Nanosecond pulsed laser has a larger melting area relative to ultrashort pulsed laser,so the use of nanosecond laser greatly alleviates the gap limitation on brittle transparent materials/metal materials during the joining process using ultrashort pulsed laser.In order to determine the maximum allowable gap for nanosecond laser joining of brittle transparent materials/metals and the influence of different gap conditions on the joining effect,this study examines the effects of various interface gap conditions on the macro-and microstructure as well as the mechanical properties of quartz glass/copper joints.It is found that the joint shear strength decreases from 27 MPa to 10.5 MPa with the increase of the interfacial gap,and the maximum permissible interfacial gap is about 5 pm.The reason for the large error bars in the shear strength data of quartz glass/copper joints is mainly due to the common intrinsic cracks in brittle and hard transparent materials,which include porosity and inclusion,and the existence of porosity and inclusion often leads to the shear strength of a discrete and accidental nature.In addition,it is found that the causes of cracks during nanosecond laser joining of quartz glass/copper are divided into two categories one is delayed fracture in cold cracking and the other is thermal cracking,which can be avoided by regulating the process parameters.
关键词
界面间隙/纳秒激光连接/脆硬性透明材料/金属/机理分析
Key words
interfacial gap/nanosecond laser joining/brittle and hard transparent materials/metals/mechanistic analysis
维普
万方数据