METHOD FOR CALCULATING GN DISLOCATION DENSITY OF METAL MATERIAL

• Main Authors: SAKAKIBARA YOHEI, MORISHIMA KEIKO, KUBUSHIRO KEIJI
• Format: Patent
• Language: English; Japanese
• Published: 19.11.2015
• Subjects: INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIRCHEMICAL OR PHYSICAL PROPERTIES; MEASURING; PHYSICS; TESTING

PROBLEM TO BE SOLVED: To calculate GN dislocation density more simply in a method for calculating the GN dislocation density of a metal material.SOLUTION: A method for calculating the GN dislocation density of a metal material comprises: a crystal orientation measurement step (S10) of detecting an electron backscattering diffraction pattern called the Kikuchi line by measuring an elastically deformed metal material by an electron backscattering diffraction and generating a Hough space by Hough transformation with a step size greater than 0 degrees and less than or equal to 2.0 degrees, and measuring a crystal orientation for each section in a crystal grain composed of a plurality of sections having the same area; a KAM value calculation step (S12) of calculating the KAM value of a dimension n (n is a natural number); a KAM value change rate calculation step (S14) of calculating a KAM value/ n that is a KAM value change rate from a difference KAM value of the KAM value relative to a difference n of the dimension n (n is a natural number); and a GN dislocation density calculation step (S16) of calculating GN dislocation density from the KAM value change rate. 【課題】金属材料のＧＮ転位密度算出方法において、より簡易にＧＮ転位密度を算出することである。【解決手段】金属材料のＧＮ転位密度算出方法は、塑性変形した金属材料を電子後方散乱回折法で測定し、 ステップサイズが０度より大きく２．０度以下でハフ変換してハフ空間を生成することにより菊池線と呼ばれる電子後方散乱回折パターンを検出し、同一面積の複数の区画で構成された結晶粒内において、区画ごとに結晶方位を測定する結晶方位測定工程（Ｓ１０）と、次数ｎ（ｎは自然数）のＫＡＭ値を算出するＫＡＭ値算出工程（Ｓ１２）と、次数ｎ（ｎは自然数）の差分 ｎに対するＫＡＭ値の差分 ＫＡＭ値から、ＫＡＭ値変化率である ＫＡＭ値/ ｎを算出するＫＡＭ値変化率算出工程（Ｓ１４）と、ＫＡＭ値変化率からＧＮ転位密度を算出するＧＮ転位密度算出工程（Ｓ１６）と、を備える。【選択図】図１