球磨条件对Ni－Ti粉末结构转变及机械合金化速度的影响

EFFECTS OF MILLING CONDITIONS ON STRUCTURAL CHANGE AND AMORPHISATION RATE OF Ni-Ti POWDERS IN MECHANICAL ALLOYING PROCESS

用ＸＲＤ分析研究了搅拌式球磨过程中球磨条件对Ｎｉ－Ｔｉ单质混合粉末结构演化的影响．定量测定了球磨粉末微观应变、微晶尺寸、镍的晶格常数及衍射峰相对微射强度与球磨转速及装球量的关系．研究了球磨功率对球磨温升、粉末微晶尺寸，层片状结构转变的影响，确定了非晶化所需时时间与工艺条件的关系，结果表明球磨功率成粉末塑性变形能增加，微晶尺寸减小．层片组织细化，同时微观应变大，晶格常数变化快，非晶化所需时间减小．

Effects of milling conditions on structural changes of mixed 50Ni-50Ti powders in mechanical alloying have been characterized by X-ray diffraction analyses, quantitative relationships of microstrain,Crystallite size, lattice parameter and diffraction intensity with rotational velocity and ball charge and the relationship of power input with milling vial temperature, crystallite size, thickness of laminated structure were measured. The results show that the crystallite size,lamellar thickness decrease with the increasing of power input or plastic deformation energy of powders, which also result in rapid changes of lattice parameter and large microstrain, thus, amorphisation time decreased with power input increaseing.