎳的主要用途是作為提供強化與保護3000多種金屬，包含銅、不鏽鋼、白金等的媒介。 本論文將藉由Gleeble熱加工機對鎳靶材及其他多種常用靶材做不同條件的熱加工處理後，進行應力應變的分析及金相組織觀察，能找到最有效率的熱加工製程條件，進而提高濺鍍靶材的使用率。實驗項目包括：壓縮試驗、應力應變分析和加工性測試、金相組織觀察、X光繞射分析。同時並研究這些材料適合作為靶材的最佳製程條件(包含均勻度和晶粒大小)。 在鎳材的部分，實驗結果顯示：(1)鍛造的成形應力在各個溫度幾乎都呈現應力軟化或達到穩態的現象，且有動態再結晶的現象發生。尤以低溫高應變率時最為明顯，隨著應變率減低和溫度升高，動態再結晶現象的曲線趨於平滑不明顯。(2)應變率和溫度對<111>晶向強度的影響並無較一致性的規律。(3)在1050℃，各個晶向強度和不同應變率的關係圖(圖5-58)中，壓縮量對織構強度微微呈現線性的關係。(4)在應變率5s-1下以及在應變率0.5 s-1下1150℃和應變率0.05 s-1下1050℃時，<111>晶向所呈現的強度相對較弱。是在製造靶材時可以考慮的製程條件。 在其他材料的部分，實驗結果顯示：(1)AlCu經過450℃退火的均質化處理的晶粒大小，隨著退火時間的增加而更均勻一致，是適合作為靶材的優良製程條件。(2)AlSi經過450℃退火的均質化處理的晶粒大小，隨著退火時間的增加而更均勻一致，是適合作為靶材的優良製程條件。(3)NiCr(56-44)和NiCrSi(47.5-47.5-5)和NiCrSiAl(50-44-4-2)由於晶粒仍舊較大，且在邊界上有再結晶的晶粒發生，故尚無合適的製程條件。(4) Ti壓縮量越大是越適合的製程條件。

Nickel is a versatile material in the industrial world owing to its excellent strength at high temperature, strong resistance to corrosion, excellent magnetic and tensile properties. Today, Nickel is used to strengthen many metals that include copper, stainless steel, platinum, etc. The Gleeble machine was used to study the thermal mechanical properties of Nickel and other target materials. After hotworking, the stain-stress relation and metallographic observation were analyzed . The experiments include: Compression testing, OM, X-Ray diffraction analysis, metallurgical observation. The manufacturing process diagram was also developed and constructed for the Nickel target. The experimental results for the Ni target show that: (1) The forming stress, during forging at different thermal gradients, can reach a state of strain softening, stabilizing or even dynamic recrystallization (DRX). The softening strain is especially evident at higher temperatures. Therefore, with the reduction of the softening strain and the increase in temperature, the DRX graph is approach to a stable curve. (2) The effect of strain and temperature on the strength of the <111> orientation of the crystal does not follow any predefined rule. (3) At 1050℃, the relationship between the strength and the degree of compression is roughly linear. (4) At a strain of below 5s-1, 0.5 s-1 (1150℃) and 0.5 s-1 (1050℃), the strength in the <111> orientation are much weak and these are useful information in the production of Ni targets. The experimental results for the other target materials are as follows: (1)After annealing at 450℃, the grain size of AlCu and AlSi crystals become more uniform with the increase of annealing time. This is an useful information in the processing of these target materials. (2)The crystals of NiCr(56-44), NiCrSi(47.5-47.5-5) and NiCrSiAl(50-44-4-2) are still bigger and no boundary recrystallization occurred, therefore there is no suitable process condition for these target materials. (3) Heavy compression is suitable for manufacturing of Ti target