Page 34 - Welding of Aluminium and its Alloys
P. 34

First solid
                                                          to form









                                                            Liquid




                                                          Increasing
                                                          area of solid








                                                          Liquid

                                                            Increasing amounts
                                                            of solid phase











                                                         Small amounts of liquid surrounding
                                                         large islands of solid


            Small amount of lowest
            melting point liquid along
            the grain boundaries



              Note that a large
              difference in melting point
              between the bulk of the
              metal and the ‘low’
              melting point films results
              in an increased sensitivity
              to hot or solidification
              cracking
                     2.11 Solidification of a metal.
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