Abstract: A method of chemical vapor infiltration and deposition includes stacking a number of porous structures in a stack in a furnace. The stack has a center opening region extending through the porous structures and an outer region extending along the porous structures. A first portion of a reactant gas is introduced to the center opening region. A second portion of the reactant gas is introduced to the outer region. The first portion and the second portion are controlled proportions thereby introducing predetermined portions of the reactant gas to both the center opening region and the outer region. The change in weight of the entire furnace, including contents, is measured during the chemical vapor infiltration and deposition process. The rate of weight change is monitored.

Abstract: A method of chemical vapor infiltration and deposition includes stacking a number of porous structures in a stack in a furnace. The stack has a center opening region extending through the porous structures and an outer region extending along the porous structures. A first portion of a reactant gas is introduced to the center opening region. A second portion of the reactant gas is introduced to the outer region. The first portion and the second portion are controlled proportions thereby introducing predetermined portions of the reactant gas to both the center opening region and the outer region. The change in weight of the entire furnace, including contents, is measured during the chemical vapor infiltration and deposition process. The rate of weight change is monitored.

Abstract: A hardware assembly is provided for controlling a first portion of gas and a second portion of gas in a furnace. The first portion of the gas is introduced to a center opening region of a stack of porous structures. The second portion of the gas is introduced to an outer region of the stack of porous structures. Most of the gas flows out of the hardware assembly from either the center opening region or the outer region while some of the gas flows out through small holes from the other region. A densification method is also provided with two densification processes in which the gas flows in opposite directions in the two densification processes.

Abstract: A hardware assembly is provided for controlling a first portion of gas and a second portion of gas in a furnace. The first portion of the gas is introduced to a center opening region of a stack of porous structures. The second portion of the gas is introduced to an outer region of the stack of porous structures. Most of the gas flows out of the hardware assembly from either the center opening region or the outer region while some of the gas flows out through small holes from the other region. A densification method is also provided with two densification processes in which the gas flows in opposite directions in the two densification processes.

Abstract: A hardware assembly is provided for controlling a first portion of gas and a second portion of gas in a furnace. The first portion of the gas is introduced to a center opening region of a stack of porous structures. The second portion of the gas is introduced to an outer region of the stack of porous structures. Most of the gas flows out of the hardware assembly from either the center opening region or the outer region while some of the gas flows out through small holes from the other region. A densification method is also provided with two densification processes in which the gas flows in opposite directions in the two densification processes.

Abstract: The invention relates to a susceptor lid for use in a CVI/CVD furnace. More specifically, the invention is directed to a lid configured to consecutively run CVI/CVD and heat treatment processes without opening the furnace. The susceptor lid according to the invention comprises: a susceptor lid body having a gas exhaust hole, the susceptor lid body having a top surface and a bottom surface; and an exhaust lid disposed over the gas exhaust hole, with a clearance between the exhaust lid and the gas exhaust hole such that exhaust gas pressure within the clearance is approximately equal to, or less than the exhaust gas pressure within the gas exhaust hole, the exhaust lid being positioned to block the majority of the radiation from below the bottom surface of the susceptor lid body.