マグネシウム タンケッショウ ノ ヒロウ ハカイ キョドウ

九州地区総合技術研究会in熊本大学, 第21回情報処理センター等担当者技術研究会(2009年9月3.4日開催)　ポスター発表

ディスプレイ用ガラスにおける圧子押し込み誘起表面残留応力の評価

Residual stress field around a Vickers diamond indentation was studied in three commercial glasses with different strain points (Ts=635°C, 570°C and 511°C, respectively). The basis of the experimental technique is to use cracks from a small indentation as a microprobe to measure the residual stress at a specific point around a large indentation and to study the change of the residual stress by heat treatment. Residual tensile and compressive stresses around a large indentation produced by applying the load of 19.6N were distributed up to a distance of about 400μm from the indentation center. For all specimens, the tensile and compressive stresses were about 10 MPa and -50MPa--30MPa, respectively, at a distance of 200μm from the indentation center. The residual stresses decreased by heat treatment at temperatures as low as 300°C below the strain point and became zero by keeping the indented specimen at temperatures close to the strain point of each glass, for 7.2ks. The resistance to decrease in residual stresses against temperature was in the order Si-B-Al-O(Ts=635°C)>Si-Al-O(Ts=570°C)>Si-Ca-Na-O(Ts=511°C) glass. The results were discussed based on the difference of the mobility of constituent ions and flow of glasses