Al-C-Ti System Self-propagating Welding Titanium Alloy Experimental Research

SHS welding is a new application field using self-propagating high-temperature synthesis technology, SHS using quantity of heat reactions release of itself and product to achieve the same or dissimilar material welding. The influence of self- propagating welding contain many factors, including the raw material composition and reaction process parameters of the experiment etc.This experiment will choose Al - C - Ti powder system as self-propagating reaction system to carry out welding experiments, from the experiments we can get:(1)When the percent of aluminum from twenty increased to forty in the system, the product only contains Al, C and TiC, when the percent of aluminum increased to sixty percent, the percent of product of Al obviously increased, also appeared Al₃Ti phase. And with the increase of the percent of Al, grain size of TiC obviously decreased, when the percent of aluminum increased fifty percent , the particle size of TiC decreases to one microns. And the welding effect changes with the increased of the percent of aluminum, welding is best when the system content forty percent of aluminum. (2)When the C/Ti atoms ratio from zero point six increased to zero point eight ,the SHS product include Al,Ti C and Al₃Ti phase, when the C/Ti atoms ratio ,the product of SHS include Al and Ti C phase. When the C/Ti atoms ratio is zero point seven, there are a lot of branch shape of Al₃Ti, only a little of TiC, with the increases of C/Ti atomic ratio, the branch shape Al₃Ti gradually decrease, the amount of TiC Increase gradually, and the has morpholo- gy of Al₃Ti changed, from branch shape into a mass- ive shift gradually. With the increases of C/Ti atomic ratio, the porosity of SHS product in- creased significantly, the densify decline, welding is best When C/Ti atomic ratio is 1.0. (3)With the increase of relative density, the particle size of TiC is decreased in the SHS synthetic products, the pore ratio is increased, the density is decreased. observation the weld- ing from on macroscopic can see that when the relative density is 70%,the welding is the best. (4)In the micro hardness experiments , the micro hardness of titanium alloy substrate have a bit increased,the highest micro hardness of the produce of SHS were appeared when the percent of aluminum for forty , C/Ti atoms ratio for 1.0, relative density for seventy percent.(5) In the shear strength experiments, along with the increase of the content of Al ,shear stress First greaten, then decreases, the largest numerical is when forty percent . Along with the increase of C/Ti atoms ratio ,the shear stress first increases, then decreases, when C/Ti atomic ratio is 1.0,the shear stress is the largest. Along with the increase of relative density, shear stress after first greaten, then decreases ,the maximum numerical when the relative density for 70%.The experiment research the influence of the powder system for the SHS welding, to realize dissimilar material (metal - ceramic) welding provides the foundation.